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Full text of "Aquatic and wetland plants of southwestern United States"

i Aquatic and 
- Wetland Plants 

Southwestefn United States 



Aquatic and Wetland 

Plants of Southwestern 

United States 




Frontispiece: Sarracenia alata: a, habit, x Y>; b, flower, x 1; c, fruit, x I. (V.F.). 







WATER POLLUTION 
CONTROL RESEARCH SERIES 

16030 DNL 01/72 



Aquatic and 
Wetland Plants 

Southwestern United States 



by 

Donovan S. Correll 

Southern Methodist University 
and 

Helen B. Correll 
Botanical Editor and Researcher for 
Environmental Protection Agency 




ENVIRONMENTAL PROTECTION AGENCY 

Research and Monitoring 

Grant No. 16030DNL 
January 1972 



Library of Congress Catalogue Card Number 72-6000-67 



For Bale by the Superintendent of Documents, U.S. Government Printing Office 

Washintrton. IJ.C. 20402 - Price: $7.75 
Stock Number 6501-0177 



To 
Vivien Frazier 

and 

AiLEEN Maddox 

Whose Steadfast Help 

Made This Work Possible 




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Upon reconsideration, however, it was decided to use the political boundaries 
of those states that are considered to make up southwestern United States as the 
boundaries of our project area; namely, Oklahoma, Texas, New Mexico and 
Arizona. Since there is some interplay of species where the eastern forests and the 
western prairies join, it was thought best to incorporate these forest areas. Their 
inclusion augmented considerably the number of wetland plants, as well as strictly 
aquatics, to be treated in our research. It was our opinion that the inclusion of 
species in these forested regions would make our work not only more useful in 
the states covered by our research but also of some use to those states to the east 
and northeast of our area. We also considered that since the greater part of the 
water that is found in the lower, more arid regions is derived not so much from 
rainfall but from springs and snowfields, and other such places found in the high 
mountains, the montane vegetation that is associated with these water sources 
should also be included. The inclusion of these plants of primarily seepage areas 
that are usually confined to high mountain regions further augmented the species 
that we were to treat. 

This project was originally visualized, in early 1963, to be a taxonomic-ecologlc 
treatment, but after more than a year of vainly searching for an interested quah- 
fied ecologist to work on the project the ecological phase was reduced to what the 
taxonomists could contribute. Today, considering that "ecology" and "environ- 
ment" are so popular with almost everyone and with nearly all phases of our life, 
it seems unthinkable that, in 1963, we were unable to convince those ecologically- 
minded and -trained individuals whom we approached to take part in this project. 
We received only resistance from prospective applicants — everything from not 
wanting to get their feet wet, not wanting to do field work, not interested in 
working on aquatic plants, to "what is the need and use of doing this research?" 
Needless to say, we were disappointed by such lack of interest. In spite of this 
discouragement, a great amount of ecological and environmenal information was 
gained by our own observations that was supplemented by pertinent information 
found in literature. 

Nevertheless, this work does not pretend to be a study of the ecology of hydro- 
phytes nor of their complex physiology and morphology. Rather, it is an attempt 
to present a taxonomic treatment of the species that comprise what we know as 
hydrophytes without degenerating "into a tedious floristic catalogue," as abhorred 
by Sculthorpe (1967) and others. 

Since no ecological studies, as such, were undertaken, field work, except in 
selected localities, consisted primarily in what might be termed a random sampling 
of various types of habitats located throughout the region covered. Locations 
would be visited, often more than once during any one season, observations 
recorded, and herbarium vouchers prepared. Approximately 9,000 field collections 
were made during the course of the work, the first set of which is in the Herbarium 
of Texas Research Foundation (LL), Renner, Texas. Additional specimens are 
in the Gray Herbarium (GH) of Harvard University, The University of California 
Herbarium (UC) at Berkeley, Rancho Santa Ana Botanic Garden Herbarium 
(RSA) in California, Florida State University Herbarium (FSU), Tallahassee, 
and elsewhere. 

Distribution information within our area of study is based primarily upon the 
9,000 botanical vouchers that were collected during the course of this project, 
and upon those that were examined, where possible, in various herbaria. These 
distribution data are supplemented by a discriminate and judicial adaptation of 
distributional information provided by published monographs, revisions, Floras 
and other such basic literature that are included in our Bibliography. 

ix 



The descriptions of families and genera, while they definitely include the plants 
in our area, have, in many instances, been written so as to include plants that 
might eventually be found in southwestern United States. 

In giving habitat data for the species, in most cases only habitats that fall within 
the province of our interest are given. In other words, in the case of those species 
that are tolerant to a wide range of habitats only the aquatic or wetland habitats 
are usually cited. 

We early realized that the scope of our work could become prodigious, especially 
when we discovered that similarly appearing habitats in proximity more frequently 
than not had a dissimilar floral composition. This meant that if we expected to 
obtain a complete knowledge of the occurrence and distribution of species within 
our region it would be necessary for us to investigate as many localities as possible 
in a given area rather than to depend solely upon random sampling in few specific 
localities. 

We also realize that there are distinct possibilities that some researchers or 
otherwise interested individuals may find species that they consider should have 
been included in this work. These omissions could be due to a number of reasons, 
foremost of which would be a lack of information or a difference in interpretation 
as to what should or should not be included, or to an oversight on our part. If 
such an omitted species is found we recommend that its identity be sought in some 
one of the standard Floras that covers the particular region in which the plant 
is found. These Floras are cited in the Bibliography. 

It is also possible that some of our colleagues may question our inclusion of 
certain species, especially the woody ones. Among these might be Cephalanthus 
occidentalis, Gleditsia aquatica, Nyssa aquatica, Salix spp., Quercus spp., Platanus 
spp. and Tamarix spp. Since this treatise is not solely a biologic one but is also 
concerned with the economics of water and its utilization by plants, species such 
as the above have been included. Also, since they grow either directly in water, in 
saturated soils or along water courses they must be considered to be heavy users 
of water. The same principle is applied for the inclusion of plants that grow in 
such places as alpine and subalpine wet meadows, on seepage slopes below snow- 
fields, and in seepage along streams and about springs. These plants draw heavily 
upon the very source of water that ultimately makes up the streams and rivers at 
lower elevations. They also form turf that aids in the control of water flow from 
such places. 

When originally proposed, this project was intended to be concerned with 
aquatic and wetland plants in every type of habitat that fitted into these categories. 
However, when support was first obtained from the National Institutes of Health, 
officials of that agency suggested an administrative change for the title so as to 
be more in line with the work and purpose of their organization. The title change 
was to be "Aquatic and marsh plants of polluted waters in southwestern United 
States." With this new title, we considered having the subtitle read "Paludal 
Plants of Polluted Places." 

So as to live up to the administrative title as much as possible we have paid 
particular attention to the sewage effluents from small and large cities, essentially 
open cesspools of villages and small towns and even the seepage from large septic 
tanks of motels, homesite developments and other such places that often were 
flowing into lakes within a few yards of beaches where children and their parents 
were playing and swimming. We never felt delinquent when we worked along 
rivers or streams, and in and about lakes and other impounded waters, because we 
realized that we were still working within the administrative bounds of our 
project. We considered unpolluted only those streams and water bodies from which 
we could drink directly. Needless to say, we would have perished from thirst if we 



had confined the quenching of thirst to such places. One should be apprised from 
the above that we were able to complete our project essentially as it was originally 
proposed. 

About midway in our research that was begun in 1964, public outcry was raised 
against pollution and for conservation and the preservation of a balance in nature's 
ecology. We have, consequently, taken into consideration this biotic interest of 
man in his environment. Since this explosion of public interest in our environment 
and its ecology practically every author or would-be author has written something 
on these now popular subjects to the extent that there exists very little one can 
say without repeating what someone has already said. Neverthless, since we believe 
that some ecological background information to our work would be useful we have 
presented it in the form of summarizing what is now common knowledge with a 
sprinkling of our own personal observations. 

This work, however, is not, and never was, intended as a treatise to cover all 
facets of water pollution. It does, however, attempt to deal with one of the most 
obvious and important factors — higher plant life — in the ecosystems of our lakes, 
ponds, streams, marshes, swamps, bogs and wetlands, generally. Also, since, at least 
administratively, this project has been officially classified as "Aquatic and Marsh 
Plants of Polluted Waters . . .," we believe that at least a brief summary should 
be given of the kinds and types of pollution that is to be expected or that actually 
exists in most of the habitats that we have studied. 

In our work we are often asked what can be done about water pollution. We 
always say that from this minute on no facility, whatsoever, should be permitted 
to be built and put into operation unless it is so planned and structured as to 
create no further pollution. Then, methodically and persistently, our present pol- 
luters and their pollutants should be eliminated or corrected without delay. We 
are pleased to note that the newly created Federal Government Environmental 
Protection Agency plans to do just as we have always recommended to our 
listeners. 

One of the best means for establishing and inculcating in our people a lasting 
appreciation of nature is the teaching of natural history in our schools, starting 
with Kindergarten and carrying the program through the senior year in college. 
All colleges, universities and other institutions of higher learning should have 
established long ago a required Natural History course for all freshmen students. 
For many years we and others, among whom is George S. Avery, former Director 
of the Brooklyn Botanical Garden, have "preached" that this emphasis on natural 
history should be made a part of every student's educational curriculum. This 
would not only include touching upon certain phases of biology, especially those 
with which one may make daily contact, but also upon related sciences, such as 
geology and meteorology, that make up the total environment. The end re- 
sult would be a population that would really appreciate and protect every 
phase of the world in which we live. The required or elected courses such as 
botany, zoology, entomology, mycology and so forth, that would fall into a. com- 
prehensive natural history course, are given by most college and university depart- 
ments as if the student taking the course is to become a professional in that 
particular discipline. To teach an appreciation of nature in all its aspects to the 
laymen students has apparently never occurred to most teachers. For this reason, 
an old fashioned course in Natural History for the lay student is, and has long 
been, desperately needed in every institution of learning so as to not only enlighten 
the student but to also place emphasis upon his understanding and appreciation 
of the world and its inhabitants so that he will become a part of Society that will 
appreciate and protect our Environment. 

xi 



Perhaps, at last, there will be raised a generation of champions of Nature, or 
what we vulgarly call "The Environment," in spite of our adult population. Our 
modem day youth, in its intransigence, is rapidly becoming apprised of the fact 
that instead of continuing to live "on" Nature we absolutely must, before it is too 
late, learn to live "with" Nature. 

A major problem for the conservationist in our area, as well as in all areas 
that support considerable wildlife, is the indiscriminate draining of marsh areas, 
swamps and savannahs. A more recent tendency of potentially disastrous portence 
to wildlife is the dredging and "straightening out" of meandering streams. Instead 
of flooding during high water, with consequent water renewal in adjacent or nearby 
marshes and wetlands, the habitations of much of our wildlife, these newly created 
"ditches" allow the water to rush with tremendous scouring effect down their raw 
troughs. This, in itself, creates a pollutant condition in that the water is usually 
badly clouded from silt which, in turn, is frequently dropped in lakes to build up 
their silted bottoms or carried out into oceans to pollute their estuaries. 

We have tried to present our subject matter as objectively as possible, although, 
as botanists, we tend to lean toward the survival of plant life, especially when we 
are in the process of studying it. 

Support for the initial phases of this research, begun in September, 1964, was 
provided by the Division of Water Supply and Pollution Control, later changed 
to the Federal Water Pollution Control Administration, National Institutes of 
Health, United States Department of Health, Education and Welfare (Grants 
WP 00685-01 to 04A1 and 03S1). We are especially grateful to Dr. Robert A. 
Littleford of the National Institutes of Health, who initially approved our project 
for support. In September 1966- this agency was transferred to The United States 
Department of the Interior as the Water Quality Control Administration, where, 
thanks to Dr. J. Frances Allen, support for our project was continued until 
December 31, 1970 (Grant 16030 DNL), after which it was transferred on 
January 1, 1971 to the Environmental Protection Agency. We are, indeed, grateful 
to each of these government agencies and their administrators for the support 
we have received during the course of this research. We are also grateful to the 
Environmental Protection Agency and its administrators for support to publish the 
work. 

Without the cooperation and help of various individuals and institutions it 
would have been most difficult for us to pursue and complete this work. The 
officers and trustees of Texas Research Foundation tolerated our stay at their 
institution so that we could complete this task. We are especially indebted to 
John R. Crutchfield who worked with us from May 1965 through July 1967 as a 
plant collector, and to Richard S. Mitchell who collected plants for our project 
during the summer of 1967. 

The generosity of Herbert L. Mason, of the University of California at Berkeley, 
in permitting us to use a great many illustrations from his excellent work, "A 
Flora of the Marshes of California" (1957), is gratefully acknowledged. Dr. 
Mason also generously permitted us to use some of the information and data in 
his treatise. 

We are especially fortunate to be able to use, through the generosity of Robert 
K. Godfrey, of the Florida State University at Tallahassee, a large number of the 
drawings that he had made for his temporarily suspended project on the aquatic 
and marsh plants of Florida. We were thus able to illustrate many of the species in 
eastern Texas and Oklahoma that are also common to Florida. We are, indeed, 
most grateful to Dr. Godfrey for the privilege of using these excellent drawings 
which he plans to use eventually when his work is published. 

In undertaking a problem of this magnitude we have had to resort to a con- 
siderable amount of judicious compilation from the published work of many of 

xii 



our colleagues. Especially to be mentioned here are the various Manuals and 
Floras that cover to some extent plant species that occur in our region of investi- 
gation. By way of acknowledgment and also as a ready reference, all of these 
works that were consulted have been included in the Bibliography. We are most 
grateful to have had these publications available to us. Since the subject matter 
covered has been expanded to a considerable degree beyond the scope of that 
of most past workers in this field, these ready references were especially helpful. 

We would like to note especially the work of C. D. Sculthorpe (1967), "The 
Biology of Aquatic Vascular Plants." It is a most lucidly written treatise, and 
one from which we have derived much help and information. A great amount of 
pertinent and valuable information regarding these plants has been compiled in 
this most useful work, and it is here highly recommended to all interested parties. 

Research on this project ran concurrently for several years with work on the 
preparation of Correll's and Johnston's recently published (1970) "Manual of the 
Vascular Plants of Texas." We are, indeed, grateful to our fellow-author of the 
Manual, Marshall C. Johnston, of the University of Texas at Austin, and to the 
many collaborators for the privilege of using in this work some parts of their 
contribution to the Manual, where they and their individual contributions are 
acknowledged. We are equally grateful to those individuals whose published 
materials were adapted for use in the Manual, and acknowledged there, for the 
use of some parts of their material in this work. Where new material has been 
adapted for this work it is acknowledged where this adaptation occurs. 

There are many individuals, too numerous to mention by name, who have been 
directly or indirectly helpful to us in our research, and to whom we are most 
grateful. Foremost among these are the curators of various herbaria in which 
specimens from our region are deposited. In regard to specimens, we wish to 
acknowledge especially those that were received from several individuals who made 
a special effort to collect aquatic plants for us. These are Frederick R. Gehlbach, 
of Baylor University, who also joined us in some field work in Arizona, Jimmy R. 
Massey, of Texas A&M University, Charles R. Hutchins, of Albuquerque, New 
Mexico, and Elray S. Nixon, of Stephen F. Austin State College. We are also 
grateful to Alan R. Smith, of the University of California at Berkeley, for his 
having clarified for us a part of the difficult genus Thelypteris, and to Neil 
Hotchkiss, now retired from the Patuxent Wildlife Research Center, U. S. Dept. 
of the Interior, for his thoughtfulness in sharing his experience with us at the 
beginning of this project, and for his continued interest in our work. 

Two botanists who accompanied us on field trips and were especially helpful 
are Eugene C. Ogden, New York State Botanist, Albany, and Henry K. Svenson, 
United States Geological Survey, now retired. 

In addition to help received from professional botanists, several highly skilled 
amateurs in Texas have either directed us to new elements in our aquatic flora or 
have provided assistance in one way or another. Among these are Geraldine E. 
Watson of Silsbee, Peggy A. Amerson of Mt. Pleasant, Jim D. Bowmer of 
Temple, and Raymond J. Fleetwood of Angleton. 

It is impossible to thank sufficiently the artists who have patiently and painstak- 
ingly delineated the often intricate and complex species. We are especially indebted 
to Vivien Frazier, with whom we have been associated in botanical art work for 
many years, for her faithful attention to the most exacting details in the rendition 
of her drawings. She has been of inestimable help to us. We are also grateful to 
Jane W. Roller and Phoebejane Horning who prepared several of the drawings 
used in this publication for works previously published by the senior author, and 
to Regina O. Hughes, who previously made drawings for the senior author's 
work on tuberous Solarium species of North America and Central America, for 
several of her plates that were recently published in Clyde Reed's "Selected Weeds 

xiii 



of the United States" (1970), and several plates of Hibiscus. We are most grateful 
for the privilege of using some of the grass spikelet drawings by Agnes Chase, 
published in Hitchcock and Chase's "Manual of the Grasses of the United States" 
(1935, 1951). We are grateful for the privilege of using drawings of several 
orchids by Blanche Ames Ames and Gordon W. Dillon, and of several species of 
Umbelliferae by Mildred E. Mathias. To the various artists whom we have not 
known personally but whose work we admire and are grateful to include in our 
publication, we extend our most sincere thanks. These are Mary Wright Gill and 
Edna May Whitehorn who made most of the drawings published in Hitchcock 
and Chase's grass manual; Mary Barnas Pomeroy, Patricia Verret Reinholtz, 
Robert Mill and Emily Patterson Reid, who prepared the drawings published in 
Mason's "A Flora of the Marshes of California" (1957); Barbara N. Culbertson 
and M. Grady Reinert, who prepared the drawings for Godfrey's yet unpublished 
research on the aquatic and marsh plants of Florida. We are, indeed, grateful to 
each of these individuals for his or her contribution to this project. 

The careful and exacting work of Mrs. Aileen Maddox in typing the manuscript 
and her assistance in all other phases of the research we gratefully acknowledge. 
Her enthusiasm for the project frequently lifted our sagging spirits. 

As noted before, the main purpose of this work, as is that of any such manual, 
is to provide a means for the identification of the aquatic and wetland plants in 
the region under consideration; namely, southwestern United States. For the most 
part, we believe that the text is uncomplicated and straightforward and needs no 
explanation. Several points, however, should be clarified. Although the families 
are arranged phylogenetically essentially in accordance with the Engler and Prantl 
System, many of the genera and the species within a family or genus, respectively, 
are not arranged in phylogenetic order. This phase needs more study than time 
allowed for the present. In the Keys the first number in each couplet, except for 
the first pair, is accompanied by a number in parenthesis. This number in paren- 
thesis refers back to the previous couplet from which the present one was derived. 
With this aid one can quickly and readily retrace one's steps back to the very 
beginning of the Key if need be. The branches or "legs" of each couplet are 
terminated either by a plant name or by a number in parenthesis that refers to a 
subsequent couplet. In regard to the measurements and numbers of parts given 
in some sections of the text, as "petals (5-) 7-9 (-12) mm. long," such may be 
interpreted as "petals usually 7-9 mm. long but sometimes as short as 5 mm. or 
as much as 12 mm. long." TTie less common extremes in measurements and 
numbers of parts are enclosed in parentheses. 

We can not over-emphasize the need for exerting the most strenuous effort 
to clean up our total environment. Our close observation of much of the aquatic 
and wetland habitats in southwestern United States has indelibly impressed upon 
us the appalling conditions that now exist in many of these places that are of Vital 
interest to plants and animals, and to the general well-being of mankind. Along 
with the present cleaning, and the future protection, of our environment will 
come conservation. One follows the other! 

Finally, we believe that any kind of work such as ours should represent a 
combination of our efforts and those of our many colleagues. We are grateful 
for their work which has contributed immensely to the fulfillment of the present 
task. 



Donovan S. Correll 
Helen B. Correll 

\iv 



Contents 



Authors' Preface vii 

Introduction 1 

I. Habitats of Aquatic and Wetland Vascular Plants 2 

II. Peculiarities and Distribution of Aquatic and Wetland Vascular 

Plants 6 

III. Economics and Control of Aquatic and Wetland Vascular Plants 10 

IV. Pollution in Aquatic and Wetland Habitats 12 

Key to the Major Groups and Families of Aquatic and Wetland Vascular 

Plants 17 

Descriptive Flora 37 

I. Pteridophyta 37 

II. Gymnospermae 79 

III. Monocotyledoneae 85 

IV. Dicotyledoneae 734 

Glossary 1705 

Abbreviations and Signs 1733 

Selected References 1737 

Index 1739 



XV 



Introduction 



Southwestern United States, as we have come to know it, is a vast and complex 
region that includes practically any ecosystem that can be found in the world 
today, exclusive of polar regions. The area studied extends from the warm- 
temperate mesophytic forests and Gulf Coastal Plain of southeastern Texas, and 
the subtropical Rio Grande Valley, to the alpine summits of the Rocky Mountains 
in New Mexico and Arizona, and the Sonoran Desert of southwestern Arizona. 

For the most part, our region is one of high evaporation which, even in a single 
season, can greatly affect the composition of various plant communities. This 
high rate of evaporation that causes drastic fluctuations in the water level of a 
water body can quickly alter or change entirely its ecology. Through desiccation, 
with the lowering of the water level, much of the vegetation occupying the 
marginal zone can perish, while the submersed and floating vegetation may be 
adversely affected by lack of light and oxygen sufficient to carry on the life 
processes. 

In addition to this drastic evaporation from open water surfaces and land, 
vast quantities of water are transpired from plants. Our work, which we con- 
sider to be a water-economy oriented botanical treatise, is concerned primarily 
with these plants that have the greatest impact upon our water resources. For 
this reason not only those plants that live in open water or marsh areas are treated 
but also those plants that are known as phreatophytes, or those plants whose 
roots tap the ground water. These latter plants are considered by some authorities 
to pose a definite threat to the meager water resources in some parts of south- 
western United States. Many government and private foresters consider that such 
plants as the salt cedars (Tamarix) that grow especially in alkaline or saline 
floodplains, about lakes and on streams and river banks use water wastefully and 
are of little or no benefit. These foresters advocate the cutting and rooting out 
of these plants. This, of course, would be the simplest and probably the costliest 
procedure. We believe, however, that more consideration should be given to a 
long-range, more permanent control. 

Surface waters of southwestern United States are almost entirely utilized, and 
ground water is being pumped at a rate that exceeds the estimated recharge. 
In some areas in this vast region the average depth to ground water has been 
found to be increasing at an annual rate in excess of 20 feet. In the light of 
such frightening statistics we should realize that we should delay no longer in 
learning all we can about our water resources and every factor that may have 
any kind of influence upon them, no matter how trivial such may seem to be. 

Our decision as to what plants should be included in this work has been 
influenced as much by practical and utilitarian factors as by strictly biological 
considerations. In respect to interpretations, we have found that the most 
exasperating and frustrating part of the work is that which involved decisions as 
to what species to include; in other words, what should the limits be? After being 
certain that all strictly aquatic and wetland species have been included, we found 
that the periphery of inclusion had a tendency to spread to the margin of 

I 



mesophytism. Since all vascular plants depend more or less upon water for their 
very existence, and are thus biologically "aquatic" to a greater or lesser degree, 
a premise to determine just how much effect a particular species has upon the 
water resources of a given area could be carried to a ridiculous extreme. 

In the Introduction to his "A Flora of the Marshes of California," Mason has 
expressed in unequivocable terms the way we feel about the limitation or lack of 
limitation that should be placed upon plant species to be included in a work such 
as this. We agree with him entirely when he says that the circumscription of the 
field of research in this type of problem is not clear cut and that its boundaries 
are usually highly artificial. We not only include the wholly aquatic species but 
also the important and frequently critical amphibious species. But, as Mason 
succinctly states, when we include ". . . . the amphibious species, we are drawn 
immediately up on the shore, where the naturalness of the communities and the 
overlapping of their species lead us farther and farther away from water." 

For convenience and simplicity, the term "vascular hydrophytes" has frequently 
been used here to include both aquatic and wetland plants. 

I. Habitats of Aquatic and Wetland Vascular Plants 

Several outlines have been proposed to cover the various habitats in which 
aquatic and wetland plants are to be found. For our purpose, and because it is 
more far-reaching than most others, the one proposed by Mason, in 1957, is the 
best yet devised. With some reorganization and the addition of several habitats 
peculiar to our region, Mason's outline is as follows: 

I. Water standing or essentially so. 

A. Presence of water permanent and level fairly persistent. 

1. Open water surface the most conspicuous feature. 

a. Fresh water: lakes, ponds, reservoirs. 

b. Salt water: salt lakes, bays and oceans, estuaries, lagoons. 

2. Vegetation more conspicuous than water surface. 

a. Vegetation dominantly herbaceous. 

aa. Marshes: alkaline marshes, salt marshes, brackish marshes, fresh- 
water marshes, 
bb. Bogs: quaking bogs, floating bogs, evergreen shrub bogs. 

b. Vegetation dominated by trees and/or shrubs, 
aa. Swamps, bay-galls. 

B. Presence of water intermittent or at least the level widely fluctuating. 

1. Intermittence seasonal: vernal pools, playa lakes, vernal marshes, 
savannahs. 

2. Intermittence tidal: Salt-water marshes, seasonally salt and fresh-water 
marshes, fresh-water marshes subject to tidal influence. 

II. Water flowing: live streams, intermittent streams, irrigation ditches, drain- 
age canals, hillside bogs, streamside marshes. 

III. Wet soil adjacent to habitats with standing or flowing water: strand areas, 
riparian lands, lacustrine lands, wet meadows, seasonally wet floodlands. 



There are very few natural lakes in southwestern United States, and these 
are to be found mostly at high elevations in the mountains. Their creation is 
solely the result of local conditions. The great ice sheets that formed lakes such 
as those found in Wisconsin never reached this region. There are, however, 
innumerable man-made lakes, reservoirs, ponds and stock tanks to be found in 
southwestern United States, and many great and small rivers with numerous tribu- 



taries dissect this region. In eastern and southeastern Texas are to be found 
evergreen shrub bogs and savannahs. In this same area as well as in Oklahoma 
are to be found swamps, alluvial woodlands and floodplains, and along coastal 
Texas are to be found vast fresh and brackish marshlands, rice paddies, ocean 
beaches and shores, drainage canals, bays, reefs, estuaries and sluggish streams. 
Inland, especially in areas of low rainfall throughout our region, are to be found 
irrigation ditches, lakes on salt deposits, and saline and alkaline flats that are 
periodically inundated. In these more arid regions are to be found rivers and 
streams that may have their beginnings in springs and artesian wells at high 
mountain elevations but which disappear as dry beds as they flow into the 
lowlands. 

When a body of water is created by man, usually the first obvious plant 
invaders are cat-tails (Typha); their essentially weightless wind-blown seeds 
would appear to be hovering nearby. Next, or occasionally invading simultaneous 
with cat-tails, are bulrushes (Scirpus). These early invaders first establish them- 
selves in shallow water and then, through clonal growth by means of rhizomes and 
stolons, migrate out into deeper water where they form dense conspicuous colonies 
that provide a habitat for small floating plants and they give protection and 
shelter to various wildlife. 

As noted above, similarly to natural lakes in the North, these southwestern 
artificial lakes and ponds, when stabilized, also typically have several zones of 
vegetation. The outermost zone is one of emergent vegetation, wherein the plants 
are rooted in the lake substrate and the photosynthetic organs stand above the 
surface of the water. Here we find primarily grasses, rushes and sedges, among 
which are spike rush (Eleocharis), sedge (Carex), bulrush (Scirpus), bur-reed 
(Sparganium), cat-tail (Typha), water plantain (Alisma) and arrowhead 
(Sagittaria). 

The next zone, moving lakeward, is that of floating-leaf plants. These plants 
may be rooted in the lake substrate or they may be free-floating. In either case, 
they have their leaves floating on the surface of the water, or, in some instances, 
with some leaves raised above the surface of the water. Among these plants are 
water shield (Brasenia) , yellow water lily (Nuphar), white water lily (Nymphaea) , 
pondweed (Potamogeton) , water ferns (Azolla and Ceratopteris), water hyacinth 
(Eichhornia crassipes), water lettuce (Pistia Stratiotes) , duckweed (Lemna), 
duckmeat (Spirodela) and water meal (WoJffia). 

The innermost zone is composed of entirely submersed plants or those with 
only their flowering and fruiting parts emersed or floating. These plants are 
characterized by having long, sinuous or straplike leaves and with a bunched 
growth habit and finely dissected highly branched leaves. These plants derive gases 
and nutrients from the water in order to survive. Among these plants are milfoil 
(Myriophyllum), hornwort (Ceratophyllum) , naid (Najas), waterweed (Egeria, 
Elodea) and fanwort (Cabomba caroliniana) . The non-vascular plants, stonewort 
(Chara and Nitella), are also frequently abundant in this zone. 

This phenomenon in nature that can be "a thing of beauty," the zonation of 
life forms of undisturbed, natural aquatic vegetation that becomes established 
and is so prevalent about the shores of lakes, ponds, canals and slow-moving 
streams, when once destroyed or disturbed by man's "improvements," or his 
propensity for gross pollution, is essentially impossible to re-establish. Since this 
zonation is the result of natural succession by plants in this type of habitat, they 
should be left undisturbed if man is to maintain his aquatic environment as it 
should be in such places. 

Coastal marshes, known to support numerous species of plant and animal life, 
are among the most important of all natural habitats. In these areas a very slight 
change in elevation will also mean somewhat of a change in the vegetative cover. 



Our only development of coastal marshlands occur on the Gulf Coast of Texas. 
The area is characterized not only by salt meadows, salt marshes, tidal flats and 
estuaries, but also by fresh-water marshes, swamps, meandering bayous and 
resacas, and sloughs. Some of the nation's largest wild-life reservations, especially 
for waterfowl, are to be found in this region. 

The salt marsh areas typically support species of Carex, Cyperus, Eleocharis, 
Rhynchospora, Scirpus, several cordgrasses (Spartina) and seashore saltgrass 
(Distichlis spicata) . 

Aquatic plants abound in this region. Among these are Wolffia, Wolffiella 
lingulata, parrot's feather (Myriophyllum), pondweeds (Potamogeton), duck- 
weeds (Lemna), duck meat (Spiroclela), water-lilies (Nymphaea), cow-lily 
{Nuphar luteum) , Hygrophila lacustris and arrowheads {Sagittaria) . The bene- 
ficial aquatic plant species as well as open water for fish and wildlife in many of 
the streams, canals, lakes and ponds are threatened by several introduced noxious, 
aggressive species. Foremost among these are the water hyacinth (Eichhornia 
crassipes) and alligator weed {Alterncmthera philoxeroides) . The native cat-tails 
(Typha) also belong here. Other species that can and may prove to be trouble- 
some in this and other parts of our region are aquatic species of water-primrose 
(Ludwigia), water-lettuce (Pistia Stratiotes), common frogbit {Limnobium 
Spongia) and American featherfoil {Hottonia inflata). In bays and open waters 
along the Gulf Coast are to be found such marine species as Cymodocea filiformis, 
Thalassia testiidinum, Halophila Engelmannii, Halodiile Beaudettei, and rarely 
Posidonia Oceania. Some of these are often washed up on the beaches along the 
coast. 

Shallow ponds and backwaters of river margins are usually the beginnings of 
fresh-water marshes. These marshlands are treeless expanses, often with dense 
growths of herbaceous plants such at cat-tails, grasses and sedges. In marsh pools, 
where the water is deeper, water lilies, pondweeds and other plants become estab- 
lished. 

Plants such as cat-tails, bulrushes, bur-reeds, Sagittarias, Pickerelweed. Peltandra 
and button-bush are rooted in mud in shallow water on the edge of ponds and 
quiet backwaters of rivers. In ponds, for instance, plants grow outward from the 
bank and shallow water to deeper water where water-lilies, Nuphar and Brasenia 
take their place. On out into the deepest open waters both rooted and free-floating 
plants such as the carnivorous bladderworts, pondweeds, Cahomba and Cerato- 
phyllum are found. Through the years as the plants on the outer periphery con- 
tinue to move toward the center of the pond they shade and crowd out the floating 
and submerged plants that die and contribute to the filling of the pond. As the 
filling continues the vegetative composition of the pond is affected until a marsh 
is evolved — a treeless tract of water and aquatic plants. 

With continued filling by dead plants and silt the marsh, in turn, will give way 
to the sedge-filled meadow that, with the invasion of trees and shrubs, will even- 
tually become a wooded swamp. 

Littoral vegetation zones similar to those found in lakes are often found along 
streaYns, especially if shallow water areas occur. Pickerel weed {Pontederia 
cordata). smartweed (Polygonum) and various grasses and sedges are often to be 
found in such areas. 

Similarly to our lack of glaciation-formcd lakes, our region does not have 
the type of bogs that are characteristic of far northern glaciated regions. Some 
of the bogs developed in the high mountains of New Mexico and Arizona 
approach these northern bogs, but they lack most of their characteristics. In 
glaciated country, lakes formed by ice often have relatively steep banks and poor 
drainage that make them conducive for the formation of bogs. True bogs are 
characterized by having low-growing shrubs and sedges in sphagnum mosses. 



These often form floating or stable mats supported by a peaty mass of partly 
decomposed plants. The outer edge of the bog has various types of tree species, 
determined by that part of the world in which the bog lies. 

In small lakes in eastern and southeastern Texas floating mats are occasionally 
formed where Decodon borders the water. Sedges, rushes, various species of 
Hypericum and other such plants commonly grow upon these floating or quaking, 
somewhat stabilized mats. Various evergreen or semievergreen shrubs and small 
trees often border these lakes, among which are yaupon {Ilex vomitoria) , bay-gall 
bush (I.coriacea), leatherwood {Cyrilla racemiflora) and viburnums. 

In most bogs, especially at great depths, there is little oxygen and, along with 
acids formed by peats, decay is slow and fallen plants deposited in them often 
only partly decay to become more peat. Because of their stagnant, usually highly 
acidic environment, most bogs have their own peculiar flora, usually dominated by 
thick-leaved shrubs and herbs. 

Two distinctive types of habitats, the evergreen shrub bog and savannah, occur 
to a limited extent in our area. The savannahs are found only in southeastern 
Texas and the bogs in southeastern and to some extent in eastern Texas. 

In pockets throughout eastern and southeastern Texas are found not only ever- 
green shrub bogs but also open seepage slopes and cypress-tupelo swamps. The 
latter also occur in southeastern Oklahoma. These usually develop in sandy, 
seepy areas, either on or at the bottom of slopes, in scrub oak-pinelands, or in 
permanently wet depressions in savannahs. They are characterized by usually 
having peat moss (Sphagnum) present in varying degrees. The shrubs in and 
about these habitats are often evergreen or semievergreen. They consist mostly 
of viburnums, hollies, rhododendrons, bay laurel (Magnolia virginiana), wax- 
myrtles, hypericums, dogwoods, vacciniums, leatherwood (Cyrilla racemiflora), 
Lyonia, Itea, and occasionally a sprinkling of poison sumac (Rhus vernix). Often 
the herbaceous vegetation is quite different from that of the surrounding country, 
and is represented by such uncommon species as nodding-nixie (Apteria aphylla), 
Bartonia texana, Viola lanceolata, grass-of-Parnassus (Parnassia asarifoUa), 
bogmoss (Mayaca Aubletii), pitcher plant (Sarracenia alata) , rose pogonia 
(Pogonia ophioglossoides) , bearded grass-pink (Calopogon barbatus), small wood 
orchid (Habenaria clavellata) and yellow fringed orchid (H. ciliaris) . 

In extreme southeastern Texas, centered in Jasper, Tyler and Newton counties, 
are savannahs of broad, level, grassy, open pinelands. These are characterized by 
a fluctuating water-table, often found at or near the surface, and they support 
a rather distinctive and interesting marshy and wetland flora. This includes 
several orchids, as the snowy orchid (Habenaria nivea), crested fringed orchid 
(H. cristata), grass-pink (Calopogon pulchellus) and several species of ladies' 
tresses (Spiranthes) , yellow stargrass (Aletris aurea), pipeworts (Eriocaulon) , 
whitehead bog-button (Lachnocaulon anceps), several meadow beauties (Rhexia), 
clubmosses (Lycopodium) , milkworts (Polygala), small butterwort (Pinguicula 
pumila) , bluehearts (Buchnera), sundews (Drosera), seedboxes (Ludwigia) and 
numerous sedges, grasses and bulrushes that are indigenous to this type of com- 
munity. The savannahs and shrub bogs, where they occur in proximity, commonly 
grade into one another. Plants in this border-zone are often a mixture of those in 
the two communities. 

The swamp, a wetland covered with trees and shrubs, is usually developed 
from a marsh. Typically wet and occasionally flooded, swamp forests often 
persist for a long time, especially when they are associated with streams that 
periodically overflow. 

Originally an effort was made to coordinate pH and water temperature with 
the exact place of growth for a species, such as those of Potamogeton, but it was 
soon realized that such data, as we had intended using it, were essentially mean- 



ingless. After we discovered that pH and water temperature often varied at 
minute distances, both laterally and vertically, this time-consuming routine was 
discontinued. 



II. Peculiarities and Distribution of Aquatic and Wetland Vascu- 
lar Plants 

Aquatic plants are paradoxical in that while many are of ^<reat economic import 
in relation to the existence, reproduction and conservation of wild life they may 
simultaneously be a hindrance and detriment to man's hydrological activities such 
as those involving navigation and irrigation. 

The establishment and existence of wetland plants in their particular habitat 
is much less complicated than that for strictly aquatic plants. To exist under 
water, vascular plants must have sufficient light and critical gases to carry on 
photosynthesis. The depth at which they grow depends largely upon the intensity 
and spectral composition of light. This becomes especially critical in waters that 
are variously polluted. Sedimentation created by floods and erosion, and turbidity 
as a result of dissolved organic matter and suspended organic and inorganic parti- 
cles, may cloud and discolor the water and reduce to a bare minimum the possi- 
bility of a plant carrying on the photosynthetic process. 

As has been noted by other researchers, individuals of some species grow under 
a single set of environmental conditions, while the individuals of other species 
will occur under the selective regime of different sets of environmental conditions. 
These latter species exhibit a wide degree of tolerance, such as cat-tails (Typha), 
ZannichelUa, Najas, and Riippia, usually found in fresh-water situations but that 
also can tolerate saline and alkaline conditions. The quality of water often, but 
not always, determines the plant community that will be developed in the environs. 
There is little question, however, that salinity has a critical and intricate influence 
upon the composition and development of maritime and littoral ecosystems. 

While various physical and chemical factors of the aquatic environment have 
a definite influence upon the life activities of vascular hydrophytes, the converse 
is also true as has been succinctly stated by Sculthorpe (1967. p. 415). 

"As a result of the relatively restricted volume of any inhabited body of water, 
aquatic vegetation exserts a much more profound influence upon its environment 
than does terrestrial vegetation. Through their photosynthesis and respiration, and 
their manner and rate of growth,, vascular hydrophytes may have very significant 
efi'ects upon such environmental factors as the concentrations of dissolved oxygen, 
carbon dioxide and ammonia, mineral nutrient supplies, pH value, light penetra- 
tion, current velocity and rate of silting. These effects can wield a direct or in- 
direct influence on the lives of other aquatic organisms, notably the microflora 
and fauna for which the hydrophytes may provide support, shelter or food. The 
impact of hydrophytes on the environment and on biotic relationships increases 
as the volume of the water-body diminishes; plants are most significant in ponds, 
canals and stagnant swamps, and in most rivers, which arc usually shallow com- 
pared to lakes and so contain a relatively greater concentration of plants. Analysis 
of these ecological interactions presents a formidable problem: the tremendous 
variation in local edaphic and biotic conditions invalidates all but a very few 
generalisations." 

The ecosystems of aquatic and wetland habitats, though not at all consistent 
as to their floral content, are made up of characteristic ecotypes for each kind 
of system. In other words, the species composition of a given ecosystem may vary 
in accordance to its geographical location but each kind of habitat usually has its 
characteristic type of flora. 



Although most species readily fall into one or another ecotype, in some in- 
stances individuals belonging to the same species, such as in Potamogeton nodosus 
and Polygonum amphibium, may occur as submersed or floating aquatics to am- 
phibious, riparian or strand plants rooted in mud. These plants usually, but not 
always, differ somewhat in habit, in accordance to the ecotype in which they are 
found. 

We have found, as other have found before us, that aquatic and wetland plants 
are not always dependable and of long-endurance in their particular habitats. A 
species abundant in one season may disappear for one or more seasons only to 
reappear in a later season. There are various possibilities as to why these plants 
behave thusly. A close approach to temporary extermination might result from 
overfeeding by wildlife; a change in the ionic composition of the water might be 
critical; especially in the case of vegetative reproduction, some water plants, as in 
many orchids, might have a longer resting period than just one year; fluctuating 
water levels might create physiological problems for the species. 

Analagous habitats may be found in entirely different parts of our region and 
under an entirely different set of factors, but they may reveal certain similarities. 
For instance, the Weches fossil formation near San Augustine, Texas that is seepy 
and wet only in the spring long enough to support to maturity the annual crucifer, 
Leavenworthia aurea, is comparable to tidal zones where the usually perennial 
plants that occupy such zones must have a periodic replenishment of water in 
order to thrive. Under both situations the water needs of the plant are met at 
critical times to assure propagation and/ or continued survival. 

Vascular plants that are strictly aquatic, although relatively few in number 
when compared to their dryland terrestrial relatives, offer a multitude of taxo- 
nomic difficulties because of their diversity of habit and bewildering variations that 
include heterophylly and peculiar modifications in sexual and vegetative repro- 
duction. 

Heterophylly, the presence on a single individual of two or more distinct types 
of leaves, in habit, shape and/ or anatomy is prominently displayed in many 
aquatic species in such genera as Callitriche, Potamogeton, Sagittaria, Rammculus, 
Cabomba, Myriophyllum, Proserpinaca, Alisma, Armoracia and Echinodonis. 
This leaf difference in the same individual has created problems in the identifica- 
tion of many species in the above, as well as other, genera. This unique charac- 
teristic must be taken into consideration in dealing taxonomically with these 
species. 

Peltate leaves, as in Nelumbo (Fig. 447), are considered to be the most 
mechanically efficient of all types of floating leaves. Although the leaves of 
Nymphoides (Fig. 1) do not have the thickness and toughness of such species as 
in Nymphaea, (Fig. 442) and Nuphar (Fig. 443), they do demonstrate the 
characteristic leaf of many floating leaved plants in their rounded blade and 
entire margins. The wax bloom of the cuticle on the upper surface, as in all plants 
with floating leaves, prevents excessive wetting of the leaf. The petioles that sup- 
port these leaves are strong and pliable, and their buoyance and support are 
further enhanced by air-filled lacunae on the lower surface which are centered 
and more prominent along the midrib and near or about the petiole. 

Floating leaves, in being exposed to both air and water at the same time, are 
rather unique and they have developed features that enable them to better with- 
stand the hazards of their environment. 

Most of our emergent hydrophytes produce aerenchyma — a spongy tissue de- 
veloped mostly on the stems and branches at or below water level. This tissue may 
have several functions as for buoyancy for weak, arching stems of Decodon 
verticillatus, for storage of oxygen or for insulation and protection. Development 
of aerenchyma has not been noted by us in any emergent monocot species, even 




Fig. 1: Nymphoides aquatica: a, leaf and cluster of flowers and spurlike roots 
on the petiole, x %; b, spurlike roots and young leaves separated from parent plant, 
X '/>; c, portion of leaf (under side) showing spongy tissue, greatly enlarged; d, im- 
malure ovary dissected from bud, x 8; e, flower, corolla spread out, x 4; f, petal, x 5; 
g, fruit, X 5; h, seed, x 20. (Courtesy of R. K. Godfrey). 



in the conspicuous Habenaria repens. It is commonly formed on species of 
Ludwigia, Aeschynomone, Ly thrum, Ammannia, Peplis and Sesbania. 

The organs and means of sexual reproduction in the vast majority of vascular 
hydrophytes are not unlike those of strictly terrestrial plants. Only a relatively 
few of our hydrophytes have wholly submerged hydrophilous flowers. Of these, 
those occurring in our region are Ceratophyllwn, Najas, Ruppia, Zannichellia, 
Posidonia, Cymodocea, Halophila, Thalassia, Halodule and several species of 
Callitriche. 

Besides sexual reproduction many hydrophytes have a capacity for vigorous 
vegetative reproduction, and this has been found to be exceptionally high in 
many genera. The means, however, of vegetative reproduction is apparently no 
different from those found in strictly terrestrial species. These include the capacity 
to regenerate from small vegetative fragments, especially if they have attached 
buds, and the production of tubers, rhizomes, stolons, turions, dormant apices 
and offsets. The ease of dispersal of these propagules by various agents, such as 
floods, waterfowl, animals, motorboat propellors, irrigation activities and the 
other direct actions of man account for the wide distribution of many aquatic 
plants. 

The stems, rhizomes, stolons, runners, petioles and peduncles of most sub- 
merged aquatic plants are notoriously brittle. Because of this brittleness even a 
slight disturbance, much less a violent one, will frequently cause fragmentation of 
the plant body. This is especially true of species in the genera Ceratophyllum, 
Egeria, Elodea, Myriophyllum and Najas. The same is also true to some extent 
for species of Callitriche, Azolla, Utricularia and in the Lemnaceae. Another 
method of vegetative reproduction is exhibited by Ceratopteris (Fig. 22), wherein 
plants, by means of gemmipary, arise from buds near vein-endings at the base of 
marginal notches in mature leaves. This method of vegetative reproduction is 
also common to some cruciferous species, such as in Armoracia, Cardamine and 
Rorippa. 

All types of rhizomes may be found in aquatic plants. These may be woody or 
herbaceous, spongy or firm, slender or enlarged, widely creeping or much-abbre- 
viated. Some species, especially in Cyperus, Potamogeton and Sagittaria produce 
stem tubers from which they perennate. These tubers, which are frequently near 
or just below the surface of mud, provide food for water fowl, especially geese. 

In Nymphoides (Fig. 1), the buried rootstock gives rise to long stems that 
trail through the water and gradually ascending to the surface to produce short- 
petioled leaves from their terminal nodes along with clusters of aerial flowers. A 
cluster of adventitious swollen, banana-shaped roots is produced from the node 
at the base of this floating rosette. Upon decay of the ascending stem the cluster 
of tuberous roots is set free and subsequently regenerates a new plant. 

Among those ordinarily dryland plants that apparently depend upon an excess 
of water during at least a part of their life-span are Heliotropium molle and H. 
glabriusculum, which grow where water temporarily accumulates after rains. These 
plants have evolved abundant corky tissue in their seeds that make them well- 
adapted for water dispersal. When observed during much of their life-span, how- 
ever, one might wonder why these species should be included in a work on aquatic 
and wetland plants for they grow in usually somewhat desertic situations. 

The principal agents that influence plant dispersal are water, animals, wind and 
man. Dispersal of strictly aquatic plants are undoubtedly influenced more by 
water and animals than by wind and man. Buoyant fruits and seeds, and vegeta- 
tive propagules broken from plants by turbulence may be carried great distances 
by currents and wave action. 

The transmission of vegetative fragments and seeds in the plumage and on the 
muddy feet of waterfowl undoubtedly accounts for the wide distribution of some 



fresh-water plants. Local distribution is further enhanced by the actions and 
activities of other types of animal life, such as amphibians, reptiles and small and 
large mammals. Seeds of some species that are eaten by various bird and animal 
life pass through their alimentary tract essentially unharmed. These are often 
dropped at some distance from their intake, thus adding to the distribution of the 
species. 

Our area lies in two of the flyways known to exist for migratory birds in North 
America. Arizona is in the Pacific Flyway while Texas, Oklahoma and New 
Mexico lie in the Central Flyway. Any kinds of water bodies found along these 
flyways are of importance to migratory birds for resting, feeding and protection. 
There is little doubt that north-south dissemination of some plant species occurs 
as a result of the activities of these migratory birds. 



III. Economics and Control of Aquatic and Wetland Vascular 
Plants 

Except for their aesthetic value in natural settings or as ornamentals, and their 
value to wildlife, strictly aquatic vascular plants, as such, have very little economic 
value in the modern-day world. They are, however, more or less involved in the 
general economics of such facets as wildlife, sports fishing, water utilization and 
weed control. Rice, which we consider to be a wetland or subaquatic plant, is 
undoubtedly the most important cereal plant grown by man. This plant would 
have to be an exception to the above statement. 

The ultimate goal to be obtained in the treatment or handling of vegetation in 
a water body depends upon the interest of the individual or organization con- 
cerned. Those interested in waterfowl and bird life, generally, would hope to 
maintain submerged and floating species of Potamogeton, Najas, Zannichellia and 
other important food plants of like nature as well as many of the erect emergent 
species, such as in Scirpus, Sparganium, Typha and Sagittaria. Those interested 
solely in fish and fish production might wish to exterminate aU plant life except 
plankton. And so it goes. 

Our making various statements in the text, such as this or that plant provides 
excellent protection for fish, does not imply that this is a good thing. It is merely 
a statement of fact or an observation. Perhaps the fish needs no protection or 
should not be protected! 

According to knowledgeable wildlife personnel the signficance of hydrophytic 
environments in relation to wildlife scarcely can be over-emphasized, and studies 
such as this that will lead to a better knowledge of the kinds and distribution of 
plants of aquatic and wetland habitats are of great interest and usefulness to all 
personnel involved in wildlife management. For instance, wildlife management 
personnel will want to know the identity of the plants under which waterfowl, fish, 
mammals, invertebrates, and other inhabitants of marsh and aquatic habitats feed 
and use for nesting and resting sites, coverage and protection. Also, wildlife 
personnel need to know the plant species to help them better assess a particular 
area in regard to the types and abundance of plant foods present and to be able 
to create conditions that will control and improve the food supply. A similar need 
is present for the health engineer, who, for instance, may want to know the 
identity of the plants that are associated with the breeding grounds of such pests 
and disease-carriers as mosquitoes, and for the hydrologist who needs to know 
what plants contribute to water-pollution and -contamination, and those that 
contribute to its clarification and potability. 

10 



Many species of plants have a beneficial effect upon water in contrast to those 
that have a deleterious effect. For instance, it is realized that depletion of vegeta- 
tion with accelerated stream-channel erosion decreases or entirely prevents fish 
production through the reduction of available food and cover, the increasing of 
water temperatures, and through sedimentation of spawning beds. To maintain a 
continuity of fish and wildlife, generally, it is essential to know how to maintain 
their habitat and to determine the biological requirements and relationship of 
each species, especially in regard to cover and food for its normal growth. 

Another function of plant life in relation to water is its restraining action upon 
rapidly moving streams so as to prevent excessive erosion of their banks. Only 
those species that can tolerate having their roots submerged or that can grow in 
saturated soils can survive on the margins of streams and lakes. Without such 
species to exert control there would be no limit to the amount of erosion that 
might occur. The knowledge to be gained from the study of aquatic and wetland 
vegetation can thus be directed to the control of channel- and bank-erosion to 
improve fish habitats and their food supply. 

In 1970, Boyd published a paper in which he pointed out the apparent poten- 
tial of using aquatic angiosperms for the wholesale removal of nutrients from 
effluents and natural waters. He further suggested that because of their food 
qualities aquatic angiosperms could be harvested, dried and used as a feedstuff. 

Boyd found that the most suitable species for possible nutrient removal from 
water were water hyacinth {Eichhornia crassipes), alligator weed (Alternanthera 
philoxeroides) , water willow (Justicia americana) and cat-tail (Typha ladfolia). 
All of these plants could be harvested by relatively simple means and they had a 
relatively high nutritive value for use as feedstuff. A series of small holding ponds 
into which effluents would be directed and in which plants would be grown for 
nutrient removal were thought to be more satisfactory than just one large body 
of water. 

There are problems in this proposed use of these aggressive aquatic angio- 
sperms, foremost of which is the fact that, with the possible exception of Justicia 
americana, they can become pernicious weeds. 

It is entirely possible that with more research man will be able to manipulate 
native vegetation, even more than he does at present, for his welfare. The most 
obvious and a long-standing practice has been the use of plants in erosion control. 
There are many and various uses that might be made of aquatic angiosperms. 

There are numerous troublesome aquatic weeds throughout the world, and 
there is no question whatsoever about the necessity to control the rampant growth 
of many of these noxious vascular hydrophytes. The main question revolves around 
how this should be done. Anyone who has seen a waterway that was once open 
and clear but is now essentially dessicated and clogged by water-hyacinth {Eich- 
hornia crassipes) or alligator weed {Alternanthera philoxeroides) must realize 
that such is a situation that should and must be corrected. 

An improper balance of the flora and fauna, frequently caused by the undue 
aggressiveness of such plants as Alternanthera and Eichhornia, can result in pollu- 
tion and/or stagnation. Observations on the tolerance and aggressiveness of indi- 
vidual species must be undertaken so as to understand better why some species are 
limited in distribution while others are widely distributed. A detailed study of 
the reproduction by seeds and vegetative means of some hitherto neglected species 
will supplement that which is already known about other species. Mobility, aggres- 
siveness, and various methods of distribution, such as the requirements needed for 
dissemination, and the viability of seeds under different conditions should be 
studied so as to better understand some of the yet unanswered problems of the 
specialized adaptation of these plants to their environment. 

11 



With identification of species in a particular plant community, it will be possible 
to determine their optimum needs to attain their best growth and reproductive 
capacity, or likewise through investigation and research find some means for their 
control that could be recommended elsewhere. Without the identity of these 
organisms it would be impossible to accomplish this work. 

Various methods have been used to control aquatic weeds, but undoubtedly 
the most efficacious though potentially dangerous to the world's life is the use 
of the many various herbicides. The use of herbicides in the elimination of nuisance 
aquatic angiosperms occasionally kill fish and desirable organisms. The decay 
of dead plants, too, can deplete the dissolved oxygen to the extent of killing all 
aerobic organisms. Often, also, the destruction of one nuisance organism only 
makes room for invasion of another equally noxious organism. 

The oldest method of combatting aquatic weeds is that of manual and mechani- 
cal control. This is still practiced, especially where small bodies of water and 
streamways are involved. These methods include cutting and harvesting the plants 
by hand, draining and drying out plus bulldozing the water areas to be cleaned, 
mechanically mowing with cutters along banks or attached to boats, and dragging 
and dredging the area to be cleaned. In line with these mechanical methods, on 
Caddo Lake in northeastern Texas an unsuccessful, or rather unprofitable, attempt 
was made to mechanically harvest the tremendous overgrowth of water plants and 
to use the dried processed plants as peat or as a soil conditioner. If this activity 
had been successful this would have been a direct economic way to control aquatic 
weeds. 

The most idyllic type of aquatic weed control would be biological. Each noxious 
species, however, would necessitate an individual study to discover in what way it 
might be controlled — either parasitically by a fungus or insect, or by aquatic 
herbivores such as certain African and Chinese fish. TTie manatee or sea cow 
is the classic example of an aquatic herbivore in that it can consume huge amounts 
of rooting and floating vegetation. Thus far, however, it has proved impractical or 
biologically impossible to manipulate the manatee as a trained grazer. 

IV. Pollution in Aquatic and Wetland Habitats. 

Certainly there are no greater problems facing our civilization today than 
those of contending with water and air pollution. Everything that we can learn 
that will help us ultimately to manage these problems will be to our advantage. 
It is hoped that the results of this research will provide us with some phase of 
knowledge that will help us in combatting the corrosive situation of water pollu- 
tion. 

As has been noted in our Preface, from the very beginning of this research 
consideration of the environment has had an overwhelming influence upon our 
interpretation of what plants were to be included in this work. This consideration 
was long in progress before "environment" and "ecology" became household words 
in the United States. This consideration of the environment was guided mainly by 
our initial interest in this project: water as a critical resource in southwestern 
United States. Since this resource is so critical in this part of the country, and 
it will doubtless become more so with time, we thought that a knowledge of the 
plants that are associated with water should be made available to everyone who 
might be concerned with this vital commodity. We also hoped that our work would 
encourage more appreciation for water as a vital resource and thus create more 
respect for and a greater care of this rapidly vanishing and very necessary asset. 

Perhaps one of the most frustrating phases of this project was our not being 
able to find areas that we could consider as "controls" for each of the ecosystems 



that we expected to observe and study during various seasons and over a period 
of several years. Because of man's omnipresent interference with everything 
natural, no lake, pond, river, marsh, bog or swamp could be designated as having 
never been disturbed or the way Mother Nature would have wanted it without 
man's disturbing and polluting influence. We early forewent the idea of establish- 
ing "controls," and decided, instead, to accept conditions as we found them to 
exist. We realized that pollution had become so thoroughly spread, and it had 
unquestionably affected or so changed the various ecosystems that it would be 
impossible to determine what species comprised the original vegetation of most 
of the area studied. 

We have tried to summarize below the primary water pollutants and to point 
out some of the deliterious effects of their pollution upon the environment. These 
data are a combination of personal observations and those taken from numerous 
articles, papers and books that have been published on the subject during the last 
few years, but primarily from an article by Young (1970). 

Doubtlessly, the chief causes of water pollution are inadequately treated sewage 
and manufacturing wastes, oil from ships and drilling leaks, fertilizer runoff, 
pesticide residues and acid drainage from mines. These wastes, plus sediment, have 
ruined practically every major river in the Nation, and have converted them from 
what was once unadulterated assets to the Nation into liabilities and a real menace 
to much of the world's population. The pollutants they transport to the sea are 
endangering our estuaries, wetlands and coastal waters — nurseries for most of our 
commercially important fish and shellfish. 

Though chemical fertilizers have greatly increased crop production, and long- 
lasting pesticides have achieved their goal in protecting our crops, wind and rain 
have carried these pollutants into our rivers, lakes and ponds where the fertilizer, 
plus sewage, has contributed to an enormous overgrowth of algae. This over- 
growth of algae in the upper zone suffocates the lower layers of algae by depriving 
them of light for photosynthesis. This lower layer dies and decays, and in doing 
so uses oxygen that is needed by fish which, in turn, die. The pesticides, upon 
reaching the oceans, are carried up the food chain through fish to thwart the 
reproduction of eagles, ospreys, pelicans and other fish-eating birds. 

Mercury waste has been flushed into many lakes and rivers by industry. Bacteria 
convert some of it into highly toxic methyl mercury, which is passed along the 
food chain into fish, such as sword and tuna, that man now can not eat with 
knowledge of absolute impunity. Various mercury compounds used in agriculture 
are known to have poisoned game birds in many parts of the world. 

Stripping the forests for lumber, excessively wide highways and our paralytic 
housing developments encourage soil erosion and the steady erosion of one of our 
major sources of oxygen-producing greenery, while strip-mining scars the country- 
side and allows mine acids to wash and spread out to kill adjacent and surrounding 
vegetation. 

Our rapidly increasing nuclear power plants create thermal pollution in the 
water used for cooling. The heated water holds less oxygen and can thus disrupt 
the life cycle of aquatic organisms. 

Oil spills foul beaches throughout the world, as can be attested by anyone who 
has walked along practically any of our beaches during the last several years. 
The blotches of black oil that accumulate on the bottom of feet is only a harmless 
visual pollutant compared to the toxic chemicals released that can kill fish and 
birds, and, by forming a film over the water, oil can inhibit the intake of oxygen 
by the water to smother life on the bottom. Millions of tons of petroleum each 
year are flushed from ships, spilled at fueling ports, and poured into the sea 
from leaking or runaway offshore wells and wrecked tankers. 

13 



The sad fact is that we not only continue to pour these wastes into our environ- 
ment but we also continue to add new herbicidal and pesticidal chemicals without 
their being properly tested to learn what long-range effects they will have upon life 
on our planet. 

Sculthorpe, in 1967, has the following to say about the use of herbicides in 
England: "The toxity of numerous herbicides necessitates stringent precautions 
for their use in aquatic habitats. It is an appalling and terrifying truth that all 
too many aquatic herbicides have come into general use despite colossal ignorance 
of their toxicology and biological side-effects. Although the situation is not perhaps 
quite as devastating as that created by the indiscriminate use of certain insecticides 
in the U.S.A. and Europe, it is nevertheless deplorable. The principal dangers 
inherent in the use of toxic herbicides for eradicating aquatic weeds are: (a) the 
hazard, to the persons applying the chemical or to others in the vicinity, of oral 
intake or cutaneous absorption; (b) the contamination of domestic water supplies; 
(c) the poisoning of plankton, invertebrates, fish and animals living in or around 
the water; and (d) the contamination of surrounding land bearing sensitive food 
crops or grazing livestock." 

A useful bibliography of work on the harmful effects of herbicides and insecti- 
cides on aquatic life has been compiled by Ingram and Tarzwell (1954). There is 
no doubt that this bibliography could be greatly augmented if a revision were 
published today. 

We have found literally appalling situations where herbicides of any and all 
types are indiscriminately dumped directly into lakes, fish ponds and stock tanks. 
We learned that in many such instances a fast-talking herbicide salesman was 
usually dealing with a customer who was grossly uninformed, misinformed or 
just totally ignorant of the possible damage that might be done to his water body. 
Most customers could not even remember the name of the herbicide they used nor 
its composition. They were merely assured by the glib salesman that "it" would 
"kill" all plant life. Many sadly learned that "it" often also contributed to the 
killing of their fish and possibly every other form of animal and plant life with 
which "it" came in contact. 

In line with the indiscriminate direct and indirect dumping of chemicals into 
our water bodies, we have often wondered what the eventual effect will be upon 
man who persists in catching and eating those fish that "got away" from the 
potentially deadly concentration of chemicals. Though we have asked this question 
of many learned individuals none profess to know what may be the eventual long- 
range effect upon man. They seem to think it is too soon to know the answer. 
Meanwhile, man may be literally eating himself into oblivion. 

We have noted with dismay the perversion of some of our state as well as 
national wildlife refuges from their original intent and purpose to preserve and 
protect every aspect of nature and wildlife to the dictum of making available 
to pillaging and irresponsible man facilities for his abuse at the expense of all 
else. The prevailing philosophy of certain personnel that are responsible for the 
management of wildlife preserves was dramatically demonstrated to us in 1968. 
In 1967 we had examined the plant-life in several of the then beautiful lakes in 
one of the fine national reservations in our area with the thought of continuing 
over a several-year period the study of some ecological phases of our project. 
Imagine our chagrin and disappointment when we returned in 1968 to find that 
all of the lakes we were planning to study had only very recently been treated 
with a potent herbicide — nothing but rotting plant remains with a few small 
mammals floating here and there were to be found in and about the edges of 
these once very beautiful and biologically balanced lakes. The chemical stench in 
the air only added to our extreme displeasure. As taxpayers, we were angry and 
appalled that a total disregard for the wildlife of these lakes should be so blatantly 

14 



displayed by so-called responsible administrators of the Nation's resources. The 
superintendent explained to us that the destruction of all aquatic plant life, irre- 
spective of the long-range ill-effect it would have on the lakes, was necessary so 
that people who wanted to swim in the lakes would not risk being entangled in 
the underwater growth! We wondered — what is the need of setting aside a "wild- 
life refuge" if its main purpose is to be prostituted! 

For decades we have blindly swept our filth beneath the surface of our waters, 
and just as blindly we have assumed that it would remain well hidden under 
the "rug." Until rather recently the best of authorities have assumed that sewage 
and garbage that we have assigned to the depths of our lakes and oceans would be 
like the proverbial sleeping dog. It is now known, however, that even at the 
greatest depths some turbulence occurs, and we learn that our "sleeping dogs" 
have never lain placidly; they are now coming home to haunt us in the form of 
poison fish and dying wildlife. In view of the fact that ocean currents have been 
known for such a long time the assumption that no such phenomena would occur 
in inland coastal waters seems strange. 

The debris left in lowlands and forests that border lakes and rivers after high 
water is astronomical. In some such areas we have traversed it was literally impos- 
sible for us to take a step without stepping upon some sort of extraneous object 
such as the ubiquitous bottles and cans, plastic containers, old tires, shoes and 
every other type of rubbish. These had not only recently been water pollutants but 
now they were deposited on land where they had become visual pollutants. 

It may be of interest to others that our experience from the very beginning 
of this project has been one of frustration. We have felt, and at times been treated, 
like interlopers because of our interest in and desire to work on the biological, 
particularly botanical, aspects of aquatic pollution. We have found that most 
research funds for pollution and water quality research have largely been taken 
over by inorganic scientists, primarily chemically trained and oriented, most of 
whom either have no interest in nor feeling for biological research. We would have 
greatly appreciated the opportunity to work with a team of scientists on a bio- 
logical approach to our various problems involving aquatic pollution. 

We can only say "amen" to Sculthorpe's statement on page 28 (1967): "Pollu- 
tion by sewage and other domestic products, poisonous industrial effluents, pesti- 
cides and radioactive wastes has been steadily increasing and must now be treated 
as an integral feature of the aquatic environment. So far, it has been treated 
principally, indeed too often exclusively, as a physiochemical phenomenon. Its 
biological, and particularly botanical, consequences have been much neglected." 

It has been said by some wise individual that the environment is almost as 
much a product of the community as the community is of the environment. This 
might be carried a step further to say that the condition of the environment is a 
realistic measure of the kind of civilization that exists to inhabit that environ- 
ment. 



15 



KEY TO H0NOC0TYLEDON6 AND DICOTYLEDONS 



FLOWERS WITH PARTS USUALLY IN 
MULTIPLES OF 3 (RARELY NORE OR LESS) 

LEAVES USUALLY PARALLEL VEINED 
(RARELY NET VEINED) 

VASCULAR BUNDLES DISTINCT AND 
SCATTERED 

COTYLEDONS 1 

nONOCOTYLEDONEAE 



SOME FLOWER TYPES 




FLOWERS WITH PARTS USUALLY IN 
MULTIPLES OF 2, 5 OR MANY (RARELY 5) 

LEAVES PINNATELY OR PALMATELY 
VEINED (RARELY PARALLEL VEINED OR 
RIBBED) 

VASCULAR BUNDLES OF STEMS 
USUALLY IN A RING (SCATTERED 
IN A FEW AQUATICS) 

COTYLEDONS 2 (RARELY REDUCED 
TO 1 IN A VERY FEW AQUATICS) 

DICOTYLEDONEAE 



SOME FLOWER TYPES 




Fig. 2: Illustrated key to monocotyledons and dicotyledons. (From Mason, Fig. 1). 



Artificial Analytical Key to the Higher Taxa 
of Aquatic and Wetland Vascular Plants 



Key to the Major Groups 

1. Rushlike, fernlike, mosslike or quill-leaved plants without true seeds or flowers, 
reproducing chiefly by spores I. Pteridophyta, p. 17 

1. Habit various; plants producing seeds (2) 

2(1). Plants producing seeds but not true flowers, i.e., either having "cones" 
(with seeds borne more or less exposed on the upper surfaces of 
the scales of the cones) or fleshy structures with the basic struc- 
tures of cones (as juniper "berries"), or cones with only a few thin 
scales (as in Ephedraceae) II. Gymnospennae, p. 19 

2. Plants producing true flowers, i.e., the seeds borne enclosed in specialized 

structures (ovaries) (Angiospermae) (3) 

3(2). Plants with several if not all of the following characters: vascular bundles 
scattered in the usually solid internodes (these bundles can be seen 
as scattered dots in the stem-transection) ; cotyledon (seed leaf) 
solitary; when flower parts in whorls then some in whorls of 3, at 
least not in whorls of 5 parts; leaves parallel-veined; root system 
fibrous (i.e., most roots adventitious); plants nearly always herba- 
ceous III. Monocotyledoneae, p. 19 

3. Plants with several if not all of the following characters: vascular bundles of 

young stems forming an interrupted cylinder (seen as a ring of dots 
in stem-transection); cotyledons usuaUy 2, rarely more or one; 
flower parts (when in whorls) often in 4's or 5's, less often in 3's, 
2's, 6's, etc.; leaves usually reticulate-veined; roots either fibrous or 
not; plants herbaceous or woody, the wood forming concentric 
layers when present; young stems nearly always hollow or with a 
pithy zone in the center.; IV. Dicotyledoneae, p. 23 



I. Pteridophyta (p. 37 of text) 

1. Foliage leaves scalelike or long-subulate, sometimes united into toothed 
sheaths (2) 

1. Foliage leaves or entire frond with broad or narrow, entire, toothed, pinnate, 

pinnatifid or variously dissected blades (6) 

2(1). Stems hollow, fluted, jointed; sporangia borne under peltate scales in a 
cone 5. Equisetaceae, p. 45 

2. Stems solid, not fluted or jointed; sporangia borne in the axils of scalelike or 

small leaflike or long-subulate bracts (3) 

3(2). Leaves rushlike, long-subulate, more than 3 cm. long, borne in a tuft on a 
short cormlike stem 4. Isoetaceae, p. 41 

3. Leaves scalelike, flat, sometimes concave or cymbiform, less than 3 cm. long, 

borne on erect or creeping elongate stems and branches (4) 

17 



y REGULAR 
PERIANTH 



SEGMENTS 
UNITED 
AT THE BASE 




THE HAJOR GROUPS Of tlONOCOTYLLDONS 



WHORLED OR 
OPPOSITE LEAVES 

OVARY INFERIOR 




EQUITANT LEAVES 



OVARY 5UPERI0R 




PISTILS MORE 
THAN ONE 

PERIANTH OF 
TWO SERIES 




FLOWERS 

CROWDED ON 

5PADIX 



STIGMA- 



PETIOLE 
INFLATED 



PERIANTH PRESENT 





PERIANTH 
ATTACHED 
OVARY TO STAMEN 

SUPERIOR FILAMENT 



PERIANTH 
DRY AND 
PAPERY 



SPATHE 



PERIANTH ABSENT OR REDUCED TO BRISTLES OR SCALES, SOHET I I1E5 FLOWERS IN A PERIANTH-LIKE 

FRUIT FLOWER f^") \\i\ a ^ UMBEL INVOLUCRE 





LEAFLESS 
PLANTS (I 

STAMINATE 
FLOWER 

PISTILLATE 
FLOWER 

FLOATING OR SUBriERSLD AQUATICS 




FLOWERS IN 
LEAF AXILS 



FLOWERS IN 
FLATTENED SPIKE 



TERRESTRIAL OR, IE AQUATIC, ONLY BASE OF PLANT IN WATER 

STAMINATE 
FLOWERS ^\JS?St 

BLftDE 

lligule- 



PALEA 




FLOWERS IN 
MEADS OR 

HEAD- LIKE pt«,ANTH 

WHORLS OF bRISTLES 



FLOWERS IN 
AXILS OF 
DRY CHAFFY 
BRACTS 



Fig. 3A: The major groups of monocotyledons. (From Mason, Fig. 2). 



4(3). Plants often forming broomlike clumps; stem naked except for distantly 
placed minute scalelike leaves; sporangia subtended by 2 minute 

scale leaves and scattered on upper part of branches 

1 . Psilotaceae, p. 37 

4. Plants not in broomlike clumps; stem with closely placed or imbricated leaves; 

sporophylls not bifid, borne in cones (5) 

5(4). Plants with erect fruiting stems; cones cylindric; spores of 1 kind 

2. Lycopodiaceae, p. 39 

5. Plants with ascending or spreading fruiting branches; cones more or less 

quadrangular; spores of 2 kinds 3. Selaginellaceae, p. 41 

6(1). Plants usually large and conspicuous, growing in soil or on rocks or trees, 
or (if free-floating or submerged) large and dendroid; spores of 1 
kind, minute (7) 

6. Plants small, free-floating or partially submerged or rooted in mud; spores of 

2 kinds, borne in sporocarps (10) 

7(6). Fertile fronds with 2 distinct parts, the fertile part being in the form of 
a spike or panicle and arising from the petioles, the sterile part of 

the frond being either entire or pinnately dissected 

6. Ophioglossaceae, p, 47 

7. Fronds not as in Ophioglossaceae (8) 

8(7). Sporangia in panicles or (sometimes fingerlike) spikes developed from the 
modified blade or parts of the blade 7. Osmundaceae, p. 51 

8. Sporangia borne on the back of (the lower side of) or on the margin of the 

blade (9) 

9(8). Plants never free-floating nor dendroid; sporangia usually long-stalked 

10. Polypodiaceae, p. 61 

9. Plants usually free-floating or very rarely deeply submerged, the sterile leaves 

forming a floating sterile rosette; sporangia sessile or nearly so 

1 1. Parkeriaceae, p. 77 

10(6). Plants rooting in mud or on muddy bottoms; rootstocks creeping; leaves 

quadrifoliolate or filiform, not imbricate nor matted, distant 

8. Marsileaceae, p. 53 

10. Plants free-floating or resting on mud; rootstocks pinnately branched; leaves 

deeply 2-lobed, imbricaite, matted 9. Salviniaceae, p. 57 



II. Gymnospermae (p. 79 of text) 

Leaves spreading in 2 ranks, usually seasonally deciduous; cones globose; cone 
scales club-shaped, without distinct bracts, flat or peltate, with two 
3-angled or somewhat 3-winged seeds 12. Taxodiaceae, p. 79 



III. Monocotyledoneae (p. 85 of text) 

1. Plants 1 cm. long or usualy less, thalluslike, stemless, usually floating or 
resting on mud or some type of extraneous matter such as leaves 
and pieces of wood 28. Lemnaceae, p. 563 

1. Plants usually larger, not with above combination of characters (2) 

19 



2(1). Each pistillate flower with 4 free carpels each of which at fruiting time is 

long-stipitate; submerged aquatics with linear leaves 

17. Ruppiaceae, p. 123 

2. Carpels either coalescent or if free then not stipitate (3) 

3(2). Carpels 2 to numerous, free from each other (4) 

3. Carpels solitary or if more than 1 then these (at base or throughout) coalescent 

for more than a third their length (7) 

4(3). Carpels numerous per female flower 21. Alismataceae, p. 133 

4. Carpels 2 to 9 per flower (5) 

5(4). Ovules numerous; flowers showy, yellow 22. Butomaceae, p. 153 

5. Ovules solitary; flowers inconspicuous (6) 

6(5). Perianth of 4 free rounded shortly clawed valvate segments 1-4 mm. long 
15. Potamogetonaceae, p. 95 

6. Perianth absent (genus Zannichellia of) 16. Zannichelliaceae, p. 117 

7(3). Ovary inferior; perianth clearly epigynous (8) 

7. Ovary superior or apparently so, in some taxa the perianth reduced or absent, 

in some the perianth adnate to the ovary for a very short distance 
basally (14) 

8(7). Partly or wholly submerged plants; ovules numerous, spread all over the 

inner surface of the carpels or on the intrusive septa 

23. Hydrocharitaceae , p. 156 

8. Plants not submerged or if partly so the ovules confined to placentary areas 

(9) 

9(8). At least the inner 3 tepals dissimilar to one another, the flower thus not 
radially symmetrical (10) 

9. At least the inner 3 tepals (and usually the outer one, too) equal to each 

other or nearly so, the flower thus approaching true radial sym- 
metry (12) 

10(9). Ovule solitary in each cell 39. Marantaceae, p. 686 

10. Ovules more numerous (11) 

1 l( 10). Flowers only slightly zygomorphic, reddish or orange, in terminal thyrses 
on erect stems to 12 dm. tall 38. Cannaceae. p. 684 

11. Flowers strongly zygomorphic, the lower (or rarely uppermost) of the 3 

inner tepals strikingly diff"erent from the other 2, forming a label- 
lum; stems usually less than 5 dm. long 41. Orchidaceae, p. 690 

12(9). Leaves equitant, distichous and folded along the midrib; stamens 3 

37. Iridaceae, p. 673 

12. Leaves not equitant: stamens 3 or 6 (13) 

13(12). Stamens 3; basal leaves usually linear and grasslike and stem or scape 
leaves scalelike 40. Burmanniaceae, p. 686 

13. Stamens usually 6; basal leaves usually broader; plants very diverse in habit.... 

36. Ainaryllidciceae, p. 664 

14(7). Palmlikc plants with perennial stem 5-70 cm. thick at ground level and 
lanlike leaves 4-12 dm. broad 26. Palinae, p. 555 

14. Habit otherwise ( 15) 

20 



15(14). Submerged plants mainly of salt-water gulfs and bays, occasionally 
inland in brackish or fresh-water (16) 

15. Plants terrestrial or (if in water) at least partly or wholly emersed (18) 

16(15). Plants perennial, entirely marine; leaves strap-shaped, leathery, at least 
5 mm. wide, essentially entire; rhizome and stem thick and woody, 
the rhizome with persistent fibers from the nodes, the stem adorned 

with the persistent fibrous leaf bases; flowers spicate 

19. Posidoniaceae, p. 129 

16. Plants of fresh, brackish or salt-water; leaves linear, entire or toothed; 

rhizome and stem not thick and woody, not provided with fibers or 
persistent fibrous leaf bases; flowers axillary, solitary or cymose (17) 

17(16). Carpels 2 or more, rarely solitary; ovule pendulous; perennials 

16. Zannichelliaceae , p. 1 17 

17. Carpels solitary; ovule basal, erect; annuals 18. Najadaceae, p. 123 

18(15). Flowers ebracteate; small herbs with narrow grasslike basal leaves and 

slender spikelike racemes of small usually greenish flowers 

20. Juncaginaceae, p. 129 

18. Flowers with bracts, bractlets, scales or glumes (19) 

19(18). Proper perianth absent or nearly so, the flowers borne in dense heads, 
spikes or racemes or thickly crowded on a fleshy axis or else vari- 
ously disposed in panicles, when genitalia subtended by scalelike 
structures these never numbering precisely 3 in 1 series or 6 in 2 
series (20) 

19. Proper perianth present, often in 2 series of 3 members each (in some 

families the outer or inner or both series scalelike (25) 

20(19). Flowers crowded on a terminal elongate fleshy axis which below the 
flowering zone usually has a large foliaceous partially or wholly 
sheathing bract (spathe) which covers the inflorescence during its 
early development..... 27. Araceae, p. 556 

20. Axis of inflorescence not fleshy; bract (if present) not so large and not cover- 

ing the young inflorescence (21) 

21(20). Inflorescence a series of globose heads at the upper nodes, the uppermost 

heads of staminate flowers, the lower ones of pistillate flowers 

14. Sparganiaceae, p. 89 

21. Inflorescence otherwise (22) 

22(21). Inflorescence solitary, terminal, globose or hemispheric, 2-15 mm. thick, 
exceedingly dense, not subtended by large bracts (bracts only 1-4 
mm. long) 31. Eriocaulaceae, p. 588 

22. Inflorescences not globose nor hemispheric or if so (as in some Cyperaceae) 

then closely subtended by several bracts several times as long as the 
inflorescence is thick (23) 

23(22). Inflorescence a very dense brownish spike 12-40 cm. long and 1-2 cm. 
thick with thousands of minute flowers, the male above, the female 
below; "cat-tails" 13. Typhaceae, p. 85 

23. Inflorescence otherwise (24) 

24(23). Leaves distichous (and sometimes equitant); with rare exceptions each 
floret subtended by 2 scales (the lower or lemma abaxial and with 
1 midvein; the upper or palea adaxial and with 2 unequal non- 
medial nerves) 24. Gramineae, p. 169 

21 




THE MAJOR GROUPS Of DICOTYLEDONS 




PERIANTH 

SEGMENTS ALL 

PETAL -LIKE 



FLOWERS 
IN HEAD-LIKE 
CLUSTERS 




FLOWtRS 
MONOECIOUS 

PLANT5 WOODY AT BA5L (TRELS.6tiRU6S. OR VINE5) 



SEED UlTH 
LONG HAIRS 



PERIANTH 
SEGMENTS ALL 
SEPAL -LIKE 



STYLE 
STAMENS \jl 



PETALS 
UNITED INTO 
A TUBE 

FLOWERS IN 
INVOLUCRAL PAIRS 

PISTILS MORE 
THAN ONE 

PETALS 
FREE 
FROM ONE 
ANOTHER „, 

PERIANTH DIFFERENTIATED OVARY 

INTO PETALS AND SEPALS INFERIOR 




PLANTS WhOLLY HERBACEOUS 



COROLLA AND 
CALYX ABSENT 



FRUIT A 4-CELLED 

MANY-SEEDED 

CAPSULE 




COROLLA ABSENT 

CALYX PRESENT 



ONE 
SEEDED 

FRUIT DEHISCENT 
C1RCUM5CISSILE LONGITUDINAL 



LEAVES DISSECTED 



COROLLA ABSENT.CALYX PRESENT OR AB5ENT 



FLOWERS \N STOUT 
SPIKE, SUBTENDED BY 
WHITE PETALOID BRACTS 



COROLLA PRESENT 




FLOWERS 
REGULAR 
PETALS FREE 
FROM ONE ANOTHER 
FLOWERS HYPOGENOUS 





STAMENS 
UNITED 



FLOWERS 
CRUCIFEROUS 



PISTILS NUMEROUS 
ON ELONGATE 
RECEPTACLE 



FLOWERS IRREGULAR, 
PAPILIONACEOUS 



LEAVES 
PITCHER-SHAPED 





PETALS FREE EROH ONE ANOTHER 



STYLES STYLE I 
2 TO 5 STIGMAS 3 



FRUIT FIVE 
GLOBOSE 
CARPELS 



FRUIT 

SPLITTING 

INTO 2 ONE- 

SEEDED CftRPELS 



PETALS UNITED 




STIGMA 

ANTHER / 
COLUMN 




FRUIT OF 

TWO TO FOUR 

NUTLETS 



STAMENS 
UNITED INTO A 
TUBE AROUND 
THE STYLE 



COROLLA IRREGULAR 



Fig. 3B: The major groups of dicotyledons. (From Mason, Fig. 3). 



24. Leaves tristichous; each floret subtended by a single abaxial scale (seemingly 

2 scales in Hemicarpha, or by a sac in Carex, or by bristles in addi- 
tion to the scale in some genera) 25. Cyperaceae, p. 341 

25(19). Calyx irregular, glumaceous, the 2 persistent lateral sepals cymbiform 
and dorsally keeled or winged, the third sepal larger, obovate and 
enfolding or forming a hood over the corolla in bud and deciduous 
with it 30. Xyridaceae, p. 578 

25. Calyx otherwise (26) 

26(25). The 3 inner tepals (petals) quite distinct in color and/ or texture from 
the 3 outer ones (sepals) (27) 

26. The 6 tepals all rather similar in color and texture, either all dry and scale- 

like or all corolline (28) 

27(26). Ovary completely 3-celled; lower part of leaves sheathing the internodes 
32. Commelinaceae, p. 593 

27. Ovary incompletely 3-celled or 1-celled; leaves not sheathing 

29. Mayacaceae, p. 578 

28(26). Perianth of 6 scalelike dry brown noncorolline tepals 

34. Juncaceae, p. 604 

28. Perianth of 6 corolline tepals or with 6 corolline segments (29) 

29(28). Usually floating, partly submerged or at least rooting in mud; inflores- 
cence subtended by spathelike leaf sheaths; seeds usually ribbed; 
flowers usually somewhat zygomorphic....33. Pontederiaceae, p. 597 

29. Dryland to marshland plants; inflorescence usually not subtended by a 

spathelike leaf sheath; seeds various, usually not ribbed; flowers 
almost always radially symmetrical 35. Liliaceae, p. 646 



IV. Dicotyledoneae (p. 734 of text) 

1. Flowers with all the petals united at their edges (at least near the base) into 
a single structure, this corolla often deciduous as a unit and often 
shaped like a saucer, a cup or a trumpet (2) 

1. Flowers not as above, if any petals joined then not all of them involved or 

else not joined at their edges (occasionally the petals may seem 
to be joined somewhat in bud but not in the mature flower), or 
petals absent (48) 

2(1). Flowers epigynous or partly so, i.e., the perianth and stamens when pres- 
ent appearing to be attached to the top or near the middle of the 
sides of the ovary (3) 

2. Flowers hypogynous or perigynous, the sides of the ovary free from the peri- 

anth or the floral cup, the perianth attached below the ovary (12) 

3(2). Anthers 5 or 4, coalescent but filaments free (anthers exceptionally free 
in the genera Ambrosia, Xanthium, Iva); fruit an achene and usu- 
ally crowned by the modified calyx of bristles or scales; style 
branches usually 2, usually divergent; flowers usually very small 
and aggregated in involute heads 129. Compositae, p. 1586 

3. Anthers usually free (exceptions: Curcurbitaceae; 1 genus of Campanulaceae); 

fruit diverse but rarely an achene (exception: Valerianaceae); style 
branches 1 to 20; flowers rarely aggregated in involucrate heads (4) 

23 



4(3). Stems trailing or twining, often vinelike, often scabrous, often with lobed 
leaves; fruits with a leathery or tougher rind and fleshy placental 
tissue inside and numerous flattish seeds either buried in flesh (as 
in the watermelon) or in 2 to many longitudinal rows on the sev- 
eral (3 to 5, usually) placentas which are on the walls of the 

chamber (as in pumpkins and gourds); stamens often united 

127. Cucurbitaceae, p. 1569 

4. Plants not with the cucurbitaceous character-combination (5) 

5(4). Anthers 8 or more (6) 

5. Anthers 5 or fewer (rarely 6 in Ericaceae) (8) 

6(5). Stamens numerous, a cluster of them present at the base of each petal 

105. Symplocaceae, p. 1301 

6. Stamens 8 to 16 (7) 

7(6). Leaves and branchlets nearly glabrous, at least never with stellate or lepi- 
dote vestiture; fruit a many-seeded berry; anthers appendaged 
(genus Vaccinium of) 101. Ericaceae, p. 1267 

7. Leaves and branchlets with at least some stellate or lepidote vestiture; fruit 

winged or few-seeded, round and dry; anthers unappendaged 

104. Styracaceae, p. 1296 

8(5). Placenta free, central, attached to base of locule (genus Samolus of) 

102. Primulaceae, p. 1276 

8. Placenta when axile not free from the sides (in a few taxa the placenta is 

apical) (9) 

9(8). Leaves alternate 128. Campanulaceae, p. 1571 

9. Leaves opposite or whorled ( 10) 

10(9). Fruit an achene or an achenelike structure or at least indehiscent and 
with a single maturing ovule 126. Valerianaceae. p. 1562 

10. Fruit a capsule, berry, drupe or schizocarp (11) 

11(10). Stipules present (these sometimes in the form of leaflike structures 

which add to the number of "leaves" at a node) 

124. Rubiaceae, p. 1538 

H. Stipules absent but stipular lines sometimes evident 

125. Caprifoliaceae, p. 1555 

12(2). Corolla forming a cap over the tiny flower' and falling as a unit at the 
onset of anthesis, the petals separating from each other only at the 
base; stamens opposite petals but not attached to the corolla, per- 
sistent after the corolla falls (genus Vitis of). ...86. Vitaceae, p. 1 108 

12. Corolla not behaving as in grape flowers (13) 

13(12). Gynoecium at anthesis or shortly before anthesis with a 2-Iobed ovary 
(or appearing as 2 carpels or 2 ovaries) but only a single style 
owing to fusion of the styles above the ovary lobes; 1 or each lobe 
of the ovary maturing into a folliclelike structure; stigma massive 
(14) 

13. Ovary entire or if deeply 2-lobed then styles not united or if so the single 

style gynobasic; stigmas not often massive (15) 

14(13). Sap milky or not; stigma free from or only loosely coherent to anther- 
and/or corolla-tissue 109. Apocynaceae, p. 1331 

24 



14. Sap always milky; stigma massive and united to anther-tissue and often to 

some corolla-tissue to form a "crown" or gynostegium" 

110. Asclepiadaceae, p. 1339 

15(13). Leaves pinnately twice-compound 74. Leguminosae, p. 1039 

15. Leaves simple to pinnately once-compound or palmately compound (16) 

16(15). Anthers more than 3 times as numerous as the petals (or as the corolla 
lobes) (17) 

16. Anthers numbering from 3 times as numerous as the petals or corolla lobes to 

as few as 2 per flower (19) 

17(16). Filaments either coalescent to form a tube or at least coalescent at base 
87. Malvaceae, p. 1113 

17. Filaments not coalescent (18) 

18(17). Herbs with deeply dissected leaves and highly zygomorphic flowers 

61. Ranunculaceae, p. 913 

18. Woody plants with mostly entire leaves and actinomorphic flowers 

105. Symplocaceae, p. 1301 

19(16). Stamens (6 or) 7 to 18, usually precisely 2 or 3 times as numerous as 
the petals or corolla lobes (20) 

19. Stamens 2 to 5 (or very rarely 6), as many as the petals or corolla lobes or 

fewer than them (24) 

20(19). Carpels free, equal in number to the calyx segments or corolla lobes, 
each maturing into a follicle 69. Crassulaceae, p. 994 

20. Carpels coalescent into a compound pistil (21 ) 

21(20). Petals typically 3; flowers extremely zygomorphic; stamens 8 or rarely 
6 51. Polygalaceae, p. 1074 

21. Petals or corolla lobes 4 to 7; flowers only slightly if at all zygomorphic; sta- 

mens (6 or) 7 to 18 (22) 

22(21). Anthers often with little hornlike appendages and dehiscing by apical 
slits, clefts or pores 101. Ericaceae, p. 1267 

22. Anthers unappendaged, usually opening longitudinally (23) 

23(22). Woody plants with stellate or lepidote vestiture 

104. Styracaceae, p. 1296 

23. Plants herbaceous, vestiture absent or else not stellate nor lepidote 

78. Euphorbiaceae, p. 1082 

24(19). Ovule viviparous, i.e., germinating while still on the parent-plant; 
opposite-leaved mangrovelike small rhizomatous shrubs growing on 
salty mud flats along the Texas coast.... 115. Avicenniaceae, p. 1392 

24. Ovule not viviparous; plants not growing in salty mud or if so then not 

shrubby (25) 

25(24), Fruit an incompletely celled capsule (i.e., 1-celled with incomplete par- 
titions), dehiscing apically 58. Caryophyllaceae, p. 884 

25. Fruit otherwise, if capsular then dehiscing differently (26) 

26(25). Fruit a circumscissile capsule; herbs with leaves nearly all basal and 

flowers in dense spikes terminating the scapes 

123. Plantaginaceae , p. 1533 

26. Fruit not a circumscissile capsule or if so then habit otherwise (27) 

25 



27(26). Fruit a capsule terminated by 2 prominent curved and incurved beaks, 
1-3 dm. long 120. Martyniaceae, p. 1508 

27. Fruit not as above (28) 

28(27). Herbs with opposite leaves and the odor of wet wool (or a wet dog); 
stamens 3 (rarely 2); flowers minute, white, in terminal dichasia 
or compound cymes; calyx minute, annular, involute (often un- 
rolling after anthesis) or with minute teeth; fruit a 1 -seeded achene- 
like structure 126. Valerianaceae, p. 1562 

28. Plants not as above, usually with 2, 4 or 5 stamens and with the calyx 

usually better-developed (29) 

29(28). Herbs usually with linear leaves; fruit a capsule, more or less com- 
pletely 10-celled, at maturity splitting into 5 or 10 parts which fall 
away separately 76. Linaceae, p. 1073 

29. Herbs, shrubs or trees; fruit not as in flax (30) 

30(29). Leaves alternate and stipulate (the stipules sometimes small, deciduous) 
(31) 

30. Leaves alternate, opposite or whorled, either not having stipules or if with 

stipules then opposite (32) 

31(30). Fruit subglobose, drupaceous (with several stones), reddish to yellow- 
ish or black, usually 5-10 mm. thick 82. Aquifoliaceae, p. 1097 

31. Fruit a capsule or schizocarp 88. Sterculiaceae, p. 1125 

32(30). Leaves opposite or whorled and with stipules, the evidence of stipules 
sometimes reduced to mere stipular lines or membranes at the sides 
of the node (here may also be sought certain Rubiaceae whose 
essential epigyny has been overlooked).... 107. Loganiaceae, p. 1308 

32. Leaves opposite or alternate, without the slightest evidence of stipules (33) 

33(32). Stamens 2 or 4, fewer than the 5 corolla lobes (the number of corolla 
lobes may be obscure in highly zygomorphic corollas) (34) 

33. Stamens 5 in flowers with 5 corolla lobes or 4 in flowers with 4 corolla lobes 

(this usually easily ascertained) (40) 

34(33). Fruit not capsular, either schizocarpous and breaking into 1-seeded 
achenelike parts or else drupaceous; leaves always opposite (35) 

34. Fruit a capsule or a samara; leaves opposite or alternate (37) 

35(34). Flowers strongly zygomorphic; style usually manifestly bifurcate near 
the apex (lower branches usually shorter than the upper); fruit 
a schizocarp 117. Lahiatae, p. 1407 

35. Flowers usually only slightly if at all zygomorphic; style usually micro- 

scopically if at all bifurcate at apex; fruit schizocarpous or dru- 
paceous (36) 

36(35). Fruit a 1-seeded drupe 106. Oleaceae, p. 1301 

36. Fruit a schizocarp or a druf>e with 2 or more seeds 

116. Verbenaceae, p. 1393 

37(34). Seeds minute, attached to a free central placenta in the 1 -celled ovary; 

fruit a 2- or 4-valved capsule; small herbs 

121. Lentihulariaceae, p. 1510 

37. Seeds attached to axile or nearly axile placentas in the 2-celled ovary; fruit 

a capsule or samara (38) 

26 



38(37). Corolla lobes usually convolute in bud; capsule elastically dehiscent, the 
seeds ballistically ejected at dehiscence 122. Acanthaceae, p. 1525 

38. Corolla lobes usually imbricate or valvate in bud; capsule not elastically de- 

hiscent (or fruit a samara in some taxa), the seeds not ballistic (39) 

39(38). The 2 stamens opposite each other or at least widely separated on the 
nearly aotinomorphic corolla 106. Oleaceae, p. 1301 

39. The 2 or 4 stamens not widely separated in the usually strongly zygomorphic 

corolla 119. Scrophulariaceae, p. 1456 

40(33). Only a single seed maturing in each flower 

103. Plumbaginaceae, p. 1295 

40. At least 2 and commonly more seeds produced by each flower (41 ) 

41(40). Placenta obviously free-central, attached at base of the single cell of 

the ovary; stamens opposite the corolla lobes 

102. Primulaceae, p. 1276 

41. Placenta axile or parietal, or if basal then the ovary with more than 1 cell, 

or if placentation difficult to determine at least not obviously free- 
central; stamens alternate with the corolla lobes (but this very 
obscure in some flowers) (42) 

42(41). Ovary 3-celled; style usually 3-cleft at apex; plant never twining; sepals 
united by translucent webbing tissue....! 12. Polemoniaceae , p. 1369 

42. Ovary usually 2- or 4-celled, rarely 1-celled (43) 

43(42). Placentae parietal (but often intruded deeply into the chamber and 
meeting at the center, their parietal nature then revealed only by 
very careful dissection); seeds small and numerous; anthers after 
anthesis shriveling into a spiral or helix; leaves opposite (except in 

genus Nymphoides); cymes never scorpioid 

108. Gentianaceae, p. 1312 

43. Placentae axile or axile-basal (except parietal in some Hydrophyllaceae with 

scorpioid cymes and more than 1 stigma); seeds few to numerous; 
anthers after anthesis not shriveling into a spiral or a helix; leaves 
opposite or alternate (44) 

44(43). Fruit drupaceous or a deeply lobed schizocarp of 2 to 4 achenelike 
mericarps ...114. Boraginaceae, p. 1383 

44. Fruit a capsule or berry (45) 

45(44). Each flower with a single (sometimes shallowly 2-lobed) stigma (46) 

45. Each flower with 1 or 2 styles and at least 2 stigmas (47) 

46(45). Herbs or shrubs; leaves alternate (sometimes fascicled): flowers almost 

exclusively radially symmetrical; fruit a capsule or berry 

118. Solanaceae, p. 1449 

46. Opposite-leaved herbs with strongly zygomorphic corollas; fruit a capsule.... 

119. Scrophulariaceae, p. 1456 

47(45). Often herbaceous twining vines or rhizomatous or stoloniferous creep- 
ing herbs; flowers usually solitary from the axils; ovary usually 2- 
or 3- or 4-celled 111. Convolvulaceae, p. 1350 

47. Never twining, usually small erect taprooted herbs; flowers in cymes or heli- 

coid or scorpioid cymes, or solitary; ovary usually 1-celled (2- 
celled in Nama) 113. Hydrophyllaceae, p. 1375 

48(1). Completely submerged fresh-water aquatics with much-reduced flowers 
and very peculiar habits (cf. also Haloragaceae and Lemnaceae) 
(49) 

27 



48. Either terrestrial plants or if aquatic then not completely submerged (or only 

briefly so at some seasons), the flowers always aerial or with a less 
bizarre habit (50) 

49(48). Leaves whorled; plants usually seemingly free-floating 

60. Ceratophyllaceae, p. 912 

49. Leaves alternate, distichous; plants attached to rocks and usually in swift- 

flowing water 68. Podostemaceae, p. 993 

50(48). Stem-parasites not in contact with the soil; vegetative parts threadlike.... 
63. Lauraceae, p. 961 

50. Nonparasitic or if parasitic then appearing rooted in soil (51) 

51(50). Shrublets or subshrubs with creeping underground organs, forming 
colonies on low salty ground near and along the Texas coast; 
leaves well-developed (cf. Salicornia where they are mere scales), 
opposite, fleshy, linear; pistillate flowers aggregated into and largely 
sunken in the axes of short axillary inflorescences; staminate flowers 
in spikelike axillary inflorescences 54. Bataceae, p. 868 

51. Habitally diverse, if fleshy then having leaves reduced to scales or alternate 

leaves or the inflorescences different from Batis (52) 

52(51). Corolla absent, the flower either with no perianth or with only one series 
of perianth parts (sepals or "tepals"); (also see here Rumex with 2 
dissimilar whorls or sepals) (53) 

52. Each flower with both calyx and corolla or occasionally in families with uni- 

sexual flowers the petals absent from the pistillate ones, or in some 
taxa petals present only in the chasmogamous flower but absent 
from cleistogamous ones (95) 

53(52). Trees with flowers and fruits small and numerous in spherical heads; 
leaves palmately lobed (54) 

53. Trees, shrubs, herbs or vines with flowers not in spherical heads or if so 

then leaves not palmately lobed (55) 

54(53). Bark furrowed; leaves deeply 5- or 7-lobed to resemble a star, smooth 
and shiny (genus Liquidamhar of). ...71. Hamamelidaceae, p. 1011 

54. Bark exfoliating in thin sheets; leaves 3- or 5-lobed, usually with broad 

rounded .shallov sinuses, the undersurfaces usually pubescent 

72. Platanaceae, p. 1012 

55(53). Sepals coalescent at least near their bases either above the receptacle in 
hypogynous flowers or above the floral cup or hypanthium in peri- 
gynous flowers or above the ovary in epigynous ones (56) 

55. Sepals free from each other either completely to the receptacle in hypogynous 

flowers or above the ovary in epigynous ones, or sepals absent (67) 

56(55). Ovary completely inferior (57) 

56. Ovary superior or only partly inferior near the base (60) 

57(56). Herbs usually growing partially submerged or in mud but the flowers 
aerial (58) 

57. Plants never aquatic (59) 

58(57). Leaves (at least the immersed ones) pinnatifid to capillary-dissected; 

staments more than 1; ovary 2- to 4-celled 

96. Haloragaceae, p. 1201 

58. Leaves all entire; stamen 1; ovary 1-celled 97. Hippuridaccae, p. 1208 

28 



59(57). Erect herbs with merely opposite leaves and a pungently fetid odor (like 
that of a wet dog) 126. Valerianaceae, p. 1562 

59. Erect or often trailing herbs with whorled leaves and not strongly odoriferous 

(genus Galium of) 124. Rubiaceae, p. 1538 

60(56). Pistils several, free from each other 61. Ranunculaceae, p. 913 

60. Pistil solitary (61) 

61(60). Seeds (or ovules) campylotropous, with embryo curved around the 
periphery surrounding the perisperm or endosperm (62) 

61. Seeds not as above (64) 

62(61). Seeds solitary 53. Amaranthaceae, p. 857 

62. Seeds several to numerous (63) 

63(62). Stamens more numerous than sepals 56. Aizoaceae, p. 870 

63. Stamens as many as the sepals 58. Caryophyllaceae, p. 884 

64(61). Branches of inflorescence scorpioid (genus Penthorum of) 

70. Saxifragaceae, p. 999 

64. Branches of inflorescence (if any) not scorpioid (65) 

65(64). Leaves pinnately compound (genus Fraxinus of) 

106. Oleaceae, p. 1301 

65. Leaves simple (66) 

66(65). Ovary 1-celled; stigma solitary; stamens 2 to 5 50. Urticaceae, p. 788 

66. Ovary usually 3-celled; stigma usually more than 1; stamens usually more 

■than 5 78. Euphorbiaceae, p. 1082 

67(55). Stamen solitary; leaves opposite; low-growing subaquatics or aquatics; 
perianth absent 79. Callitrichaceae, p. 1085 

67. Stamens more numerous or if only 1 then the leaves alternate or else the 

plants woody; calyx often present (68) 

68(67). Oarpels several, distinct 61. Ranunculaceae, p. 913 

68. Carpels (when more than 1) united at least at their bases (at least at anthesis) 

(69) 

69(68). Ovary completely inferior as shown by micro- or macroscopic scales or 
sepals at top (use strong lens) and/or in some taxa by stamens at 
the very top of the ovary (70) 

69. Ovary superior or at least half-superior (75) 

70(69). Plants herbaceous (71) 

70. Plants woody; fruit a nutlike structure (72) 

71(70). Ovary of several folliclelike structures partially or almost wholly im- 
mersed in the inflorescence axis and associated floral tissue (genus 
Anemopsis of) 42. Saururaceae, p. 734 

71. Ovary not as in Anemopsis 98. Umbelli ferae, p. 1211 

72(70). Nut subtended by a cupule of more or less consolidated bracts 

48. Fagaceae, p. 783 

72. Nut not having a basal cupule of bracts (73) 

73(72). Leaves compound 46. Juglandaceae, p. 769 

73. Leaves simple (74) 

29 



74(73). Stipules present: leaves usually serrate 47. Betulaceae, p. 777 

74. Stipules absent; leaves usually entire-margined 99. Cornaceae, p. 1262 

75(69). Annual herbs; sepals 4; fruit a compressed-flattened 2-celled pod with a 
thin narrow vertical septum parallel to the direction of compression 
64. Cruciferae, p. 962 

75. Annual or perennial herbs or shrubs, trees or vines (76) 

76(75). Plants herbaceous (include in this category woody-based vines and 
herbs which may have slightly woody stems at base but which die 
back to near the base every year) (77) 

76. Plants woody, never vinelike (88) 

77(76). Embryo curved, occupying the periphery of the rounded ovule and sur- 
rounding the perisperm and/ or endosperm (78) 

77. Embryo otherwise (84) 

78(77). Each pistillate or perfect flower maturing only 1 seed (79) 

78. Each pistillate or perfect flower maturing several seeds (81 ) 

79(78). Sepals dry, scalelike, for the most part not green 

53. Amaranthaceae , p. 857 

79. Sepals herbaceous in texture (80) 

80(79). Stipules absent 52. Chenopodiaceae, p. 834 

80. Stipules present 58. Caryophyllaceae, p. 884 

81(78). Leaves alternate; flowers in terminal racemes. ...55. Phytolaccaceae, p. 870 

81. Leaves alternate or opposite; flowers not in terminal racemes (82) 

82(81). Leaves usually opposite; ovary never even slightly inferior; fruit usually 
dehiscent by terminal valves 58. Caryophyllaceae, p. 884 

82. Leaves alternate or if opposite then the fruit opening otherwise and not un- 

commonly at least slightly inferior (83) 

83(82). Each flower with 2 bracteoles (or "sepals") at base which often enclose 

the bud; ovary 1-celled or incompletely several-celled 

57. Portiilacaceae, p. 879 

83. Flowers rarely bibracteolate; ovary completely several-celled 

56. Aizoaceae, p. 870 

84(77). Fruit a capsule of several foliiclelike parts, each part dehiscing through 
the apical portion of the ventral suture 42. Saiiruraceae, p. 734 

84. Fruit not as in Saururaceae (85) 

85(84). Flowers unisexual; fruits capsular, 3-celled....78. Eiiphorbiaceae, p. 1082 

85. Flowers usually bisexual; fruits achenelike, indehiscent (86) 

86(85). Leaves palmately lobed or palmately or pinnately compound 

73. Rosaccae, p. 1015 

86. Leaves not palmately lobed (87) 

87(86). Stipules usually present, usually deciduous, never sheathing nor scarious; 
placenta apical; ovule anatropous; achene usually not shiny, often 
neither lenticular nor trigonous 50. Urticaceae, p. 788 

87. Stipules (when present) usually sheathing; placenta basal; ovule orthotropous; 

achene usually smooth and shiny, either lenticular or trigonous 

51. Polygonaceae, p. 795 

30 



88(76). Embryo curved, occupying the periphery of the rounded ovule and 
surrounding the perisperm and/ or endosperm (go back to couplet 
79). 

88. Embryo not as above (89) 

89(88). Leaves opposite (90) 

89. Leaves alternate (91) 

90(89). Fruit a drupe or a simple samara 106. Oleaceae, p. 1301 

90. Fruit a double samara, with the seed-bearing bases connate and the 2 blades 

diverging as in maple fruit 84. Aceraceae, p. 1104 

91(89). Seeds numerous, each surrounded by a basal coma of hairs 

43. Salicaceae, p. 737 

91. Seeds often 1 or few, with coma absent (92) 

92(91). Androecium of 4 series, each series of 3 stamens whose anthers open 
by 2 or 4 uplifting valves, often an additional 3 staminodia pres- 
ent 63. Lauraceae, p. 961 

92. Androecium otherwise, usually the stamens fewer than 12; anther dehiscence 

usually by longitudinal slits (93) 

93(92). Flowers perfect or unisexual with both sexes on the same plant, solitary 
or in few-flowered fascicles; calyx 4- or 5-merous; fruit a samara, 
a roundish drupe or a nutlike structure 49. Ulmaceae, p. 788 

93. Flowers unisexual, usually with male and female flowers on separate plants 

or sometimes on the same plant, in small spikes or aments; calyx 
absent at least in staminate flowers; fruit either a small wax-coated 
sphere or an elongate drupe (94) 

94(93). Fruit a small wax-coated sphere; leaves subpersistent, usually toothed or 
lobulate above the middle 44. Myricaceae, p. 767 

94. Fruit an elongate leathery-skinned drupe; leaves deciduous, usually entire- 

margined 45. Leitneriaceae, p. 769 

95(52). Ovary inferior or mostly so (96) 

95. Ovary superior or mostly so (here also see Nelumbo of the Nyphaeaceae 

whose separate ovaries are mostly immersed in the receptacle and 
Euonymus in the Celastraceae in which the massive disk may 
appear to adhere lightly to the side of the ovary) (102) 

96(95). Fruit consisting of 2 achenelike mericarps which at maturity separate 
from each other and from the receptacle. ...98. Umbelliferae, p. 1211 

96. Fruit otherwise (97) 

97(96). Embryo curved, forming the periphery of the roundish or disklike ovule, 
surrounding the perisperm and/ or endosperm (go back to couplet 
83). 

97. Embryo and ovule otherwise (98) 

98(97). Fruit a pome 73. Rosaceae, p. 1015 

98. Fruit not a pome or if resembling one then seeds numerous (99) 

99(98). Fruit a drupe 99. Cornaceae, p. 1262 

99. Fruit a berry, capsule or follicetum (100) 

31 



100(99). Usually a long hypanthium present and prolonged above and com- 
pletely obscuring the top of the ovary; stamens (often 8) usually 

precisely twice as numerous as the petals; fruit a capsule 

95. Onagraceae, p. 1175 

100. Top of ovary plainly visible at or slightly above the point of attachment 

of the stamens and perianth; fruit a capsule, berry or follicetum 
(101) 

101(100). Plants partially submerged weak-stemmed aquatics (genus Myrio- 
phyllum of) 96. Haloragaceae, p. 1201 

101. Plants not partially submerged 70. Saxifragaceae p. 999 

102(95). Filaments monadelphous or diadelphous, or confluent with a gynophore 
(anthers free or united) (103) 

102. Filaments distinct from each other or joined into more than 2 groups (108) 

103(102). Pistil solitary and simple, often folliclelike at maturity; stigma solitary 
74. Legiiminosae, p. 1039 

103. Pistil solitary but compound, rarely folliclelike; stigmas mostly more than 1 

(104) 

104(103). Flowers strongly bilaterally symmetrical; carpels usually 2; stamens 
monadelphous or diadelphous 77. Polygalaceae, p. 1074 

104. Flowers nearly radially symmetrical; carpels more than 2; stamens monadel- 

phous (105) 

105(104). Filament tube elongate and forming a more or less loose sheath not 
only around the ovary but also around the elongate style(s); 
stamens numerous; flowers perfect 87. Malvaceae, p. 1113 

105. Filament tube not so elongate (or if so then stamens only 10); stamens 

numerous or fewer; flowers perfect or unisexual (106) 

106(105). Carpels 3 as shown by number of stigmas or placentas 

78. Euphorbiaceae, p. 1082 

106. Carpels 5 (107) 

107(106). Fruit separating at maturity into 5 or 10 uni- or biovulate mericarps 
which fall separately 76. Linaceae, p. 1073 

107. Fruit not a schizocarp or if so then the cells several-seeded 

88. Sterculiaceae, p. 1 125 

108(102). Aquatic perennial herbs with thick horizontal rhizomes, rooted in mud 
at bottom of water; leaves (at least those borne at or near the sur- 
face of the water) usually peltate or very deeply rounded- 
cordate 59. Nymphaeaceae, p. 900 

108. Habit not as in the water-lily family (109) 

109(108). Pistils several (each simple) and quite separate (even at base) at 
all stages of development (110) 

109. Pistil 1. either simple or compound (in some taxa the carpels united only 

near their bases as for example the Magnoliaceae, Saxifragaceae 
and Hamamelidaceae) (112) 

110(109). Flowers with a floral cup (or "hypanthium") at the rim of which 
are attached the sepals, petals and stamens; stipules usually present; 
endosperm absent 73. Rosaceae, p. 1015 

110. Calyx, corolla and androecium hypogynous or nearly so; stipules present or 

often absent; endosperm usually present (111) 

32 



111(110). Leaves usually fleshy and succulent, simple, unlobed or usually so, 
with entire or toothed margins 69. Crassulaceae, p. 994 

111. Leaves not succulent, usually deeply lobed or compound 

61. Ranunculaceae, p. 913 

i 12(109). Carpels numerous, crowded together to cover the prolonged floral 
axis, cohering to each other and in fruit forming a fleshy or 
rather woody conelike fruit, each folliclelike carpel opening longi- 
tudinally by a dorsal slit and each carpel uni- or biovulate; trees 
or shrubs 62. Magnoliaceae, p. 958 

112. Gynoecium and fruit not as in the Magnoliaceae (113) 

113(112). Flowers bilaterally symmetrical; petals 3, bilobed; stamens 5, each 
filament with a scale and all 5 scales connivent over the stigma; 
capsules explosively dehiscent 85. Balsaminaceae, p. 1105 

113. Character combination not as above ( 1 14) 

114(113). Flowers bilaterally symmetrical; lowermost petal spurred or gibbous; 

fruit a capsule with 3 valves and 3 parietal placentae 

92. Violaceae, p. 1151 

114. Character combination not as above (115) 

115(114). Embryo curved around the periphery of the roundish or disklike 
seeds, surrounding the perisperm and/or endosperm (go back to 
couplet 78). 

115. Ovules and seeds not as in centrospermous plants (116) 

116(115). Fertile stamens precisely as many as sepals and alternate with them 
and/ or as many as petals and opposite them (117) 

116. Fertile stamens either more numerous than petals or sepals or if as few as 

petals or sepals then opposite the sepals and alternate with the 
petals (119) 

117(116). Vines; fruit a several-seeded berry 86. Vitaceae, p. 1108 

117. Mostly trees, shrubs or herbs; fruit mostly drupes or capsules or (if vines) 

then fruit a drupe (118) 

118(117). Opposite-leaved herbs; capsule circumscissile (genus Anagallis of) 

102. Primulaceae , p. 1276 

118. Alternate -leaved plants; capsule not circumscissile....88. Sterculiaceae, p. 1125 

119(116). Fruit a specialized capsule completely divided into 2 cells by a thin 
partition, each cell then with 2 placentae situated at the juncture 
of the partition and the walls, at dehiscence the 2 valves separating 

from the persistent partition (starting at base) and falling free 

64. Cruciferae, p. 962 

119. Fruit not a silique or silicle ( 120) 

120(119). Leaves tubiform, basal, trumpet-shaped, dilated upward, to 7 dm. long, 
partially filled with fluid, with a ridge on the adaxial side and 
terminated by an expanded hood to 8 cm. long; stamens numerous 
66. Sarraceniaceae, p. 990 

120. Character combination not as above (121) 

121(120). Rosettelike low nearly acaulous herbs; leaf blades usually rotund, the 
margins with gland-tipped hairs that exude drops of clear glittering 

glutinous fluid; insectivorous by means of folding leaf blades 

67. Droseraceae, p. 990 

121. Character combination not as above (122) 

33 



122(121). Tree with opposite palmately lobed leaves on long slender reddish 

petioles; fruit of geminate samaras (Acer rubrum of) 

84. Aceraceae, p. 1104 

122. Character combination not as above (123) 

123(122). Shrub or tree with alternate simple stipulate leaves; flowers usually 
perfect, small, borne in small axillary pedunculate clusters or 
heads, with 3 each of sepals, petals, stamens and staminodes and 
2 long styles; capsule bivalvate, opening loculicidally from the top; 
seed 1 in each cell 71. Hamamelidaceae, p. 1011 

123. Character combination not as above (124) 

114(123). Ovary with a slender axis 1-5 cm. long, at the base of which are 5 
small cells, each with 2 ovules; at maturity when dry the cells 
suddenly separating from the axis and coiling up on their styles 

which are also adnate to the full length of the axis 

75. Geraniaceae, p. 1071 

124. Character combination not as above (125) 

125(124). Pistil simple, folliclelike with a single style and stigma and a single 
ventral placenta 74. Leguminosae, p. 1039 

125. Pistil not simple as shown by 2 or more stigmas, 2 or more cells, or 2 or 

more placentae (126) 

126(125). Flowers unisexual; carpels 3; fruit usually a capsule and usually with 
a well-developed central axis (columella) which persists after 
dehiscence; ovules 1 or 2 in each of the 1, 2 or usually 3 cells, 

attached to an apical-axial (columellar) placenta 

78. Euphorbiaceae, p. 1082 

126. Flowers usually bisexual; carpels 2 to 10, if 3 then character combination 

not as above (127) 

127(126). Herbs with alternate palmately compound leaves (rarely reduced to 1 
leaflet); flowers hypogynous, often somewhat bilaterally symmetri- 
cal; stamens 6 to 27 or more, as long as or usually longer than the 
petals; ovary borne on a slender gynophore (rarely nearly sessile), 
1 -celled (2-celled in Wislizenia) , usually capsular with 2 valves and 
many seeds 65. Capparidaceae, p. 987 

127. Character combination not as above (128) 

128(127). Petals and stamens either definitely perigynous, i.e., inserted in a 
floral cup or "calyx tube" or very slightly epigynous (the cup at- 
tached to the very basal part of the ovary) (129) 

128. Petals and stamens hypogynous (rarely very slightly or obscurely perigynous 

as in some Celastraceae) (132) 

129(128). Leaves opposite; hypanthium urceolate; petals 4, fugacious, rose-color 
to purple (rarely white or yellow); stamens 8, basally appendicu- 

late; anthers dehiscing by apical pores 

94. Melastomataceae, p. 1169 

129. Character combination not as above (130) 

130(129). Herbs; leaves mostly basal; ovary very shortly at base adnate to a 
floral cup; stigmas 4; capsule 1 -celled, 4-valved; stamens 5, plus 
5 staminodes (genus Parnassia of) 70. Saxifragaceae , p. 999 

130. Ovary superior; style 1, 2, 3 or 5, never 4; stamens 4 to numerous (131) 

34 



131(130). Flowers usually uniformly 5-merous; stamens 10 to 40, inserted near 
the rim of the floral cup not very far from where the petals are 
inserted; stipules present 73. Rosaceae, p. 1015 

131. Flowers 4- to 7-merous; stamens 4 to numerous, usually inserted well down 

into the calyx tube or floral cup, whereas the petals are inserted 
near the rim between the short calyx teeth; stipules minute or 
usually absent 93. Lythraceae, p. 1154 

132(128). Shrubs or trees with numerous twigs and very numerous alternate 
scalelike or nearly terete leaves only about 1 mm. long, the entire 
plant often appearing grayish; flowers pink or white, very small, 
inconspicuous 91. Tamaricaceae, p. 1148 

132. Character combination not as above (133) 

133(132). Leaves opposite, simple and gland-dotted (as seen with transmitted 
light); styles often separate or nearly so or only lightly cohering 
until after anthesis; mostly herbs or weak-stemmed shrubs; sepals, 
petals and stamens free and hypogynous or stamens in 5 phalanges 
opposite the petals; placentae parietal or usually axile; ovules 
usually numerous; fruit a capsule; stamens 6 to numerous, when 

numerous tending to be in as many groups as there are petals 

89. Hypericaceae, p. 1127 

133. Character combination not as above but if most of the characters are similar 

then the leaves mostly alternate or the styles permanently united 
(134) 

134(133). Shrubs or small trees of eastern Texas; flowers usually white, in 
elongate racemes usually 5-20 cm. long and only 1 cm. thick (135) 

134. Habit various but if flowers in elongate racemes then plants herbaceous 

(136) 

135(134). Fruit dehiscent... 100. Clethraceae, p. 1267 

135. Fruit indehi&cent 81. Cyrillaceae, p. 1095 

136(134). Fruit indehiscent and usually fleshy, usually 1-seeded (137) 

136. Fruit dehiscent, usually dry at maturity (138) 

137(136). Leaves simple, usually stipulate; stamens never more numerous than 
petals; drupes usually nearly circular in transection, not resinous, 
usually glabrous 82. Aquifoliaceae, p. 1097 

137. Leaves usually compound, usually exstipulate; stamens as many as or rarely 

twice as many as the petals; drupes usually somewhat flattened, 
resinous, often pubescent 80. Anacardiaceae, p. 1091 

138(136). Flowers with thick-lobed disk that fills the bottom gf the calyx and 
sometimes hides much of the ovary; plants woody, with 4 sided 
green-barked branchlets; seeds with bright-red arils (genus Euony- 
mus of) 83. Celastraceae, p. 1103 

138. Disk (if present) not so thick; plants various in habit but usually mostly 

herbaceous in texture; seeds not with bright-red arils 

90. Elatinaceae, p. 1 142 

35 




Fig. 4: a and b, Psilotum nudum: a, habit, x ^,4; b, sporangium, x 4. c, Marsilea 
Fournieri: c, habit, x %, with leaf, x 2. d, Marsilea mexicana: d, habit, x %, with leaf, 
X 2, and sporocarps, about x 2V.. e, Ophioglossum Engelmannii: e, habit, x %, with 
section of sterile leaf blade enlarged. 



Division I. Pteridophyta 



Ferns and Fern Allies 



Terrestrial, epiphytic, saxicolous or occasionally aquatic plants with a life cycle 
of two distinct phases — Sporophyte and Gametophyte. The sporophyte is usually 
differentiated into root, stem and leaf provided with vascular tissue (phloem and 
xylem), and produces spores asexually that are either alike (plants homosporous) 
or of two very unlike kinds called microspores and megaspores (plants heteros- 
porous). The spores germinate to produce the gametophyte or minute incons- 
picuous sexual stage (prothallium). In the homosporous series the prothallia are 
similar but may be either monoecious or dioecious; in the heterosporous series 
they are dissimilar and dioecious — the ones developing from microspores bearing 
only male reproductive organs (antheridia), and those from megaspores only 
female organs (archegonia). Fertilization consists of the impregnation of an egg 
cell (archegonia) by the coiled motile male cell (spermatozoid); the resulting 
growth is the sporophyte or usually conspicuous asexual stage commonly known 
as a fern or fern ally. 

The Pteridophyta include more than 9,000 species in about 215 genera. Although 
world-wide in distribution, they attain their greatest number and luxuriant develop- 
ment in the tropics and subtropics. Approximately 345 species in about 60 genera 
are found in North America north of Mexico. 

Fam. 1. Psilotaceae Eichler Whisk Fern Family 

Terrestrial or more or less epiphytic perennial plants with short creeping 
coralloid rhizomes; aerial stems and branches wiry, dichotomously branched, with 
minute remote alternate scalelike leaves; sporangia somewhat depressed-globose 
and 3-celled, opening at the apex into 2 or 3 valves, sessile in the axils of the 
usually 2-lobed minute sporophylls on the upper part of the numerous branches; 
spores all alike, numerous. 

A small family of two genera, Tmesipteris of Oceania and Australasia, with 
several species, and Psilotum. 

1. Psilotum Sw. 

Characters of the family. About 3 species that are widely distributed in tropical 
or warm temperate regions throughout the world. 

1. Psilotum nudum (L.) Beauv. Fig. 4. 

Plants dichotomously branched 3 to 5 times, usually about 25 cm. tall, rarely 
to 5 dm. tall; common stalk simple, 3-angled, to 4 mm. thick; branches lightly 
winged along the 3 angles; scalelike leaves about 1 mm. long; sporophylls rudi- 
mentary. 

In swamps and low wet woods about base of trees and stumps, more or less 
partly saprophytic, in s.e. Tex., summer; from Fla., n. to S.C, w. to Tex., 
through Mex. and C. A. to s. S. A. and in W.I.; also widely distributed in the 
Old World trop. 

37 




Fig. 5: 1, Lycopodium carolinianum: 1, plant, x %, with enlarged peduncle leaf 
and sporophyll. 2, Lycopodium alopecuroides: 2, plant, x %, with enlarged peduncle 
leaf and sporophyll. 3, Lycopodium adpressum: 3, plant, x %, and enlarged sporangium. 

4, Isoetcs lithopliylla: 4, plant, x 1, and enlarged sporangium. 5, Isoetes melanopoda: 

5, plant, X 1, and enlarged sporangium. (From Correll in Lundell's Flora of Texas, 
Vol. 1, PI. 3.) 



Fam. 2. Lycopodiaceae Reichb. Clubmoss Family 

Low terrestrial erect or trailing perennial plants; stems mostly prostrate or 
arching and giving rise to aerial peduncles or branches, alternately branched 
or repeatedly dichotomous, densely or sparsely covered with small leaves; leaves 
numerous, mostly small and thin, 1 -nerved, usually uniform and imbricate, several- 
to many-ranked, rigidly ascending to spreading-reflexed; sporophylls similar to 
the vegetative leaves or more or less modified, crowded into a cone at the apex 
of the aerial stems; sporangia large, in the axils of the sporophylls, uniform, 
1-celled; spores all alike (plants homosporous), small, globose, light yellow; 
prothallia fleshy, tuberous, monoecious. 

This family is composed of two genera, the monotypic genus Phylloglossum, of 
Australia and New Zealand, and Lycopodium. 

1. Lycopodium L. Clubmoss 

Characters same as those of the family. About 450 species that are found 
mainly in temperate and mountanous tropical regions. 

1. Stems arching and rooting, not truly prostrate; stem leaves spreading radially.. 
L L. alopecuroides var. alopecuroides. 

1. Stems prostrate (2) 

2(1). Foliage leaves unlike sporophylls; stem leaves spreading, arranged so as 
to appear 2-ranked 3. L. carolinianum. 

2. Foliage leaves and sporophylls similar (3) 

3(2). Sporophylls incurved, appressed; cone slender, only slightly thicker than 
the supporting peduncle 2. L. adpressum. 

3. Sporophylls more or less spreading; cone stout, 2 to 3 times the diameter of 

the supporting peduncle 1. L. alopecuroides var. pinnatum. 

1. Lycopodium alopecuroides L. var. alopecuroides. Foxtail clubmoss. Fig. 5. 
Peduncles to 35 cm. tall; cone 2-10 cm. long; leaves linear-lanceolate, bristle- 
toothed below, 6-8 mm. long; sporophylls similar to leaves in shape and size. 

In wet places in savannahs and boggy areas in low open pinelands in s.e. Tex., 
July-Nov.; from Fla., in the Coastal Plain, n. to N.Y. and w. to Tex.; also S.A. 

The outstanding characteristic by which var. alopecuroides is most easily recog- 
nized in the field is the arching stem that usually roots at the tip when it touches 
the ground, and the several more or less erect peduncles. 

Var. pinnatum (Chapm.) Lloyd & Underw. Creeping foxtail clubmoss. The 
prostrate habit of this variety is the only characteristic separating it from var. 
alopecuroides. L. prostratum Harper. Apparently isolated in Travis Co., Tex.; 
also from cen. La., e. to Fla. and n. along the coast to N.C. 

2. Lycopodium adpressum (Chapm.) Lloyd & Underw. Southern clubmoss. Fig. 5. 
Peduncles to 3 dm. tall and about 3 mm. in diameter; cone slender, 2-7 cm. 

long; leaves linear-lanceolate to lanceolate, entire or slightly toothed below, 6-7 
mm. long; sporophylls similar to the leaves. L. alopecuroides var. adpressum 
Chapm. 

In depressions in savannahs and flat open pinelands, bogs and sphagnous 
habitats in e. and s.e. Tex., lune-Oct.; mostly on Coastal Plain from Fla., n. to 
N.Y. and w. to Tex. 

The incurved appressed leaves on the peduncle and the slight difference in 
size between the peduncle and cone are distinctive. 

39 







:^ 



Fig. 6: 1, Equisetum laevigatum: 1, basal and upper sections of fertile stem (x 1) 
and somewhat enlarged sheath. 2, Equisetum hyemale var. affine: 2, several sections 
of fertile stem (x 1) and somewhat enlarged sheath. 3, Equisetum kansanum: 3, upper 
section of fertile stem, x 1. 4-7. Sclagim-Ua apoda: 4, fertile plant, x 1; 5, fertile spike, 
X 5; 6, sporophyll, x 10; 7, foliage leaf, x 10. (In part from Correll in Lundell's Flora 
of Texas, Vol. 1, PI. 2.). 



3. Lycopodium carolinianum L. Slender clubmoss. Fig. 5. 

Peduncles slender, rigidly erect, to 25 cm. tall and 1.5 mm. in diameter; cones 
1-5 cm. long and about twice the diameter of the peduncle; leaves of the peduncle 
subulate, in whorls or scattered, about 5 mm. long; sporophylls broadly ovate to 
deltoid, acuminate, about as long as the peduncle leaves. 

Rare in depressions in savannahs, seepage areas and open flat pinelands in s.e. 
Tex., July-Sept.; from Fla., n. to N.Y., w. to Tex.; also occurring as variants in 
S.A., Asia, Afr., Austral, and N.Zeal. 

The erect slender peduncle with scattered small leaves and sporophylls different 
from the foliage leaves is distinctive. 

Fam. 3. Selaginellaceae Mett. Spikemoss Family 

Small terrestrial or saxicolous plants of spreading habit, prostrate to ascending 
or suberect, usually profusely branched, with slender stems; stems leafy, usually 
producing wiry elongate rhizophores at some or all the nodes; leaves all alike or 
of two kinds, elliptic to lanceolate, several-ranked or in two planes, numerous, 
minute, 1 -nerved, obscurely ligulate, approximate to widely imbricate; sporophylls 
somewhat modified, borne in compact sessile cones at the apex of branches; 
sporangia of two kinds (plants heterosporous), solitary in the axils of sporophylls, 
1 -celled; megasporangia containing 1 to 4 rather large megaspores; microsporangia 
containing numerous microspores. 

Only one genus in the family. 

1. Selaginella Beauv. 

Characters same as those of the family. About 700 species are recognized in 
this complex genus that is highly developed in tropical and subtropical regions of 
both hemispheres. 

1. Selaginella apoda (L.) Spring. Meadow spikemoss. Fig. 6. 

Plants prostrate-creeping or ascending (especially when in dense shade), pale- 
to dark-green, flaccid, frequently forming large mats, annual; stems very slender, 
filamentous, somewhat angled, much-branched, to 25 cm. long or more; leaves 
dimorphic, membranous, spreading in 2 planes; lateral leaves 2-ranked, alternate, 
distant, spreading, obliquely ovate to ovate-elliptic, obtuse to acute, with the 
margins serrulate, 1.5-2 mm. long, about 1 mm. wide; dorsal leaves smaller than 
the lateral leaves, ovate to ovate-lanceolate, shortly cuspidate, with the margins 
serrulate, about 1.2 mm. long, less than 1 mm. wide; spikes obscurely quad- 
rangular, 5-20 mm. long, 2-4 mm. in diameter; sporophylls about as long as 
the lateral stem leaves, ovate to ovate-lanceolate, acute to subacuminate, keeled 
in the upper half; megasporangia yellowish, 0.5-0.9 mm. in diameter, most abun- 
dant toward base of spike; microsporangia reddish, very small, less than 0.1 mm. 
in diameter. 5. ludoviciana A. Br. 

In moist or wet places, usually in partial shade, in e. Okla. and e. and s.e. 
Tex., w. into the Edwards Plateau and Rio Grande Plains, May-Dec; from Me. w. 
to B.C., s. to Fla. and Tex. 

Fam. 4. Isoetaceae Reichb. Quillwort Family 

Small herbaceous perennial aquatic or terrestrial sedgelike plants with short 
unbranched 2- to 5-lobed subterranean cormlike rhizomes that produce numerous 
branched roots and a tuft of compact erect or recurved rushlike leaves (sporo- 
phylls); leaves bearing a small membranous ligule on the inner surface just above 
the sporangium; sporangia of two kinds, sunken in the axils of the leaf bases, more 

41 




Fig. 7: a and b, Pilularia americana: a, habit, showing the filiform bladeless leaves, 
the young ones coiled, and the stalked sporocarps, x 6; b, sporocarp (cross section), 
showing the sporangia, x 12. c-e, Isoetes Bolanderi: c, megasporangium on adaxial 
side of leaf base, the upper part partially covered by the velum, the ligule free, x 3; 
d, microsporangium on adaxial side of leaf base, the upper portion partially covered 
by the velum, the ligule free, x 3; e, habit, x %. (From Mason, Fig. 5). 



or less covered by a velum; the microspores germinate into prothallia that bear 
only a solitary antheridium; the megaspores germinate into prothallia that bear 
only archegonia. 

This family is represented by two genera, Isoetes and Stylites. 

1. Isoetes L. Quillwort 

Characters same as those of the family. About 75 species that are wide- 
spread in temperate and tropical regions of both hemispheres. 

A compound microscope is usually necessary in order to determine species. 

It has been noted that ducks seek out and eat the cormlike rhizomes and 
sporangia masses at the base of the plant, and muskrats are known to eat the 
crisp rhizomes. Wildfowl and grazing animals are also known to eat the grasslike 
sporophylls. 

1. Velum complete; megaspores dark-brown when wet, small-tuberculate; leaves 
12 cm. long or less; plants light-brown at base 1. /. lithophylla. 

1. Velum narrow, usually covering not more than one third of sporangium (2) 

2(1). Megaspores with tubercles frequently confluent into wrinkles; distribution 
Arizona 2. /. Bolanderi. 

2. Megaspores with chiefly simple tubercles; distribution Oklahoma and Texas (3) 

3(2). Megaspores less than 480 microns in diameter; sporangia 5-30 mm. long, 
brown-spotted, with narrow to broad velum 3. /. melanopoda. 

3. Megaspores more than 480 microns in diameter; sporangia 6-7 mm. long, 

usually brown-lineolate, the velum wanting or very narrow. 

4. /. Butleri. 

1. Isoetes lithophylla Pfeifi'er. Fig. 5. 

Corm 2-lobed, small; leaves 6 to 14, 10-12 cm. long, slender but not filiform, 
flexuous; stomata numerous; peripheral strands variable, none or 3, weak; ligule 
very small, cordate-triangular; sporangium 2.5-4 mm. long, orbicular to oblong, 
completely covered by velum; megaspores 290-360 microns in diameter, with 
prominent high rather narrow commissural ridges; surface of megaspores gray 
when dry, brown when wet, smooth or faintly marked with low short or somewhat 
extended usually distant ridges; microspores dark brown, chiefly 30-33 microns 
long, high-tuberculate or spiny. 

In shallow depressions and temporary pools on rock outcrops and mts. of 
granite, found only in Burnet and Llano cos. on the Edwards Plateau in Tex. 
where it is apparently endemic, Apr.-June. 

2. Isoetes Bolanderi Engelm. Fig. 7. 

Corm usually conspicuously 2-lobed; leaves 6 to 25, conspicuously quill-like, 
6-15 cm. long, rarely more; stomata very few; ligule small, cordate; sporangium 
3-4 mm. long, orbicular to oblong, at most one-third covered by velum; mega- 
spores white to bluish, 300-480 microns in diameter, the tubercles sometimes 
aggregated into wrinkles; microspores 23-30 microns long, more or less spinulose. 

Submersed in bottom of lakes and ponds in shallow to deep water, rare in 
Ariz. (Apache and Coconino cos.); B.C. s. to Mex. 

Plants small in all characters have been recognized as var. pygmaea (Engelm.) 
Clute. Calif., Nev. and Ariz. 

3. Isoetes melanopoda Gay &. Dur. Fig. 5. 

Corm 2-lobed; leaves 15 to 60, slender, erect, firm, bright green, 15-40 cm. 
long, usually black and shining at base, with usually pale membranaceous border, 
little (2-3 cm.) extended above sporangium level; stomata present; peripheral 
strands 4 or 6 cardinal, plus as many as 14 accessory groups; ligule subulate- 
triangular; sporangia oblong, 5-30 mm. long, marked by numerous brown spots; 

43 




Fig. 8: Equisctum arvensc: A, habit; a, early sporophyll-bearing plant; b, later, 
vegetative stem; B, enlarged branch; C, sporangiophores; D, sheath; E. spores, showing 
elators. (From Reed, Selected Weeds of the United States, Fig. 2). 



velum variable, from very narrow to covering nearly one half of sporangium; 
megaspores 280-440 microns in diameter, marked with low tubercles, frequently 
confluent into short low wrinkles; microspores frequently ashy-gray, 20-30 microns 
long, finely spinulose. Incl. var. pallida Engelm. 

In shallow ponds, bogs, old buffalo wallows, wet thickets and woods (especially 
pinelands), in seasonal streams and temporary sedge-grass puddles in meadows 
and prairies, and in temporary pools on granite outcrops, rare in Okla. (Atoka 
Co.), widely distributed but uncommon in e. Tex., w. to Mason Co. on Edwards 
Plateau, Mar.-Oct.; from N.J., w. to Minn., 111. and S.D., s. to Ga., La., Okla. and 
Tex. 

4. Isoetes Butleri Engelm. 

Superficially resembling a pale-based form of /. melanopoda, smaller, dioecious; 
leaves 8 to 30, almost bristleform, with triangular cross section, 8-22 cm. long, 
0.5-1.2 mm. broad, pale at base, with broad dissepiments, slender air-canals and 
4 bast-bundles, the pale sheaths granular on the back; sporangia 6-7 mm. long, 
commonly covered with brown lines, with velum wanting or very narrow; ligule 
subulate, with the base cordate; megaspores (360-) 480-650 microns in diameter, 
covered with many low and distinct (sometimes confluent) wartlike tubercles; 
microspores 27-37 microns long, covered with papillae. 

Rocky slopes, springy places, seepage areas, flats and depressions in Okla. 
(Atoka Co.); Tenn., Mo. and e. Kan., s. to Ark. and Okla. 

Fam. 5. Equisetaceae Rich. Horsetail or Scouring-rush 
Family 

Large or small terrestrial rushlike plants with wide-creeping branching perennial 
rhizomes; roots felted, annual; aerial stems usually erect, perennial or annual, 
cylindric, fluted, stout or slender, jointed, simple or with whorls of branches 
at the solid nodes, with usually hollow internodes, often roughened by a coating 
of silex; stomata arranged in regular rows or broad bands in the grooves; stem 
leaves minute, reduced and united to form toothed sheaths at the nodes, the 
free or connivent apical teeth persistent or deciduous; sporophylls aggregated 
into a cone or strobile at the summit of the main stem or at the apex of the 
branches, modified as stalked peltate scales; sporangia 6 or 7 under each scale, 
opening down the inner side; spores all alike, numerous, green; prothallia in 
damp places above ground, green, monoecious or dioecious, variously lobed. 

The family is represented only by the following genus. 

Our species are of lesser importance to animal and bird life than those found 
farther north. The plants are incidentally browsed and eaten by cattle, deer and 
muskrats, and some waterfowl are known to eat the rootstocks and stems. 

1. Equisetum L. 

Characters same as those of the family. A complex genus consisting of about 
23 species that are widespread in both hemispheres. 

1. Aerial stems dimorphic; fertile stems light-brown, early-withering; sterile stems 
green, with regular whorls of branches 1. E. arvense. 

1. Aerial stems uniform, without regular whorls of branches (2) 

2(1). Cones rounded at the summit, without a firm sharp tip; stems annual, soft 
and easily crushed 2. E. kansanum. 

2. Cones tipped by a firm dark point; stems perennial (evergreen), firm and 

resistant or somewhat soft (3) 

45 



3(2). Sheaths dilated upward, green (when young), with a narrow black band at 
the summit below the promptly deciduous teeth, frequently with a 
second irregular band below; stems smoothish, only slightly 
scabrous 3. E. laevigatum. 

3. Sheaths cylindric, tightly pressed to the stem, ashy-gray, usually with 2 black 
bands, sometimes entirely black, the teeth mostly subpersistent or 

irregularly deciduous; stems firm, scabrous 

4. E. hyemale var. affine. 

1. Equisetum arvense L. Bottle brush. Fig. 8. 

Rhizome extensively creeping and branching, dark-felted and tuberiferous; 
aerial stems dimorphic, with scattered stomata; fertile stems appearing in early 
spring, erect, usually thick and succulent, light-brown to yellowish-white, simple, 
to about 3 dm. tall, soon withering, provided with conspicuous lax scarious some- 
what dilated nodal sheaths that have 8 to 12 brown lance-acuminate teeth; cones 
cylindric to ovoid, obtuse, to 4 cm. long and 1 cm. diameter; sterile stems appear- 
ing as the feitile stems wither, erect to ascending, slender, green, 8- to 14-furrowed, 
with whorls of branches at the upper nodes, to about 7.5 dm. tall, usually smaller, 
the nodal sheaths tipped with about 12 sharp brown teeth; branches numerous in 
dense verticils, spreading to ascending, solid, mostly simple and 2.5 dm. long or 
less, about 1 mm. thick, 3- or 5-angled, provided with sheaths that have erect 
triangular-lanceolate sharp teeth. 

In sandy or clayey soil along streams and about lakes, in meadows, low ground 
and open woodlands, and on railroad embankments, in Tex. found only at Buffalo 
Spring (now known as Buffalo Lakes) in Lubbock Co., in the Plains Country, 
rather widespread and frequent in the mts. of N.M. (Colfax, Catron, Sandoval, 
Mora, San Miguel, Taos and Rio Arriba cos.) and Ariz. (Apache, Navajo, 
Coconino, Graham and Gila cos.); from Nfld. w. to Alas, and s. to N.C., Ala., 
Tex., N.M., Ariz, and Calif.; also Euras. and N.Afr. 

Forma ramulosum (Rupr.) Klinge has been found in Arizona (Gila Co.). Its 
branchlets are again branched. 

2. Equisetum kansanum J. H. Schaffn. Summer scouring-rush. Fig. 6. 

Stems 3-10 dm. tall, 2-7 mm. in diameter, usually very smooth to the touch, 
light-green; sheaths elongate, dilated upward, pale-green except for a narrow 
black band at summit, the articulate teeth soon deciduous; cone sessile or shortly 
pedunculate, 1-2.5 cm. long, 5-8 mm. in diameter. 

In moist or dry sandy or clayey soil, on bluffs, along irrigation ditches and 
lakeshores, in prairies, ditches, sloughs and among grasses and shrubs in marsh 
and swamp areas, in Tex. mostly in the Plains Country, Trans-Pecos and s.e. 
Edwards Plateau, with a lone station in Somervell Co. in the Blackland Prairies; 
from Mich, to B.C., s.w. through the Lake States to Mo., Tex., N.M. and s. 
Calif.; also n. Mex. 

Except for the absence of the hard blackish apicule on its cone, the smoother 
texture of its cone, and its annual habit, this species approaches very closely 
E. laevigatum. Its obvious relationship to that species has resulted in its being 
recently relegated to it as subsp. Funstonii (A. A. Eat.) Hartman. 

Two rather insignificant growth forms of this species occur in our area; f. 
caespitosum (A. A. Eat.) Broun, with many small rough stems clustered around 
a large central one, and f. variegatoides (A. A. Eat.) Broun, with 6 to many small 
prostrate to ascending stems arising from the apex of the rhizome or about the 
old stems of the previous year. 

3. Equisetum laevigatum A. Br. Cola de caballo, canuela, smooth scouring- 

rush. Fig. 6. 

Rhizome creeping and ascending, dark-brown to blackish, naked, with felted 
46 



I 



roots; aerial stems evergreen, simple or occasionally sparingly and irregularly 
branched, frail to somewhat stout, pale-green, mostly clustered, 3-15 dm. tall, 
to 8 mm. in diameter, longitudinally 14- to 30-grooved, with the ridges smooth 
or slightly scabrous; sheaths elongate, dilated upward, marked with a black 
girdle at the base of the mostly deciduous white-margined subulate brownish teeth 
and rarely also at the base of the sheaths, with the ridges of the sheaths 1- to 
3-keeled, the lowermost sheaths 5-12 mm. long; cones ellipsoid, sharp pointed, 
1-2 cm. long, 7-10 mm. in diameter. 

Distinguished from E. hyemale, which it closely resembles, by its smoothness, 
long green sheaths with a narrow black limb, and darker green color. Forma 
scabrellum (Engelm.) Broun has more prominent cross bands of silex on the 
ridges than in f. laevigatiim. 

In sandy soil or sandy loam along streams and lake banks, on seepage slopes, 
in alluvial thickets, marshes, meadows, prairies, sandy barrens and rocky creek 
beds of canyons, rather generally distributed in Okla., w. and cen. Tex., e. to 
Somervell and Waller cos. in the Blackland Prairies and s. to Starr Co. in 
the Rio Grande Plains, throughout N.M. and Ariz. (Navajo and Coconino, s. to 
Cochise, Santa Cruz and Pima cos.); from Anticosti Is. and Que. to B.C., s. to 
N.C., La., Tex., N.M., Ariz, and Calif.; also Mex. and Guat. 

4. Equisetum hyemale L. var. affine (Engelm.) A. A. Eat. Canuela, tall 

SCOURING-RUSH. Fig. 6. 

Rhizome slender, creeping, blackish, with a ferruginous tomentum covering 
the fibrous roots; aerial stems erect, evergreen, stout, solitary or cespitose, fluted 
with many ridges that are scabrous with bands of siliceous tubercles, to 3 m. 
tall and 2.5 cm. in diameter, simple or proliferous-branching near the apex; 
branches fertile, similar to the primary stems but conspicuously reduced in size; 
sheaths cylindric, not dilated above, variable, usually with a black band at the 
base and apex, with the central portion whitish-gray to pinkish, the ridges 
obscurely keeled, 5-12 mm. long; marginal teeth of the sheaths long and flexuous, 
reddish-brown to almost black, usually with a narrow whitish hyaline border, 
subpersistent to deciduous; cones ovoid to cylindric-ellipsoid, apiculate, 1.5-2.5 
cm. long, 5-10 mm. in diameter. E. prealtum Raf., E. robustum A. Br., E. 
hyemale var. robustum (A.Br.) A. A. Eat. 

In sandy or loamy soil in open or wooded areas along streams and on alluvial 
flats, in seepage and on wet ledges, rather generally distributed throughout Okla. 
and Tex. but most frequent in the Blackland Prairies and on the Edwards Plateau 
in the latter state, through N.M. to Ariz. (Apache, Navajo and Coconio, s. to 
Cochise, Santa Cruz and Pima cos.); represented in most of the U.S. and Can. 
as well as in Mex. and Euras. 

Two insignificant forms of this species occur in Texas; f. Drummondii (Milde) 
Broun having very tight sheaths adorned with black and white rings, and f. 
texanum (Milde) Broun with long green ampliated sheaths. 

This is our largest species in the genus Equisetum. It is one of a number of 
species in the genus that assimilate a large amount of silica. Because of the 
abundant storage of silica in the stem, they were at one time utilized in rural 
districts in this country and in the Old World to scour metal kitchen utensils, 
giving rise to the name "scouring-rush." "\.'-'J'^> 

Fam. 6. Ophioglossaceae Presl. Adder's-Tongue Family 

Succulent or herbaceous terrestrial or occasionally epiphytic plants with short 
fleshy rhizomes bearing numerous fibrous to tuberous-thickened roots; fronds 
solitary or clustered, the blade erect or bent in bud (not circinate), erect or 

47 




Fig. 9: 1, Marsilea tenuifolia: 1, plant, x %. 2, Marsilea macropoda: 2, plant, x %. 
3, Marsilea uncinata: 3, plant, x %. 4, Marsilea mucronata: 4, plant, X %. 5, Ophio- 
glossum nudicaule var. tenerum: 5, plant, x 1. 6, Ophio^lossum petiolatum: 6, plant, 
X 1. 7, Ophiof^lossum crotalopliornides: 7, plant, x 1. 8 and 9, Ophioglossum vulf^atum: 
8, plant, X %; 9, tip of leaf, slightly enlarged. (From Correll in Lundell's Flora of 
Texas. Vol. 1, PI. 8). 



pendent when epiphytic, consisting of a basal common stalk bearing at its apex a 
simple to variously compounded sessile or stalked sterile blade and (if fertile) 
one or more erect or pendent stalked spore-bearing spikes or panicles; sporangia 
in two rows, naked, opening by a transverse slit, formed from the interior tissue 
of the sporophyll; spores numerous, all alike, yellowish; prothallia subterranean, 
not green. 

This family is composed of four genera and about 70 species in tropical and 
temperate regions throughout the world. 

1. Ophioglossum L. Adder's-Tongue 

Small fleshy-succulent terrestrial or epiphytic plants of wet or moist soils, 
with short (sometimes bulbous) subterranean rhizomes bearing fibrous roots; 
fronds one or more from the same rhizome, erect in vernation, glabrous; common 
stalks slender, terete; sterile blades simple or palmatifid (in the Floridian O. 
palmatum L.), sessile or short-stalked, with the veins profusely reticulate; fertile 
spikes slender, erect, long-stalked; sporangia large, coalescent in two ranks, sub- 
globose; spores numerous, yellow; buds of the following season borne at the apex 
of the rhizomes, exposed, free. 

About 40 species of wide distribution in both hemispheres. 

1. Rootstocks globose-bulbous; leaf blades (when spread out) with a cordate to 
very broadly cuneate base 1. O. crotalophoroides. 

1. Rootstocks cylindric to subglobose, not globose-bulbous; leaf blades with a 

rounded to cuneate base (2) 

2(1). Blade distinctly and prominently apiculate; principal veins characteristically 
forming large primary areoles in which are included numerous 
veinlets forming secondary areoles 4. O. Engelmannii. 

2. Blade rounded to acute at apex, rarely minutely apiculate; principal veins 

forming areoles not enclosing smaller secondary areoles but some- 
times with included free veinlets (3) 

3(2). Blade inserted near base of plant; rootstocks subglobose 

2. O. nudicaule var. tenerum. 

3. Blade inserted towards middle of plant; rootstocks cylindric (4) 

4(3). Blade small, usually less than 5 cm. long, typically ovate-lanceolate and 
acute, with 4 to 8 parallel veins passing down through base of 
blade 3. O. petiolatum. 

4. Blade larger, usually more than 5 cm. long, broadly elliptic to oblong-elliptic 

or very rarely ovate, rounded at apex, typically with 8 to 20 parallel 
veins passing down through base of blade 5. O. vulgatum. 

1. Ophioglossum crotalophoroides Walt. Bulbous adder's-tongue. Fig. 9. 

Plants usually short, fleshy, to about 15 cm. tall; rootstock tuberous, globose, 
hard when dry, averaging about 8 mm. in diameter, producing several fronds 
during a single growing season; common stalk mostly less than 3 cm. long; sterile 
blade orbicular-ovate to ovate, when spread out cordate to sometimes very broadly 
cuneate at base, rounded to subacute at apex, abruptly contracted to a short 
petiolulate base, often conduplicate and clasping the stalk of the spike, thick- 
herbaceous, to 3.5 cm. long and 2.5 cm. wide; venation mostly obscured by the 
thick texture of the blade, forming very unequal areoles with very few included 
free veinlets; fruiting spike usually on a short stalk that is to 7 cm. long, thick 
and abbreviated, sharp at the apex, 3-4 mm. in diameter; sporangia 3 to 12, 
partly imbedded in the rachis. O. pusillum Nutt. 

In damp or wet pastures, moist sandy soil of open pine forests, and on grassy 
slopes, only in Tex. in our region, rare in s.-cen. and s.e. Tex. (Bastrop, Hardin 

49 



and Harris cos.), found once on top of Enchanted Rock (Llano Co.), reported 
by Reverchon from Newton Co. in the Timber Belt; from cen. peninsular Fla. to 
S.C. and w. to Tex.; also from Mex. to S.A. 

2. Ophioglossum nudicaule L. f. var. tenerum (Prantl) Clausen. Fragile 

adder's tongue. Fig. 9. 

Plants mostly small and inconspicuous, to 12 cm. tall, usually much smaller; 
rootstock subglobose, less than 5 mm. in diameter; common stalk very short, 
mostly less than 1 cm. long; sterile blade near base of plant, sessile to somewhat 
petioled, ovate to elliptic or occasionally somewhat oblanceolate, subobtuse to 
narrowly acute at apex, to 1.5 cm. long and 8 mm. wide; veins forming rather 
long irregular areoles without included veinlets; fruiting spike on a very slender 
elongate weak stalk, much-exceeding the sterile blade, with a sharp tip, to 2 mm. 
in diameter; sporangia as many as 12 on each side of the rachis. 

On grassy slopes and in wet meadows, damp depressions in pinelands, moist 
open woods, and on the edge of bogs, rare in Hardin Co. in s.e. Tex.; from Fla. 
and Ga., w. to Tex.; also Mex. to Arg., the W.I., Sumatra and the Phil. 

3. Ophioglossum petiolatum Hook. Fig. 9. 

Plants 6-21 cm. tall; rootstock short, cylindric, slender, erect, bearing several 
long fleshy roots and one or usually several fronds during a single growing season, 
commonly reproducing vegetatively by means of modified long slender roots 
whose buds give rise to new plants; common stalk 2-9 cm. long; sterile blade 
sessile or cuneate into a short petiole, inserted toward middle of plant, ovate to 
ovate-lanceolate or elliptic-ovate, acute at the apex, thin in texture, 1.5-6 cm. 
long, to about 1.7 cm. wide; veins few, forming large areoles; fertile stalk to 
9 cm. long; fruiting spike 1-4 cm. long; sporangia 0.5-1 mm. in diameter. 

In moist meadows, damp grassy places, depressions in old inland or coastal 
dunes, occasionally in moist woodlands and thickets, in Tex. only in Winkler Co. 
in dunes about 10 mi. n.e. of Kermit, in the Plains Country; in Fla., S.C. and 
Tex., Mex., the W.I. and n. S.A.; also in tropical Afr., Asia and Oceania, 

4. Ophioglossum Engelmannii Prantl. Limestone adder's-tongue. Fig. 4. 

Plants resembling O. vulgatum, slender to somewhat stout, to 25 cm. tall; root- 
stock cylindric, erect, producing 2 to 3 or rarely more fronds in a single season, 
with long brown roots; common stalk to 10 cm. long, mostly below ground; 
sterile blade sessile or sheathing the stalk of the spike, mostly elliptic, acute and 
apiculate at apex, to 10 cm. long and 3.5 cm. wide; veins forming wide oblique 
areoles in which are included secondary veinlets that form secondary areoles; 
fruiting spike on a slender elongate stalk that is to 10 cm. long, cylindric, apicu- 
late, to about 3 cm. long and 4 mm. in diameter; sporangia to about 30 on each 
side of the rachis. O. vulgatum f. Engelmannii (Prantl) Clute. 

Usually found in large colonies in thin black soil on limestone barrens or ledges 
in seepy areas, rocky woodland slopes, in cedar brakes or in clayey soil along 
streams, occasionally invading pastures and old fields, rare in Okla., in Tex. gen- 
erally distributed and rather frequent in the Blackland Prairies, with a few sta- 
tions in the Timber Belt, uncommon in Ariz. (Cochise and Santa Cruz cos.); from 
Va. to cen. Fla., w. to s. 111., Kan. and Ariz.; also Mex. 

5. Ophioglossum vulgatum L. Common adder's-tongue. Fig. 9. 

Plants often tall and slender, to about 35 cm. tall; rootstock erect, nearly 
cylindric, bearing numerous fleshy roots and one to several fronds; common stalk 
to about 9 cm. long, half or more above ground; sterile blade sessile or sheathing 
the stalk of the spike, variable in shape, ovate to lanceolate or oblong-elliptic 
to oblanceolate, subtruncate to narrowly obtuse at the apex, to 12 cm. long and 

50 



5 cm. wide; venation regularly forming areoles without included secondary areoles; 
fruiting spike on a slender elongate stalk that is to 17 cm. long, compressed- 
cylindric, apiculate, to 4 cm. long and 3-5 mm. in diameter; sporangia to about 
30 on each side of the rachis. 

In moist open woods, meadows, alluvial woodlands and swamps, in Tex. rare in 
several cos. in the n. Timber Belt of e. Tex. and in Jefferson Co. in the Coastal 
Prairies, reported (fide Clausen) from Denton and Harris cos., reported from 
Ariz.; from P. E. I. and N. S., s. to Fla., w. to Ont., Tex. and (?) Ariz.; also 
Mex., Alas, and Euras. 

Fam. 7. Osmundaceae R. Br. Cinnamon Fern Family 

Large terrestrial to subaquatic plants of low moist soils and wet places with 
creeping to erect woody rhizomes, rarely arborescent, the roots hard and fibrous; 
fronds erect-spreading, occasionally as much as 18 dm. or more tall, clustered; 
stipes scaleless; blades bipinnatifid to bipinnate, rather coarse, uniform to entirely 
dimorphic or with some of the pinnae dimorphic, with the usually forked veins 
free and extending to the margins of the ultimate segments; sporangia in dense 
paniculate clusters, entirely replacing the vegetative tissue of certain pinnae or 
whole fronds, naked, large, globose, usually short-stalked, longitudinally cleft 
into two halves, with the ring or annulus few-celled or wanting; spores green. 

This family comprises three genera, the following and two Old World genera, 
that include about 20 species. 

1. Osmunda L. 

Rather coarse plants; fronds in a large crown from a woody rhizome, arranged 
in two circles, the inner circle fertile, erect and developing first, the outer circle 
sterile and spreading; blades wholly spore-bearing or with part of the pinnae 
spore-bearing either near the middle or at the apex, the spore-bearing tissue red 
or brown; sporangia short-stalked, densely clustered on the ultimate veinlets; 
spores copious, green. 

About 10 species, mostly in the north temperate regions of both hemispheres. 

1. Sterile blades pinnate-pinnatifid, the ultimate segments entire; fertile fronds 
separate, cinnamon-colored at maturity 1. O. cinnamomea. 

1. Sterile blades bipinnate, the pinnules serrulate; upper pinnae modified for 
spore production 2. O. regalis var. spectabilis. 

1. Osmunda cinnamomea L. Cinnamon fern. Fig. 10. 

Fronds several, erect, dimorphic, to 15 dm. tall; stipes irregularly coated with 
a loose cinnamon-colored tomentum; sterile blades lanceolate to oblong-lanceolate, 
acuminate, to 1 m. long and 35 cm. wide; pinnae opposite to subopposite, deeply 
pinnatifid, with a tuft of tomentum persisting at the base of each pinna; fertile 
blades succulent, nonfoliose, soon withering. 

Usually in moist or wet soil of swamps, marshes, on open or wooded seepage 
slopes, along streams, on the edge of lakes and bogs and occasionally on wet 
ledges in e. Okla. and in Tex. rather generally distributed in the Timber Belt, s. 
to Orange Co. in the Coastal Prairies, w. to Gonzales, Lee and Milam cos. in the 
Blackland Prairies, with a lone station in Uvalde Co. on the Edwards Plateau; 
throughout e. N. A. from Nfld. to Minn., s. to cen. Fla. and Tex. 

2. Osmunda regalis L. var. spectabilis (Willd.) Gray. Royal fern. Fig. 10. 
Fronds clustered, to 18 dm. tall; stipes slender, glabrous; blades broadly elliptic 

to oblong-ovate, with the lower 2 to 6 pairs of pinnae sterile, the upper pinnae 
transformed into fertile ones. 

51 




Fig. 10: 1 and 2, Osmunda cinnatnomea: 1, sterile and fertile fronds, x %; 2, 
longitudinal section of rhizome, x %. 3, Osmunda regalix var. spectahilis: 3, upper part 
of frond, x %. (From Correll in Lundell's Flora of Texas, Vol. 1, PI. 9). 



In swamps, marshes, moist woods, depressions in savannahs and prairies, on 
stream banks and seepage slopes, and in or on the edge of lakes in e. Okla., in 
Tex. generally distributed and common in the Timber Belt, s. and s.w. to Jefferson 
and Victoria cos. on the Coastal Prairies, w. to Travis Co. in the Blackland 
Prairies, adj. to the Edwards Plateau; from Nfld. to Sask., s. to Fla. and Tex.; also 
Berm., the W. I., Mex., C. A. and S. A. 

Fam. 8. Marsileaceae R. Br. Pepperwort Family 

Plants herbaceous, rooting in mud, creeping, often partly submerged, rarely 
floating, with slender branched rhizomes; leaves erect or floating, distichous, 
more or less remote, filiform or with long-petiolate 2- to 4-foliolate blades; leaflets 
(when present) of a cuneate type, with close dichotomous venation; sporocarps 
hard, bony, globose to ellipsoid, pilose or essentially glabrous, pedunculate, one 
to several borne on the rhizome near the base of the petiole or upon the petiole; 
sori solitary within the compartments, each producing both megaspores and 
microspores; megaspores germinate into prothallia that bear mostly archegonia; 
microspores germinate into prothallia that bear antheridia. 

This family comprises three genera containing more than 70 species that are 
found chiefly in the Old World. 

1. Leaf with distinct blade and petiole, the blade 4-foliolate 1. Marsilea 

1 . Leaves filiform, without distinct blades, the tips uncoiling as the plant matures 
2. Pilularia 

1. Marsilea L. Water Clover 

Small plants forming dense colonies; leaves long-petiolate, with cruciform 
(4-foliolate) blades; sporocarps subglobose to ellipsoid, mostly with 2 teeth near 
the base, commonly provided with coarse or paleaceous hairs, splitting into 2 
valves at maturity and emitting numerous sori on a gelatinous receptacle; sori 
including both megasporangia and microsporangia. 

About 60 species of wide distribution, mainly in the Old World. 

The plants of some species provide shade and shelter for fish, and the sporo- 
carps are known to be eaten by ducks. 

1. Sporocarps several on a special branch or from a common peduncle (2) 

1. Sporocarps solitary, with paleaceous hairs or naked; leaves and petioles naked 

or sparsely pubescent (3) 

2(1), Leaflets (and petioles) with long loose hairs, without colored stripes; 
sporocarps densely covered with reddish hairs that are to 3 mm. 
long 1. M. macropoda. 

2. Leaflets (and petioles) essentially glabrous, usually developing (with age) 

reddish-brown stripes on the lower surface; sporocarps losing (with 
age) its light-brown hairs 2. M. mexicana. 

3(1). Leaflets flabeflate to broadly cuneate (4) 

3. Leaflets narrowly and obliquely cuneate to cuneate-oblanceolate (5) 

4(3). Rhizome without conspicuous fascicled branches; peduncle usually very 
short, often scarcely as long as the sporocarp, usually free from 
the petiole or attached at its very base; sporocarp with rather 
long coarse reddish hairs 3. M. mucronata. 

4. Rhizome producing fascicled branches that are paleaceous at their tips; 

peduncle about twice the length of the sporocarp or more, usually 
attached above the base of the petiole; sporocarp sparsely provided 
with short coarse hairs 4. M. uncinata. 

53 




Fig. 11: Marsilea mucronata: a, habit, terrestrial plant, with densely pubescent 
leaves and petioles, arising from slender rhizomes, x \\{,; b, leaf detail, terrestrial plant, 
X 21/2; c, habit, terrestrial plant showing sporocarps, x %; d, sporocarp, terrestrial plant 
showing dense pubescence, x 4; e, habit, aquatic plant with elongate slender completely 
submersed petioles, their glabrous leaf blades floating, x %; f, leaf detail, aquatic plant, 
X 2V2; g, sporocarp, aquatic form, showing blunt teeth near junction with stalk, x 4. 
(From Mason, Fig. 4.). 



5(3). Leaflets usually more than 10 mm. long, truncate and typically irregularly 
toothed at apex 5. M. tenuifolia. 

5. Leaflets less than 8 mm. long, lightly rounded to subtruncate and entire at 
apex 6. M. Fournieri. 

1. Marsilea macropoda Engelm. ex A. Br. Fig. 9. 

Plants robust, 10-25 cm. tall, forming large mats, adorned with bright red- 
dish hairs at the tips of the branches of the subglabrous rhizomes; petioles slender, 
with long shaggy hairs; leaflets large, broadly cuneate, entire, usually undulate, 
clothed on both side with long lax whitish hairs (especially when young), becom- 
ing less pubescent with age, to 5 cm. long and 2 cm. wide; sporocarps 2 to 6 on 
erect or ascending branched peduncles that are 2—3 cm. long, obliquely obovate, 
densely villous with the reddish hairs to 3 mm. long or more, 6-8 mm. long, 5-6 
mm. in diameter, the raphe short, lower tooth obtuse, upper tooth inconspicuous 
or wanting; sori 10 in each valve. 

In mud or sandy soil and water of swamps, marshes, woodland bogs, ditches, 
streams, and on the edge of ponds and lakes, apparently endemic to Tex. where 
it is widespread and rather frequent in the Rio Grande Plains, n. and e. to 
Jackson Co. in the Coastal Prairies, Travis Co, in the Blackland Prairies, and 
in the cos. bordering the Edwards Plateau. 

The several sporocarps borne on each peduncle and the large hairy leaflets are 
characteristics that readily distinguish this species. 

2. MarsUea mexicana A. Br. Fig. 4. 

Plants to 2 dm. tall or more; rhizomes slender, widely creeping and much- 
branched, greenish-brown to light-brown; petioles filiform, channeled, glabrous, 
to about 18 cm. long; leaflets broadly cuneiform or obovate-flabellate, rounded 
and slightly undulate at apex, 1—1.5 cm. long, green, typically marked with 
reddish-brown stripes (or glands?) parallel with the veins on the lower surface, 
glabrous or sometimes with a few hairs near base; peduncle (free part) approxi- 
mately as long as the sporocarp or slightly longer, pubescent at first; sporocarps 
not scattered but densely clustered on special branchlets that also give rise to slender 
terete rigid rootlike structures, obovoid to ellipsoid, about 4 mm. long, somewhat 
compressed laterally, dark-colored, at first covered with matted light-brown hairs 
and terminated with long dark-brown hairs that are deciduous with age, the 
raphe and basal tooth obsolescent; sori approximately 12 or 13 in each sporocarp. 

In shallow water or on mud flats of pools and ponds in Aransas Co. on the 
Tex. coast; from Tex. and Mex., s. to Hond. 

This species is distinctive in that at least some of its leaflets have reddish- 
brown stripes, or possibly glands, on their lower surface parallel with the veins. 
Also, the sporocarps are borne in clusters on modified branchlets that also give 
rise to terete, rigid, rootlike structures that possibly might be considered as 
rhizophores. 

3. Marsilea mucronata A. Br. Hairy pepperwort. Figs. 9 and 11. 

Plants 6-20 cm. tall; rhizomes slender, widely creeping, branched but without 
conspicuous fascicled branches; petioles filiform, to 18 cm. long; leaflets spreading, 
spatulate to obovate, truncate to rounded and entire or somewhat toothed at the 
apex, sparsely pubescent (especially beneath) with short and broad appressed 
hairs, to 15 mm. long, about as wide as long; peduncles free, axillary at base 
of leaves or from the very base of the petiole, ascending, usually very short, mostly 
scarcely as long as the sporocarp; sporocarps solitary, oval to ellipsoid, slightly 
oblique and compressed, purplish punctate, coarsely strigose-pubescent with red- 
dish hairs, to 8 mm. long, usually much smaller, 3-6 mm. in diameter, the raphe 

55 



short, the upper tooth only slightly curved, lower tooth blunt and shorter than 
the upper tooth; sori 6 to 11 in each valve. M. vestita of auth. 

Usually in black waxy mud along streams and rivers, in and about ponds, in 
silt of lakes, and in ditches or depressions such as old buffalo wallows in prairies 
that are periodically inundated, our most widespread Marsilea occurring through- 
out Okla. and in every section of Tex. but the Timber Belt, most frequent and 
abundant in the Blackland Prairies and on the Edwards Plateau, through N.M. 
(Lea and Sierra cos.) to Ariz. (Navajo, Coconino, Yavapai, Pinal, Cochise and 
Pima COS.); from s. Sask. and Alta., s. to Tex., N.M., Ariz., Calif, and Coah. e. 
to Fla. 

Some plants of M. mucronata closely resemble those of M. macropoda, with 
which they are occasionally confused. The solitary sporocarp, however, readily 
distinguishes them from that species. 

Although a temporary pool in which this species may occur may become 
powdery dry in season, the bony sporocarps remain undamaged until water again 
makes the depression a quagmire. 

4. Marsilea uncinata A. Br. Fig. 9. 

Plants 6-20 cm. tall; rhizomes slender, filiform, producing fascicled branches 
that are paleaceous at their tips; petioles filiform, to 19 cm. long; leaflets spread- 
ing, obovate to broadly flabellate, subtruncate to rounded at the apex, entire, to 3 
cm. long, about as wide as long, glabrous to sparsely strigose-pubescent; peduncles 
usually attached to the petioles above their base, about twice or more the length 
of the sporocarps, 1.5-3 cm. long; sporocarps subglobose to ellipsoid, more or less 
covered by short coarse reddish hairs, 4-8 mm. long, 3-6 mm. in diameter, the 
raphe long, upper tooth longer than the lower tooth and mostly uncinately 
curved; sori 13 or 14 in each valve. 

In or on the edge of permanent ponds, along spring branches and in shallow 
water of brooks, ditches and bayous, rather generally distributed but uncommon 
in the Blackland Prairies and in several isolated localities in every section of Tex. 
except the Timber Belt; apparently confined to Tex. and La. 

This species, unlike M. mucronata and M. tenuifolia, apparently needs a con- 
stant supply of water for optimum development, if not for survival. 

A characteristic that superficially separates this species from the closely allied 
M. mucronata is the usual attachment of the long peduncle to the leaf petiole 
above its base. The much shorter peduncle of M. mucronata is usually either free 
from, in the axil of, or from the very base of the leaf petiole. 

5. Marsilea tenuifolia Engelm. ex Kunze. Fig. 9. 

Plants slender, 5-17 cm. tall; petioles glabrous or essentially so; leaflets narrowly 
cuneate, truncate and usually irregularly toothed at apex, more or less falcate, 
villous with appressed hairs, to 25 mm. long, 2—8 mm. wide; sporocarps on short 
slender peduncles, with divergent subequal teeth, 5-8 mm. long, 4—5 mm. in 
diameter; sori 9 to 11 in each valve. M. vestita var. tenuifolia (Engelm.) Underw. 
& Cook. 

On the edge of lakes, in shallow beds of creeks, and in periodically inundated 
depressions, especially in old buff"alo wallows, in Tex. rare on the Edwards Pla- 
teau, in Travis Co. in the Blackland Prairies and in the s. part of the Plains 
Country; apparently confined to Tex. and Okla. (unverified). 

The narrowly cuneate leaflets with usually irregularly toothed apex are distinc- 
tive of this species. 

6. Marsilea Fournieri C. Chr. Fig. 4. 

Plants small, usually about 8 cm. tall or less, villous throughout; rhizome stout 
for the plant, compact and sometimes sending off short thick branches; petioles 

56 



filiform, to about 7 cm. long, villous but eventually glabrescent; leaflets asym- 
metric, cuneate-oblanceolate to cuneate-obovate or linear-oblanceolate, sub- 
truncate to lightly rounded at the entire apex, about 7 mm. long, villous; peduncle 
shorter than the sporocarp; sporocarps crowded, broadly ellipsoid to suborbicular- 
oval, lightly compressed, invested with brownish hairs that soon turn grayish and 
are eventually deciduous, about 4 mm. long, the raphe short and blunt, the upper 
tooth sharp and prominent; sori 15, with 4 to 7 white sporangia in each sorus. 

In wet places or depressions such as playa lakes that are periodically inundated, 
rare in N.M. (Lea Co.), more frequent in Mex. (Coah., Chih., S.L.P. and Jal.); 
to be expected in Tex. 

2. Filuiaria L. Pillwort 
Six widely distributed species. 

1. Pilularia americana A. Br. American pillwort. Fig. 7. 

Very small inconspicuous plants of muddy situations, with slender wide-creeping 
rhizomes bearing at the nodes one to several leaves, forming dense mats; leaves 
setiform, solitary or sometimes several together from the nodes, glabrous, 2-6 cm. 
long, rarely to 1 dm. long; sporocarps produced just below surface of ground, 
axillary, pedunculate, globose, brownish-yellow, 2-3 mm. in diameter. 

In shallow temporary muddy pools on rock flats and depressions in clayey 
prairies and in mud on edge of lakes, in our region only in Comanche Co. in s. w. 
Okla. and in Burnet Co. on the Edwards Plateau in Tex.; from s. Calif, to Ore.. 
also isolated in s.-cen. Kan., w. Ark. and cen. Ga. 

Fam. 9. Salviniaceae Dum. Salvinia Family 

Plants minute or small, aquatic, free-floating or on mud, with a branched 
rhizome bearing simple roots (Azolla) or essenti&l'v stemless with some of the 
leaves modified as roots (Salvinia); leaves 2-ranked or in whorls, opposite or 
alternate, simple or lobulate; sporocarps soft, thin-walled, borne singly or two or 
more on a common stalk at the base of the leaves, 1 -celled, with a central often 
branched receptacle, unisexual, bearing either megasporangia containing a 
solitary megaspore or microsporangia containing numerous microspores; massulae 
within macrosporangia bearing septate or non-septate glochidia with barbed tips; 
megaspores germinate into prothallia bearing archegonia; microspores germinate 
into prothallia bearing antheridia. 

This family comprises 2 genera of wide distribution — Salvinia and Azolla with 
about 16 species. 

1. Azolla Lam. Water Fern. Mosquito Fern 

Minute reddish or green free-floating plants, occasionally on mud, mostly 
densely matted and resembling some species of liverworts, with the stems pinnately 
branched and concealed by pendent roots and imbricating leaves; leaves distichous, 
2-lobed, with the upper lobe floating and the lower lobe submersed; sporocarps 
borne in one or two pairs on the lower leaf lobe. 

This genus consists of about 6 species of wide distribution. 

The dense cover often formed by these plants over the surface of ponds and 
lagoons provides shade and shelter for fish. The plants are incidentally eaten by 
ducks and other wild fowl. 

A compound microscope is needed in order to identify species in this genus 
with any certainty. 

57 



1. Glochidia with several scattered septa; basal portion of the megaspore pitted; 
plant usually more than 1 cm. in diameter; leaves 0.7 mm. long or 
more, closely imbricate 1. A. mexicana. 

1. Glochidia without septa or rarely with 1 or 2 septa mostly just beneath the 

tip (2) 

2(1). Plants elongate, 2 cm. long or more; leaves oblong to ovate, closely ap- 
pressed and imbricate, papillose, about 1 mm. long; basal portion 
of the megaspore tesselate-reticulate 2. A. filiculoides. 

2. Plants small, to 1 cm. in diameter; leaves suborbicular, divaricate, nearly 

smooth, about 0.5 mm. long; megaspore unknown 

3. A. caroliniana. 

1. Azolla mexicana Presl. Fig. 12. 

Plants flattened, dichotomously branched, 1-3 cm. in diameter; upper leaf 
lobes imbricated, somewhat irregular in shape, usually broadly rhombic-ovate to 
suborbicular, broadly rounded to obtuse at apex, mostly less than 1 mm. long, 
usually profusely tinged purplish-cerise, papillose, with narrow hyaline cellular- 
papillose margins, under leaf lobes usually much larger than the upper ones; 
microsporangia usually with 4 massulae; megaspores pitted on the basal portion; 
glochidia of massulae always septate. 

Floating on surface of lakes and ponds and in quiet waters of streams and 
irrigation canals in the Rio Grande Valley of s. Tex. and in N.M.; from s. Tex., 
Calif, and Mex., s. to n. S.A., n. to Ut., B.C., Wise, and 111. 

2. Azolla 'filiculoides Lam. Fig. 12. 

Plants elongate, dichotomously branched, 2-6 cm. long; upper leaf lobes closely 
appressed, imbricated, minutely papillose, oblong to ovate, obtuse at apex, about 
1 mm. long, with rather broad thin hyaline margins that are usually only slightly 
cellular-papillose, brownish and somewhat sparingly tinged with red; under leaf 
lobe about as large as the upper one; microsporangia with 4 to 6 massulae; 
megasporangia with the basal portion tesselate-reticulate; glochidia of massulae 
not septate or rarely septate only at the apex. 

In fresh-water ponds and ditches in Ariz. (Pima, Santa Cruz, Mohave and 
Yuma cos.) ; from Alas, to Guat.; also S.A., Eur. and H.I. 

3. Azolla caroliniana Willd. Fig. 13. 

Plants forming floating mats to 3 cm. across; leaves minute, deeply bilobed, 
imbricate, mostly with hyaline margins, to 0.9 mm. long and 0.6 mm. wide, the 
upper emersed lobes oval or suborbicular-quadrate, deep-green to purplish-red, 
somewhat convex, hollow, provided with numerous 2-celled hairs, the lower sub- 
mersed lobes glabrous, larger and paler than the upper lobes. 

On still water of swamps, ponds, lakes and in slow-moving water of streams 
and resting on mud, up to 5,500 ft. alt., Okla. (McCurtain Co.) and in Tex. 
sporadically distributed from Wood Co. in the n.e. Timber Belt, s. to Orange 
Co. on the Coastal Prairies and Cameron Co. in the Rio Grande Plains, w. to 



Fig. 12: Azolla. a-e, A. mexicana: a, part of a fertile plant: (left) globose micro- 
sporocarp with megasporocarp at its base, (right) pair of megasporocarps enclosed in 
one indusium (uncommon), x 20; b, habit, top view, x 12; c, septate glochidia of 
microsporia massulae, x 100; d, microsporic massula, x 40; e, megaspore covered by 
tip of indusium, X 40. f-1, A. filiculoides: f, megaspore covered by tip of indusium, 
X 40; g, young stalked microsporangia, showing a few glochidia of the massulae pro- 
truding from ruptured wall, 40; h, separating massulae, x 40; i, nonseptate glochidia, 
X 100; j, microsporocarp containing a large number of microsporangia (from same 
plant as k), x 20: k, part of fertile plant viewed from below and showing the roots 
and a small microsporocarp with a megasporocarp at its base, x 20; 1, separating 
massulae, x 40. (From Mason, Fig. 6.). 

59 




Fig. 13: Azolla caroliniana: all greatly magnified, a, habit, upper surface of sterile 
plant; b, lower surface, plant with microsporocarps; c, microsporocarp; d, micro- 
sporangium with massula being discharged; e, glochida types from a single massula; 
f, one branched glochidium: g, tip of glochidium highly magnified; h, the two-lobed 
leaf. (From R. K. Godfrey et al. Am. Fern Journ., Vol. 51, p. 90, 1961). 



Jeff Davis and Presidio cos. in the Trans-Pecos, reported from N. M. (Sierra Co.); 
from Fla. w. to Tex., N.M. (?) and Okla., n. to N. C, O. and Alas.; also the W. I. 
and Mex. to Patagonia. 

Fam. 10. Polypodiaceae S. F. Gray True Fern Family 

Usually large terrestrial or epiphytic plants of diverse habits with short or 
elongate creeping to suberect rhizomes; fronds clustered or remote, pendent to 
erect-spreading, commonly stalked, occasionally dimorphic; blades simple to 
much decompounded and variously dissected, with the veins simple to mostly 
forked, free or united and forming areoles with or without included veinlets; 
sporangia long-stalked, provided with an incomplete vertical annulus and open- 
ing transversely, borne either upon the veins on the lower surface or near the 
margins of ordinary leaf blades in lines or clusters (sori), occasionally borne on 
wholly fertile fronds or on partially sterile blades; sori naked or covered by a 
membrane (indusium) that develops from either the vein or modified leaf-margin; 
prothallia green. 

This family, that includes about 50 genera and several thousand species, is by 
far the largest family of ferns in that it includes more than two thirds of the 
living ferns. They are found throughout the world from arctic to tropical regions 
in dense rain forests to desert areas. 

1. Blades simple, pinnatifid or once-pinnate; pinnae or primary divisions entire, 
toothed or pinnatifid (2) 

1. Blades twice-pinnate or more dissected (7) 

2(1). Primary divisions or pinnae with the margins entire, undulate, irregularly 
toothed or incised, never distinctly pinnatifid (3) 

2. Primary divisions or pinnae distinctly pinnatifid (4) 

3(2). Primary segments with entire to undulate margins; sterile blade with the 
pinnae commonly opposite or essentially so; sporophylls with the 
divisions tightly rolled together, beadlike 2. Onoclea 

3. Primary segments with serrulate margins; sterile blades with the pinnae com- 

monly alternate; sporophylls with the divisions narrowly Hnear 

4. Lorinseria 

4(2). Sori orbicular to reniform-orbicular (5) 

4. Sori linear to elliptic, never orbicular (6) 

5(4). Acicular unicellular hairs present on the costae above; segments of the 
fronds ciliate; stipe bundles 2, these united below the base of the 
blade; rhizome scales ciliate (sometimes sparingly so); rhizomes 
slender, mostly creeping; fronds membranous, mostly deciduous; 
veins reaching the margin 6. Thelypteris 

5. Acicular hairs absent on the costae above; segments of the fronds not ciliate; 

stipe bundles 3 to 7, free to above the base of the blade; rhizome 
scales not ciliate, sometimes toothed; rhizomes massive, short- 
creeping to erect; fronds herbaceous to coriaceous, sometimes ever- 
green; veins ending short of the margin in elongate hydathodes 

7. Dryopteris 

6(4). Sori parallel to and contiguous to the midrib of the leaf segments on 
specialized veins 3. Woodwardia 

6. Sori borne obliquely to and away from the midrib of the leaf segments on 

ordinary veins 5. Athyrium 

7(1). Sori borne on the under surface of the recurved portion of the ultimate 
segments; blades with only the apical margin of the ultimate seg- 
ments recurved 1. Adiantum 

61 




Fig. 14: 1 and 2, Adiantum Capillus-Veneris: 1, frond and rhizome, x %; 2, fertile 
pinnule, x 3. 3-5, Adiantum tricholepis: 3, pinna, x %; 4, fertile segment, x 3; 5, erect- 
ascending rhizome, x %. (From Correll in Lundell's Flora of Texas. Vol. 1, PI. 13.). 



7. Sori not borne on the under surface of a recurved marginal lobule but on the 

leaf surface under a recurved marginal lobule (when this is pres- 
ent) (8) 

8(7). Sori linear-elliptic; indusia curved and crescentiform 5. Athyrium 

8. Sori round; indusia not curved or crescentiform (9) 

9(8). Acicular unicellular hairs present on the costae above; segments of the 
fronds ciliate; stipe bundles 2, these united below the base of the 
blade; rhizome scales ciliate (sometimes sparingly so); rhizomes 
slender, mostly creeping; fronds membranous, mostly deciduous; 
veins reaching the margin 6. Thelypteris 

9. Acicular hairs absent on the costae above; segments of the fronds not ciliate; 

stipe bundles 3 to 7, free to above the base of the blade; rhizome 
scales not ciliate, sometimes toothed; rhizomes massive, short- 
creeping to erect; fronds herbaceous to coriaceous, sometimes ever- 
green; veins ending short of the margin in elongate hydathodes 

7. Dryopteris 

1. Adiantum L. Maidenhair Fern 

Delicate terrestrial or rock-inhabiting plants of moist wooded slopes, ravines 
and stream banks, with slender creeping to short and ascending scaly rhizomes; 
fronds suberect to pendent, distichous or in several ranks; stipes slender, strong, 
usually blackish and lustrous, glabrous or rarely pubescent, scaly at base only; 
blades pedately or pinnately decompound, variously dissected, rarely simple; ulti- 
mate segments oblique, petiolate or subsessile, articulate and deciduous in some 
species, membranous to subcoriaceous, mostly glabrous, with veins free and 
forking or rarely anastomosing; sori borne along or rarely between the ends of 
the ultimate veins, appearing marginal on the back of the reflexed apex of the 
lobules of the pinnules or ultimate segments; indusia formed in part by the re- 
flexed margins of the lobules. 

About 200 species, mainly in tropical America. Many species are cultivated. 

1. Fronds smooth; ultimate segments obovate-cuneate or rhombic, usually promi- 
nently incised 1. A. Capillus-Veneris. 

1. Fronds pilose with whitish hairs; ultimate segments suborbicular, not promi- 
nently incised 2. A. tricholepis. 

1. Adiantum Capillus-Veneris L. Culantrillo. Fig. 14. 

Rhizomes horizontal, creeping, cordlike, laxly scaly; rhizome scales thin, light- 
brown, hnear-lanceolate, attenuate, entire; fronds numerous, clustered or scattered 
along the rhizome, laxly ascending to pendulous, 13-7 dm. tall; stipes reddish- 
brown to purplish-black, lustrous, sulcate, glabrous, mostly shorter than the 
blades; blades broadly ovate to lanceolate, attenuate at apex, bipinnate to tripinnate 
or occasionally quadripinnate, glabrous, 1.5-4 dm. long, to 3.5 dm. wide; pinnae 
alternate, laxly spreading, petiolate, to 18 cm. long; ultimate segments numerous, 
petiolulate, not jointed, membranous to thin-herbaceous, bright-green, variable in 
size and shape, obliquely obovate to semiorbicular, truncate to obliquely cuneate 
at the base, the outer margin more or less incised or deeply lobulate, 7-30 mm. 
long, about as wide as long; sterile segments regularly denticulate with the teeth 
acute to long-acuminate; sori borne on the margins of the lobules of the ultimate 
segments, somewhat lunate; modified indusial margin of the lobules glabrous, 
prominent, scarious, with crenate margins. A. modestum Underw., A. tricholepis 
f. glabrum Clute. 

Limestone rocks, ledges and cliffs, especially along streams and about pools in 
canyons and ravines, rare in Okla., in Tex. frequent on the Edwards Plateau and 
in the Trans-Pecos, e. to Harris Co. on the Coastal Plain and s.w. to Zavala Co. in 

63 




Fig. 15: 1 and 2, Onoclea sensibilis: 1, plant with fertile and sterile fronds, x %: 
2, details of upper portion of sterile segment, x 2. 3-5, Lorinseria areolata: 3, plant 
with fertile and sterile fronds, x W, 4, section of segment with son, x 2; 5 details 
of upper portion of sterile segments, x 2. (From Correll in Lundell's Flora of Texas, 
Vol. 1,P1. 28). 



the Rio Grande Plains, with a few stations in the Blackland Prairies and n.-cen. 
Plains Country, westw. through N.M. (throughout most of the state) to Ariz.; 
from Va., s. to Fla., w. to Ky., Tenn., Mo., Ariz, and Mex. to n. S. A.; also 
Euras. 

2. Adiantum tricholepis Fee. Hairy maidenhair fern. Fig. 14. 

Rhizome short, stout, erect or ascending, scaly; rhizome scales deep reddish- 
brown, narrowly lanceolate, attenuate and usually terminated by an early fugacious 
contorted seta at the apex, ciliolate; fronds several, cespitose, erect-recurved to 
pendulous, to 7 dm. tall or more; stipes smooth, vernicose, deep reddish-brown 
to blackish, to 3 dm. long or more; blades oval to ovate in outline, bipinnate to 
quadripinnate, pilose throughout with whitish hairs (especially on the veins be- 
neath), 2-4 dm. long, 1.5-3.5 dm. wide; pinnae alternate, suberect to horizontal, 
petiolate, to 2 dm. long; ultimate segments small, numerous, petioled, membra- 
nous to rigidly herbaceous, orbicular-rhombic, subentire to obscurely tricrenate at 
the broadly rounded apex, truncate to broadly cuneate at the base; sori 3 to 10, 
marginal; modified indusial margin of the ultimate segments inconspicuous, 
pubescent, scarious, with undulate margins. 

On moist limestone cliffs along wooded streams on the Edwards Plateau in Tex.; 
uncommon in Tex., Mex. and Guat. 

This species is not as dependent upon a continuous, permanent source of water 
as is /i. Capillus-Veneris. It is, however, occasionally found in seepage areas. Our 
only other species, A. pedatum L., is definitely a terrestrial with erect fronds. 
It is usually found in rich, moist, loamy soil. 

2. Onoclea L. Sensitive Fern 
A monotypic genus, native in the Northern Hemisphere. 

1. Onoclea sensibilis L. Fig. 15. 

Coarse herbaceous plant with slender branching rhizome to about 7 mm. thick 
and copiously rooting and with few light-brown elliptic fugacious scales; fronds 
conspicuously dimorphic, erect-ascending, scattered along the rhizome; stipes 
slender, greenish or tinged with brown; sterile frond to 13 dm. high, glabrous, 
thin-herbaceous, withering with frost; blades broadly triangular, deeply pinnati- 
fid, the rachis winged; pinnae few, subopposite (especially the lowermost pinnae), 
oblong-lanceolate to elliptic-lanceolate, obtuse to acute, entire to undulate or the 
lower and sometimes the middle pinnae sinuately lobed; veins freely anastomos- 
ing; fertile frond to 8 dm. high, rigidly erect, persistent over winter; blades bipin- 
nate, with the pinnae much-contracted; pinnules rolled into close berrylike bodies 
(sporangia) and forming a narrow close panicle. 

In swamps, open flooded woodlands, meadows, sandy bogs, thickets along 
streams and about lakes, and on seepage slopes, in e. Okla. and in Tex. widespread 
and rather frequent in the Timber Belt s. to Jefferson Co. in the Coastal Prairies, 
w. to apparently disjunct stations in Burnet Co. on the Edwards Plateau and 
Wilson Co. in the Rio Grande Plains; from Nfld. to Ont., Minn, and S.D., s. to 
n. Fla. and Tex. 

3. Woodwardia Sm. Virginia Chain Fern 
About 12 species found mainly in the temperate regions of both hemispheres. 

1. Woodwardia virginica (L.) Sm. Fig. 16. 

Rather large coarse terrestrial plants; rhizome woody, ropelike, creeping- 
elongate and branching, black, to about 2 cm. thick, naked to densely chaffy 
(especially at apex) with brownish broadly lanceolate scales; fronds erect- 
ascending, uniform, borne at intervals along the rhizome, 4-15 dm. high; stipes 

65 




Fig. 16: Woodwardia virginica: 1, frond and rhizome, x Vx, 2, segment showing 
sori, X 3. (From Correll in Lundell's Flora of Texas, Vol. 1, PI. 29). 



black to chestnut-brown at the base, green or reddish-brown above, glabrous, 
lustrous, 3-9 dm. long; blades broadly ovate to oblong-elliptic or elliptic-lanceolate, 
bluntly acute, pinnate-pinnatifid, subcoriaceous, 3-6 dm. long. 12-30 cm. wide; 
pinnae linear-lanceolate to elliptic-lanceolate, acuminate, with small brown scales 
along the midrib, 7.5-15 cm. long, 12-35 mm. wide, deeply pinnatifid; ultimate 
segments obliquely ovate to oblong-lanceolate, obtuse to acute, 5-6 mm. wide, 
with the margins somewhat reflexed; sori double, contiguous to confluent, borne 
on the transverse veins forming the outer side of the areoles, oblong-linear, 
chainlike. Anchistea virginica (L.) Presl. 

In sphagnous bogs, swamps, moist thickets and meadows, and along streams, 
rather generally distributed in Tex. in the Timber Belt and in the extreme s.e. 
border cos. in the Coastal Prairies, w. to Gonzales, Lee and Milam cos. in the 
Blackland Prairies; from Fla. to Tex., n. to N.S., Ont. and 111.; also Berm, 

4. Lorinseria Presl Chain Fern 
A monotypic genus. 
1. Lorinseria areolata (L.) Presl. Fig. 15. 

Slender herbaceous plants; rhizomes slender, widely creeping, chaffy with brown 
ovate-lanceolate to lanceolate scales, to 4 mm. thick; fronds dimorphic, scattered 
on the rhizome; sterile fronds spreading, to 75 cm. high; stipes slender, greenish 
or stramineous, sometimes purplish-brown toward the base, 15-35 cm. long; blades 
ovate-oblong to ovate-deltoid, acuminate, usually deeply pinnatifid, sometimes 
pinnate below, membranous, 1.5-4 dm. long; ultimate segments alternate, linear- 
lanceolate to oblong-lanceolate, acute to acuminate, lightly or sometimes deeply 
sinuate, serrulate, usually connected by wings on the rachis or the lower pairs 
free, to 13 cm. long and 2 cm. wide, the veins joined in the numerous hexagonal 
areoles; fertile fronds erect, usually surpassing the sterile ones; stipes stout, 
purplish-brown, lustrous, 3-6 dm. long; blades ovate-oblong, obscurely pinnatifid 
or pinnate, 1.5-3 dm. long; pinnae alternate, distant, linear, often connected by a 
slight wing along the rachis, mostly. less than 5 mm. wide; sori linear to elliptic, 
in a single row on each side of the midrib. Woodwardia angustifolia Sm., W. 
areolata (L.) Moore. 

In sandy bogs and low sandy woods, swamps, marshes, thickets, on seepage 
slopes and along streams in s.e. Okla. and in Tex. generally distributed and rather 
frequent in the Timber Belt s. to Jefferson Co. in the Coastal Prairies and Bastrop 
and Gonzales cos. in the Blackland Prairies; from Fla. to Tex., Okla., Ark. and 
Mo., n. to N.S. and Mich. 

5. Athyrium Roth Lady Fern 

About 200 species that are in tropical and subtropical regions throughout the 
world. 

1. Athyrium Filix-femina (L). Roth var. asplenioides (Michx.) Farw. Southern 

LADY FERN. Fig. 17. 

Rather large terrestrial plant; rhizome shortly creeping, with light-brown scales, 
about 7 mm. in diameter; fronds clustered, to 12 dm. high; stipes yellowish-green, 
often tinged with red or brown, stramineous when dry, sparingly scaly below; 
blades ovate-lanceolate to elliptic-lanceolate, acuminate, pinnate-pinnatifid to 
rarely subtripinnate (at least below), thin-herbaceous to subcoriaceous, essen- 
tially glabrous throughout, usually exceeding the length of the stipe, to 35 cm. 
wide; pinnae shortly stalked, elliptic-lanceolate to narrowly lanceolate, acuminate, 
spreading horizontally or curved-ascending with age, to 4 cm. wide; pinnules or 
ultimate segments mostly decurrent on the rachis, sometimes subpetiolate, oblong- 
lanceolate, obtuse to shortly acuminate, incised to serrate or lobulate with the 

67 




^ 



Fig. 17: Athyrium FUix-femina var. asplenioides: 1, plant, x %; 2, pinnule with sori, 
X 3. (From Cornell in Lundell's Flora of Texas. Vol. I, PI. 31). 



lobules often again toothed; sori short, 3 to 10 pairs in each segment; indusia 
mostly curved, with gland-tipped cilia. A. asplenioides (Michx.) Eat. 

In sandy bogs, moist sandy woods, swamps, wet thickets and on stream banks 
in s.e. Okla. and in Tex. generally distributed and rather common in the Timber 
Belt and in several n. border cos. in the Coastal Prairies, w. to Williamson Co. 
in the Blackland Prairies; from Fla. to Tex., n. to e. Mass., Ind. and Mo. 

Var. californicum Butters. Characterized by its dark scales, indusia short ciliate 
or merely toothed, and large spores with a distinct, wrinkled and reticulate 
exospore. 

In habitats similar to those of var. asplenioides in N.M. (Socorro, Grant, San 
Miquel and Rio Arriba cos.) and Ariz. (Apache, Graham, Cochise and Pima cos.); 
Ida. and w. Wyo., s. to N.M., Ariz, and Calif. 

6. Thelypteris Schmid. 

Terrestrial plants of moist woodlands and rocky places, with stout or mostly 
slender strong long-creeping sparsely scaly rhizomes; scales of the rhizome ciliate, 
entire, fibrous; fronds erect-ascending, somewhat distant, deciduous; stipes stra- 
mineous, essentially scaleless, with two bundles at the base; blades uniform, thin- 
membranous, bipinnatifid to pinnate-pinnatifid or bipinnate-pinnatifid, pubescent 
with acicular unicellular hairs on the costae above, rarely sparsely scaly; ultimate 
segments usually entire or nearly so, rarely serrate or coarsely toothed, ciliate; 
veins few, simple or once-forked, reaching the margins; sori dorsal on the veins, 
median or supramedial; indusia small or sometimes absent, reniform, usually 
glandular or ciliate. 

A large world-wide genus of several hundred species that attains its optimum 
development in temperate and subtropical Asia. 

1. Ultimate segments with the margins serrate or coarsely toothed 

1, T. Torresiana. 

1. Ultimate segments with the margins entire to crenate or nearly pinnatifid, never 

serrate nor toothed ( 2 ) 

2(1). Blades strongly triangular, pinnatifid (the rachis winged throughout); 
indusia wanting 2. T. hexagonoptera. 

2. Blades lanceolate to elliptic-lanceolate or sometimes ovate-lanceolate, pinnate; 

indusia present (3) 

3(2). Veins of ultimate segments once- or twice-forked; indusia glabrous 

3. T. palustris var. Haleana. 

3. Veins of ultimate segments simple; indusia variously pubescent (section Cyclo- 

sorus) (4) 

4(3). Basal veins of adjacent segments united below the sinus with an excurrent 
vein leading toward the sinus; costules, veins and often lamina 
above hairy (5) 

4. Basal veins of adjacent segments free below or connivent at the sinus; costules, 

veins and lamina above with or without hairs (6) 

5(4). Costae below with predominately short hairs which are uniform in length 
(less than 0.2 mm. and often less than 0.1 mm. long); excurrent 
veins mostly greater than 2 mm. long; stipe purplish; frond with 

usually more than 2 pairs of greatly reduced pinnae at the base 

4. T. dentata. 

5. Costae below with most hairs greater than 0.3 mm. long with some exceeding 

0.5 mm.; excurrent veins less than 2 mm. long; stipe stramineous; 

fronds with to 2 pairs of reduced pinnae at the base 

5. T. quadrangularis var. versicolor. 

69 




Fig. 18: 1 and 2, Thelypteris normalis: 1, frond and rhizome, x %; 2, segments 
with sori, x 3. 3, Thelypteris dentata: 3, segments with sori, x 3. 4, Thelypteris Tor- 
resiana: 4, pinna (x %) and segments with sori, x 3. (From Correll in Lundell's Flora 
of Texas, Vol. 1, PI. 34). 




Fig. 19: 1 and 1, Thelypteris hexagonoptera: 1, frond and rhizome, X %; 2, seg- 
ment with sori, X 3; 3a-3c, Thelypteris palustris var. Haleana: 3a, pinna, X %; 3b, 
sterile segment, X 3; 3c, lower surface of fertile segment, X 3. 4-5b, Cvstopteris 
jragihs var. protrusa: (not usually considered a wetland plant) 4, frond and rhizome, 
X %; 5a, segment with sori, X 3; 5b, sorus, X 25. (From Correll in Lundell's Flora 
of Texas, Vol. 1, PI. 35). 



6(4). Costae, costules and veins above glabrous, or with very thin short hairs 
mostly less than 0.2 mm. long; lamina above eglandular; a 
few very narrow scales 1-3 mm. long persistent on the rachis and 

sometimes on the costae below; sori submarginal on the veins 

6. T. ovata var. Lindheimeri. 

6. Costae, costules and often veins above with at least a few rather stout hairs 

mostly greater than 0.3 mm. long; lamina above often with a few 
minute glands; scales absent on the rachis and costae below; sori 
medial to submarginal on the veins (7) 

7(6). One or two pairs of pinnae below somewhat reduced; rhizome short- 
creeping, sometimes appearing suberect; venation variable (even on 
the same frond), from anastomosing with a short excurrent vein 
to connivent at the sinus; lamina above often somewhat hairy; 
veins above always with stout hairs many of which are greater 
than 0.4 mm. long 5. T. quadrangularis var. versicolor. 

7. Lowermost pinnae usually not reduced; rhizome short-creeping to frequently 

long-creeping; veins connivent at the sinus or the distal one of each 
pair meeting the margin slightly above the sinus; lamina above 
glabrous or sparsely hairy; veins above with or without long stout 
hairs 7. T. normalis. 

1. Thelypteris Torresiana (Gaudich.) Alston. Fig. 18. 

Fronds clustered on a stout rhizome, to 2 dm. tall or more; rhizome scales 
linear-lanceolate, acuminate-attenuate, castaneous. long-ciliate, to about 8 mm. 
long; stipes slender to stoutish, stramineous, to 6 dm. long, scaly at base, glabrous 
to sparingly setose; blades deltoid-ovate to triangular-lanceolate, acuminate, bi- 
pinnate-pinnatifid, membranous, setaceous with silvery-white hairs, to 9 dm. long 
and 4 dm. wide; pinnae triangular-lanceolate to narrowly elliptic, acuminate, 
pinnate; pinnules sessile, lanceolate, acute to acuminate, deeply pinnatifid, con- 
fluent at apex, to about 5 cm. long and 1.5 cm. wide; ultimate segments rounded, 
coarsely toothed, about 2 mm. wide; sori solitary at the anterior margin of a 
tooth, 1 to 6 per segment; indusia obsolete, early fugacious. 

Along streams in pinelands, in swamps, marshes and on moist wooded banks, 
in e. Tex. (Newton and Hardin cos.); nat. of Asia and adj. I., escaped from cult, 
and more or less established in cen. peninsula Fla., Ala. to Tex. and trop. Am. 

2. Thelypteris hexagonoptera (Michx.) Weath. Broad beech fern. Fig. 19. 
Fronds distant, erect, arising at 5-15 mm. intervals on a slender creeping 

rhizome, to about 8 dm. tall; rhizome scales light-brown, ovate-lanceolate to linear- 
lanceolate, often long-ciliolate, 3-5 mm. long; stipes weak, slender, stramineous 
or greenish, 2—4.5 dm. long; blades broadly triangular, acute to acuminate, bi- 
pinnatifid, 15-38 cm. long, about as broad as long or broader, slightly pubes- 
cent and frequently glandular on lower surface; rachis irregularly winged through- 
out; primary segments elliptic-lanceolate, acuminate, tapering at both ends, 
pinnatifid, with the lower usually larger pair of segments directed downward and 
away from the rachis at a different angle from the upper segments; ultimate seg- 
ments obliquely oblong, obtuse, subentire to deeply crenate or sometimes nearly 
pinnatifid; sori naked, mostly near the margin. 

On sandy-loamy wooded slopes and in ravines along streams, in open rocky 
thickets, and on the edge of low swampy woods and bogs, rare in e. Okla. and in 
the e. Tex. Timber Belt; from Fla. to e. Tex. and Okla.. n. to Que. and Minn. 

3. Thelypteris palustris Schott var. Haleana Fern. Southern marsh fern. Figs. 

19 and 20. 
Fronds erect from a slender widely creeping rhizome, to 12 dm. tall; rhizomes 
blackish; stipes slender, glabrous or nearly so, stramineous above, purplish toward 
base, about as long as the blade; blades lanceolate to elliptic-lanceolate, short- 

72 




Fig. 20: Thelypteris paliistris: a, upper part of frond, X 1/2; b, rootstock, X 1/2; c, 
pinnae showing one fertile pinnule, X 5; d, sporangia before spores are released, X 
10; e, sporangia after rupturing and releasing spores, X 10, (V.F.). 



acuminate, pinnate-pinnatifid to rarely bipinnate, slightly pubescent (especially 
the rachises), 9-20 cm. wide, membranous to herbaceous; pinnae numerous, linear- 
lanceolate to lanceolate, somewhat acuminate, sessile or nearly so, deeply pinnati- 
fid to rarely pinnate, to 3 cm. wide, the midrib beneath mostly with broad brown 
or tawny scales at the base of the ultimate segments; pinnules or ultimate segments 
mostly linear-oblong, numerous and closely set, entire or with minutely undulate 
margins, obtuse or appearing to be acute because of the revolute margins, to 1.5 
cm. long, with all the veins (including those of the fertile segments) commonly 
once- or twice-forked; sori medial, numerous, sometimes confluent; indusia small, 
glabrous. 

In open sandy bogs, swamps and meadows, or in open low woodlands, seepage 
about lakes and ponds, and along streams, rare in several cos. in the e. Tex. 
Timber Belt and in Jefferson Co. in the Coastal Prairies and Waller and Colorado 
cos. in the Post Oak Prairies; from Fla. to e. Tex., n. to (?) Pa. 

4. Thelypteris dentata (Forsk.) E. St. John. Downy shield fern. Fig. 18. 

Fronds clustered, erect-ascending from a thick rhizome, to 12 dm. tall; stipe 
and rachis purplish; blades ovate-oblong to lanceolate, to 8 dm. long and 28 cm. 
wide; pinnate-pinnatifid, with usually more than 2 pair of greatly reduced pinnae 
at the base, costae below with predominantly short hairs which are uniform in 
length (less than 0.2 mm. and often less than 0.1 mm. long); excurrent veins 
mostly greater than 2 mm. long. Dryopteris dentata (Forsk.) C. Chr. 

On rocky wooded slopes, on hummocks in swamps, and along wooded streams 
at low elev., rare in the Tex. Timber Belt; from Fla. to Tex., in part escaped 
from cult.; also from Mex. to Arg., the W.I., Asia and Afr. 

5. Thelypteris quadrangularis (Fee) Schelpe var. versicolor (R. St. John) A. R. 

Smith. 

Fronds erect, arching, mostly 3-10 dm. tall; rhizomes short-creeping to suberect, 
obscured by the persistent leaf bases; stipes 1.5-5 mm. in diameter, pubescent, 
stramineous above, sometimes darkened at the base, nearly as long as the blades, 
with lanceolate shining dark-brown to castaneous pubescent scales at the base; 
blades elliptic-lanceolate, usually with 1 or 2 pair(s) of somewhat reduced 
pinnae below, occasionally the pinnae very little reduced below, auricled or not, 
1-3 dm. wide, herbaceous; pinnae numerous, linear-lanceolate, sessile, pinnatifid 
two thirds to four fifths of their width, to 2 cm. wide; pinnules linear-oblong, 
somewhat oblique, rounded at the apex, entire; the veins simple, mostly 6 to 9 
pairs per segment, the basal pair from adjacent segments united below the sinus 
with an excurrent veinlet less than 1 mm. long to the sinus or the lower pair of 
veins not uniting at all but approaching each other below the sinus and turning 
abruptly toward the sinus; costae, costules, veins and leaf tissue pubescent above 
and below, the hairs often stout and to 0.8 mm. long; stipitate yellow glands 
often present on both surfaces of the blade; sori medial, numerous or sometimes 
confined to the basal pair of veins, discrete; indusia persistent, pubescent; sporan- 
gial stalks with minute glands. T. versicolor R. St. John. 

On the edge of sandy creeks, boggy or swampy areas and wooded slopes in e. 
Tex.; S.C. to e. Tex.; also Cuba; other vars. in Latin Am. and Afr. 

6. Thelypteris ovata R. St. John var. Lindheimeri (C.Chr.) A. R. Smith 

Fronds erect, arching, mostly 5-14 dm. tall; rhizomes widely creeping, brownish, 
3-6 mm. in diameter; stipes 2-6 mm. in diameter, arising from the rhizome in a 
more or less bilinear series 1-4 cm. apart, glabrous or nearly so, stramineous 
above, darkened at the base, about as long as the blades, paleate at the base, the 
light-brown scales narrowly lanceolate and short-ciliate at the margin; blades 
deltoid-lanceolate, mostly 30-75 cm. long, 15-50 cm. wide, pinnate-pinnatifid, 

74 



tapering evenly toward the pinnatifid apex, chartaceous; rachis sparsely to densely 
pubescent, nearly always with a few persistent narrowly lanceolate light-brown 
scales; pinnae numerous, linear-lanceolate, sessile, deeply pinnatifid three fifths 
to usually more than four fifths of their width, 8-20 mm. wide, the veins and leaf 
tissue glabrous above or sometimes with minute hairs about 0.1 mm. long on the 
leaf tissue above, the costae above and below with longer hairs to 0.5 mm. long; 
costae below usually with a few attenuate scales to 1 mm. long; pinnules linear- 
oblong, often strongly oblique, subfalcate, the margin entire, rounded or usually 
appearing acute because of the revolute margin, the basal segments of the medial 
pinnae frequently narrower and slightly longer than more distal pinnules; veins 
simple, 6-13 pairs per segment, the basal pair meeting the margin at or slightly 
above the sinus; sori supramedial to submarginal, numerous, discrete; indusia 
persistent, pubescent, often glandular; sporangial stalks eglandular. Dryopteris 
normalis var. Lindheimeri C. Chr. 

On wet bluffs and ledges in canyons, especially at the base of dripping limestone 
bluffs, about springs and along water courses, on the Edwards Plateau in cen. Tex. 
s, to n. Ver. and Pue. 

7. Thelypteris nomialis (C. Chr.) Moxley. Fig. 18. 

Fronds erect, arching, mostly 5-15 dm. tall; rhizomes creeping, brownish, 
4-8 mm. in diameter; stipes usually 3-6 mm. in diameter, arising from the 
rhizome at 1-3 cm. intervals in a more or less bilinear series (infrequently the 
stipes clustered), stramineous above, darkened at the base, about as long as the 
blade, glabrous to moderately hairy, paleate at the base; rhizome scales castaneous, 
shining, lanceolate, more or less pubescent; blades lanceolate (the lowest pair of 
pinnae the longest or only slightly shorter than the next pair of pinnae), mostly 
3-7 dm. long, 16-30 cm. wide, pinnate-pinnatifid, herbaceous to chartaceous, the 
rachis pubescent and often stipitate-glandular, rarely with a few persistent scales; 
pinnae numerous, sessile, linear-lanceolate, to 2 cm. wide, pinnatifid three fifths 
to three fourths of their width, the costae, costules and sometimes the veins 
above more or less pubescent with hairs mos'ly 0.2-0.5 mm. long, the tissue 
between the veins above glabrous; pinnules numerous, linear-oblong, somewhat 
oblique, rounded at the tip or appearing acute because of the revolute margins, 
entire except for the basal pinnae segments of the lower pinnae which may be 
slightly enlarged with a crenate margin (auricles present); veins simple (except 
those of the auricles which may be once-forked), 6 to 11 pairs per segment, 
connivent at the sinus or the distal one of each pair meeting the margin slightly 
above the sinus; sori medial, numerous, usually discrete; indusia large, persistent, 
moderately to densely hairy; sporangial stalks with minute stipitate glands. T. 
Kunthii of auth., Dryopteris normalis C. Chr. 

On the edge of sandy creeks, in swamps, low wet woods and slopes in e. Tex.; 
W. I. and Mex. to n. S.A. 

7. Dryopteris Adans. 

Rhizomes stout, erect or short-creeping; scales fibrous, glabrous, entire to 
toothed, not ciliate; fronds and pinnae sometimes more or less dimorphic; blades 
pinnate-pinnatifid to tripinnate; stipes stout, stramineous, shorter than the blades, 
with 3 to 7 free bundles; ultimate segments mostly toothed, often subspinulose, 
glabrous, not ciliate, occasionally capitate-glandular, sparingly to densely scaly, 
the minor axes decurrent on the major ones to form the sides of the dorsal grooves; 
veins free, simple or mostly forked, ending short of the margin in elongate hyda- 
thodes; sori dorsal on the veins, inframedial to submarginal; indusium reniform, 
large, persistent, glabrous, sometimes glandular on margin or back. 

A large world-wide genus of about 150 species that are found mainly in tropical 
and subtropical regions of both hemispheres. 

75 




Fig. 21: 1 and 2, Dryopteris cristata: 1, frond and rhizome, X %; 2, enlarged 
pinna, X 3. 3 and 4, Dryopteris ludoviciana: 3, pinna, X %; 4, detail of pinnules, 
X 3. (From Correll in Lundell's Flora of Texas, Vol. 1, PI. 33). 



1. Fertile segments not contracted; fertile fronds with most or all of the pinnae 

fertile, erect, 2 to 3 times as long as the spreading sterile fronds 

1. D. cristata. 

1. Fertile segments sharply contracted to about one half the width of the sterile 
segments; fertile fronds with fertile pinnae only in upper half, 2 
times or less the length of the sterile fronds 2. D. ludoviciana. 

1. Dryopteris cristata (L.) Gray. Crested shield fern. Fig. 21. 

Fronds inconspicuously dimorphic, clustered on a thick rhizome, glabrous on 
upper surface, sparsely scaly on lower surface, to 12 dm. tall; sterile fronds broad 
and spreading, usually evergreen; fertile fronds narrow and erect; blades (of both 
types of fronds) subcoriaceous, linear-oblong to lanceolate or narrowly elliptic- 
lanceolate, to 8 dm. long and 15 cm. wide, pinnate-pinnatifid to nearly bipinnate; 
ultimate segments mostly toothed, often subspinulose, glabrous, not ciliate, some- 
times capitate-glandular, sparingly or densely scaly; veins free, simple or mostly 
forked, ending short of the margin in elongate hydathodes; sori dorsal on the 
veins. 

In marshes, bogs, swamps, thickets and meadows, and on springy wooded 
slopes, at low elevations, if extant in our region, only in the n.e. corner of the 
Tex. Timber Belt (Bowie Co., "margin of sandy bog near Texarkana," October 
27, 1925, E. J. Palmer 29404, p. p.); from Nfld. to Ida., s. to e. Va., N.C., s.e. 
Ark., n.-cen. La. and n.e. Tex. 

6. Dryopteris ludoviciana (Kunze) Small. Fig. 21. 

Rhizomes horizontal, with cinnamon-colored scales; fronds arising in a short 
row behind a cluster of apical buds; blades oblong, 5-10 dm. long, 1.5-3 dm. 
wide, pinnate-pinnatifid to almost bipinnate; pinnae lanceolate, about 4 times as 
long as wide, the basal pinnae triangular and one half to less as long as longest 
pinnae, their ultimate segments more or less dimorphic and serrate; fertile pinnae 
with more widely spaced segments that are constricted to about one half the width 
of the sterile segments; sori inframedial; indusia nonglandular. 

In swamps, in seepage at base of bluffs, low wet woods and on stream banks, in 
s.e. Tex (Hardin and Tyler Cos.); from e. N.C. s. to Fla. and w. to s.e. Tex. 

Fam. 11. Parkeriaceae Hook. Floating Fern Family 

Aquatic or semiaquatic plants with roots on the stipes; stems creeping, sparsely 
scaly, reduced; fronds alternate, successive, viviparous, fleshy-herbaceous, di- 
morphic, reticulate-veined, floating or emergent; sporophylls erect, taller and 
more finely divided than the sterile fronds, the linear ultimate segments with the 
margins evenly and narrowly revolute; sporangia solitary. 

Only one genus. 

1. Ceratopteris Brongn. 

Characteristics of the family. Three species, mostly in the tropics and sub- 
tropics of both hemispheres; edible aquatic plants. 

1. Ceratopteris thalictroides (L.) Brongn. Fig. 22. 

Fronds erect, strict, to 75 cm. long, usually much smaller; stipes 4—27 cm. long; 
lamina of sterile frond narrowly deltoid to oblong, to 28 cm. long and 13 cm. 
wide, 1- or 2-pinnate or -pinnatifid with the pinnae ovate-lanceolate; segments 
Hnear-lanceolate to oblong, acute, to 25 mm. long and 5 mm. wide; sporophylls 
taller than the sterile fronds, the oblong lamina 2- to 5-pinnately divided with the 
pinnae and smaller divisions distant; ultimate segments flagelliform, 1-5 cm. long, 
the margins narrowly revolute to cover 1 or 2 rows of areolae and sporangia. 

77 




Fig. 22: Ceratopteris thalictroides: a, habit, X Vs; b, enlargement of part of fertile 
frond; c, enlargement of viviparous pinna; d, enlargement of viviparous pinnule. 
(V.F.). 



Well established in spring-fed back-waters of the San Marcos River in Hays 
Co., Tex. where it was originally introd. (probably about 1960); nat. apparently 
to both hemispheres; also in s. Fla. 

It is quite possible that the other two species in this genus, C. pteridoides 
(Hook.) Hieron. and C deltoidea Benedict, may be introduced in Texas rivers. 
In contrast to C. thalictroides, they both have broadly deltoid fronds. The sterile 
fronds of C. pteridoides are usually simple with broad basal lobes and short, often 
swollen, stipes that are widest at base of blade and tapered downward, while the 
sterile fronds of C. deltoidea are pinnately divided, with long, slender stipes. 



Division II. Spermatophyta 



Seed-Bearing or Flowering Plants 



Plants producing seeds that contain the young plants in a dormant condition 
until germination. Sporophylls arranged in groups (flowers) of definite or in- 
definite numbers, heterosporous, those bearing microsporangia (anther sacs) 
termed stamens, those producing macrosporangia (ovules) carpels. The game- 
tophytes very much reduced, the female being confined within the macrosporangia 
where its egg-cell is fertilized by the spermatozoid of the male gametophyte (pollen 
tube), the sporophyte thus beginning its development while still attached to the 
sporophyte of the preceding generation. Eventually detached in an embryonic 
stage, together with the enclosing tissues, as a seed. 

The seed-bearing plants form the most numerous plant group in existence, more 
than 200,000 species being known. The seed-habit, now restricted to the Spermato- 
phyta, is also known to have occurred in ancient fernlike plants. This category 
is now considered essentially one of convenience rather than distinction because 
of the apparent diverse ancestry of its component members. 

Class 1. Gymnospermae 

Plants monoecious or dioecious, more or less resinous trees or shrubs; ovules 
and seeds not enclosed in an ovary, typically borne on scales that are arranged 
in a cone or strobilus, or sometimes terminal on naked or bracteate stalks, micro- 
sporangia mostly embedded in microphylls that are arranged in a cone or strobilus; 
male and female cones distinct, dissimilar. 

The Gymnosperms comprise an ancient remnant of about 700 species of trees 
and shrubs that are considered to have been most abundant in the Mesozoic. The 
group contains such relicts as the Cycads, the Ginkgo tree, Metasequoia and 
Araucarias. 

Fam. 12. Taxodiaceae Warming Taxodium Family 

Deciduous or essentially evergreen trees with light-brown furrowed and scaly 
bark and upright or spreading branches; branchlets of two kinds, those near the 

79 




Fig. 23: 1 and 2, Taxodium distichum: 1, leafy branchlet with mature cones, 
X %; 2, twig, X 1. 3, Taxodium mucronalum: 3, spikes of staminate cones, X %. 



apex of the shoot persistent and with axillary buds, those on the lower part of 
the shoot without axillary buds and deciduous; winter-buds globose, scaly; leaves 
alternate, subulate or flat and linear with stomatic bands below, those of the 
deciduous branchlets usually spreading in two ranks, those of the persistent 
branchlets spreading radially; staminate flowers ovoid, consisting of 6 to 8 stamens 
and forming terminal drooping panicles; pistillate flowers scattered near the ends 
of the branches of the preceding year, subglobose, consisting of 2-ovuled scales; 
fruit a short-stalked globose or ovoid cone that ripens the first year, consisting 
of many thick coriaceous peltate scales that are dilated from a slender siine into 
an irregularly 4-sided often mucronate disk; each fertile scale with 2 unequally 3- 
angled seeds with 3 thick wings. 

About 16 species in 10 genera in both hemispheres. 

1. Taxodium Rich. Bald Cypress 

Trees with light-green deciduous leaves and slender leafy branchlets of the 
season that are deciduous in autumn, monoecious, often with erect columnar 
"knees" produced from the roots in areas of frequent flooding; flowers unisexual, 
the two kinds on the same branches; staminate flowers in panicles of short or 
slender spikes, with few stamens; filaments scalelike, peltate, bearing 2 to 5 anther 
cells; pistillate aments ovoid, in small clusters, scaly, with a pair of ovules at the 
base of each scale; cone closed, globular, composed of thick and angular some- 
what peltate scales that bear two 3-angled seeds at their bases. 

Three species in southern United States and Mexico. Important timber trees 
that are commonly grown for their ornamental qualities. 

1. Distribution in Oklahoma and Texas north of the Rio Grande Valley; decidu- 
ous; branches of staminate flowers short and crowded, the flowers 
commonly in short compact secondary branches 1. T. distichum. 

1. Distribution in Texas confined to the Rio Grande Valley; essentially evergreen; 
branches of staminate flowers long and slender, open, composed of 

single flowers or tight clusters of several flowers 

2. T. mucronatum. 

1. Taxodium distichum (L.) Rich. Bald cypress, southern cypress. Fig. 23. 

Tree occasionally to 50 m. tall, with a tapering trunk strongly buttressed at 
the swollen base, pyramidal when young, in old age usually spreading to form a 
broad rounded head; bark reddish-brown or gray, with long fibrous or scaly 
ridges; young branchlets green, becoming brown the first winter; the 2-ranked 
feathery leaves linear to linear-lanceolate, flat, apiculate, 1-1.5 cm. long, soft- 
bright-green to yellowish-green or whitish below, turning dull-orange-brown be- 
fore falling; panicle of staminate flowers 10-12 cm. long; cone globose or obovoid, 
about 25 mm. across; disk of hard scales, rugose, usually without a mucro; seeds 
heavy, angular, about 1 cm. long. 

In swamps and along rivers and streams in Okla. (McCurtain Co.) and in e. 
Tex., w. from Brazoria Co. to Real and Uvalde cos. on the Edwards Plateau in 
cen. Tex.; from Del. to Fla., w. to 111., Mo., Okla. and Tex. 

Especially in wet and frequently inundated areas the roots produce woody 
cylindrical projections to 2 m. tall and 3 dm. in diameter that are called "cypress- 
knees." An important timber tree that is sometimes grown for its ornamental 
value. Individuals of this species exhibit some remarkable genetic differences. For 
example, near Saratoga (Hardin Co., Tex.) two trees growing side by side have 
the appearance of two entirely different species. One, with open crown, has its 
branches ascending, while the other, with a dense closed crown, has spreading and 
descending branches. 

81 



2. Taxodium mucronatum Ten. Montezuma bald cypress, sabino, ahuehuete, 
ciPRES. Fig. 23. 
Large tree with straight trunk enlarged near the base, to 30 m. high; bark 
brownish-red, relatively smooth to shallowly furrowed, fibrous, more or less 
shredded; leaves linear, 6-12 mm. long, spreading in nearly 2-ranked sprays, these 
and some young branchlets falling with appearance of new growth; staminate 
cones small, ovoid, 1.5-2.5 mm. long, in slender spikes 5-15 cm. long; ovulate 
cones subglobose, 15-25 mm. in diameter; seeds dark-reddish-brown, 4-8 mm. 
long, irregularly angular because of crowding. 

Along the Rio Grande and occasionally along resacas in Cameron and Hidalgo 
cos. in the Rio Grande Valley of Tex.; from s. Tex., s. on the Mex. tableland 
and along the coast of the Gulf of Mex. 

This species is the famous large tree of Santa Maria del Tule, Oaxaca, Mexico, 
which, according to the best authority, has a height of about 39 meters and a 
trunk circumference of 52 meters, with the spread of its branches about 42 
meters. 



Class 2. Angiospermae 

Plants diverse in habit, structure, form, size, habitat and sexualization; ovules 
and seeds borne enclosed in carpels that are at the center of flowers and which 
are interpreted as fertile fronds with megasporangia on the upper surfaces, these 
fronds are loosely folded along a median zone in such a way that the margins 
meet to form a more or less firmly sealed ventral (adaxial) suture; carpels either 
free (constituting a simple pistil) or often several united into a compound pistil; 
ovule-bearing portion of the pistil (the ovary) maturing into the fruit; gameto- 
phytic stage of the plant of very short duration (a matter of only a few hours) 
as compared to the gymnospermous counterparts, and the male gamete reaching 
the female gamete (in the ovule) by means of a tube that penetrates the tissues 
of the carpel; fertilization consisting of a double process: not only does the 
sperm-nucleus fertilize the egg-nucleus to form a diploid zygote which develops 
into the embryonic sporophyte in the seed, but another simultaneous fertilization 
in the same female gametophyte results in a triploid or higher polyploid nucleus 
which in many members of the class produces a nutritive tissue called endosperm 
closely associated with the embryonic sporophyte. 

A stupendous array of about 200,000 species including all of the important 
sources of food and fiber, and including all the plants which the man in the street 
calls flowers. 



Fig. 24: Typha lati folia: a, pistillate spike, X %; b, single compound pedicel of 
pistillate spike, X 20; c, upper part of plant, showing distichously arranged leaves 
and young contiguous spike with staminate flowers (above) and pistillate flowers 
(below), X ':,; d, somewhat older spike, X %; e, variation in spike size X %; f, 
4-celIed pollen grains; g, group of compound pedicels of pistillate spike, X 4; h, young 
pistillate flowers, the pedicel not yet elongated, and fascicled hairlike bracts, X 12; 
i and j, stamens on branched filaments, X 6; k, staminate bracts, commonly white 
or brown-tipped. X 6; 1, oblanceolate fleshy stigma, X 12; m, sterile pistillate flower 
with ellipsoid aborted ovary tipped by rudimentary style, the surrounding hairs, like 
those of fertile flower, originating at base, X 4; n. sterile ovary, light-brown, X 12; 
o, pistillate flower with mature functional ovary, X 4. (From Mason, Fig. 8). 

82 



Subclass 1. Monocotyledoneae 

Cotyledons usually solitary; embryonic radicle usually developing only to a 
very limited extent, most of the roots being adventitious on the lower part of 
the stem, resulting in a so-called fibrous root system; vascular strands of the 
stem usually not in any cylindrical pattern, the stem-transection revealing a num- 
ber of scattered strands; vascular strands (nerves, veins) of the leaves usually not 
forming a network but parallel for most of their length; sepals, petals, stamens and 
carpels usually in multiples of three, but many exceptions. 

Plants with long, narrow leaves such as grasses, sedges and lilies are charac- 
teristic of this subclass; but such bizarre plants as palms, yuccas and century 
plants also belong here. About 50,000 species, roughly a fourth of all angiosperms, 
fall into this group. 

Fam. 13. Typhaceae Juss. Cat-tail Family 

Aquatic or paludal monoecious perennial herbs with a creeping rhizome and 
distichously arranged erect leaves; leaves sessile, linear, nerved, glabrous, sheath- 
ing the base of the simple jointless stems; flowers unisexual, in a long dense 
cylindrical spike terminating the stem, without proper floral envelopes; staminate 
flowers forming the upper portion of the spike, consisting of stamens inserted 
directly on the axis and intermixed with long hairs or slender bracts; pistillate 
flowers forming the lower portion of the spike, consisting of stipitate 1 -celled 
fertile or abortive ovaries with their stipes provided with ascending or spreading 
slenderly clavellate bristles that form the copious down of the fruit; ovary 1 -celled 
and I-ovuled, with usually persistent linear style and elongated 1 -sided linear or 
linear-lanceolate stigma; fruit a long-stalked minute nutlet; seed suspended, 
anatropous. 

A solitary genus. 

1. Typha L. Cat-tail 

Characters of the family. About 15 species of worldwide distribution. 

The stalks, thick rootstocks and roots are important foods for muskrats and 
beaver. The rootstocks and, in some instances, the minute seeds are known to 
be eaten by geese and teal. The thick shelter and nesting cover afforded and the 
insects supported by these plants attract marsh birds, wildfowl and song birds. 
The plants also provide shelter for young fish and a spawning ground for sunfish. 
On the whole, however, these plants are considered as undesirable because they 
often displace more desirable species and, uncontrolled, they can rapidly cover 



Fig. 25: Typha angustifoUa: a, swollen aborted ovary with rudimentary style, 
X 20; b, sterile long-stipitate flower with terminal aborted ovary, the hairs on stipe 
in whorls, terminating in club-shaped or ligulate tips, X 8; c. young spike, showing 
area of separation between staminate spikes (above) and pistillate spikes (below), 
X %; d, single compound pedicel of pistillate spike, X 40; e, group of compound 
pedicels, appearing smooth, X 8; f, cluster of spatulate truncate bracts, with transi- 
tional forms resembling abortive ovaries, occurring frequently among flowers, X 8; 
g and h, upper part of plant, showing distichous leaf arrangement and young flower- 
ing spikes, X %; i, cluster of young anthers surrounded by bracts, filament not yet 
elongated, X 6; j-1, mature stamens, 2 to 6 anthers in a cluster sessile on a single 
filament, X 6; m-o, staminate bracts — linear, simple, and forked types, X 6; p, 1 -celled 
pollen grains; q, group of young fertile and sterile pistillate flowers, the pedicels not 
yet elongate, X 12; r, swollen tip of pistillate bract, X 40; s, pistillate bracts, X 8; t, 
auricle of sheath, X %; u and v, mature pistillate flowers with functional ovaries, 
long styles and linear stigmas, the pedicels of varying length and surrounded by basal 
hairs, X 8. (From Mason, Fig. 9). 

85 



over and desiccate a water area, especially if the area is small and shallow. It 
has been found that mowing cat-tails after their heads are formed but still im- 
mature, followed by a second mowing a few weeks later, will control these plants 
to a considerable degree. 

1. Staminate and pistillate portions of spike usually contiguous; stigmas ligulate 
to lanceolate; sterile ovary ellipsoid, tipped at the rounded apex by 
a rudimentary style; leaves flat on back 1. T. latifolia. 

1. Staminate and pistillate portions of spike usually separated by an interval; 

stigmas linear to filiform; sterile ovary not ellipsoid; leaves com- 
monly convex on back (2) 

2(1). Leaves 5-8 mm. wide, dark-green; sterile ovary cuneate, with a rudimen- 
tary style on the truncate-flattened apex 2. T. angustifolia. 

2. Leaves 7-15 mm. wide, light-yellowish-green; sterile ovary obovoid, the 

rounded apex tipped by a short rudimentary style 

3. T. domingensis. 

1. Typha latifolia L. Common cat-tail, tule espadilla. Fig. 24. 

Plant coarse and stout, to about 3 m. tall; pith of the stem base white; leaves 
essentially flat, sheathing, pale- or grayish-green, 6-23 mm. wide, often exceeding 
the stem; sheaths cylindrical but open to base, the scarious upper margin tapering 
to blade, rarely truncate or slightly auricled; the staminate and dark-brown pistil- 
late parts of the spike usually contiguous, the staminate portion to 12 cm. long, 
the pistillate portion to 2 dm. long, when in fruit 15-35 mm. thick, its surface 
(when magnified) appearing minutely pebbled with crowded persistent stigmas 
and scarcely bristly; pistillate flowers without bractlets among the bristles; stigma 
ovate-lanceolate, fleshy, persistent; pollen grains in fours; denuded axis of old 
spike retaining slender pedicels that are 1-2 mm. long. 

In marshes or shallow water and along streams throughout most of our area, 
Mar.-May; from Nfld. to Alas., through most of the U. S. into Mex. 

2. Typha angustifolia L. Narrow-leaved cat-tail. Fig. 25. 

Plant slender, to about 15 dm. tall, the stem pith white; leaves mostly less 
than 10, somewhat convex on back, dark-green, 3-7 mm. wide; sheaths appearing 
cylindrical below but actually open to base, usually conspicuously auriculate 
above, rarely with some sheaths tapering to the blade, the auricles scarious- 
margined; pistillate and staminate parts of spike usually separated by a short 
interval; pistillate portion of spike reddish-brown, in fruit to 15 cm. long and 
15 mm. thick, its surface minutely bristly with persistent linear stigmas; staminate 
portion of spike to 2 dm. long; pollen grains simple; pistillate flowers with a 
linear fleshy stigma and usually with a hairlike bractlet with dilated blunt tips 
among the bristles; the denuded old axis covered with stout blunt compound 
papiHate pedicels that are 0.5-0.7 mm. long. 

In coastal and inland marshes in Okla. and mainly in s. Tex.; from N.S. and 
s. Me. to s. Que. and Ont., s. to S. C, W. Va., Ky., Mo., Neb. and Tex.; also 
Calif, and Euras. 



Fig. 26: Typha domingensis: a, fertile pistillate flower, showing mature ovary and 
the surrounding hairs originating at base of stipe, bract attached, X 8; b, sterile pis- 
tillate flower terminating in a swollen aborted ovary, hairs surrounding stipe in whorls, 
X 8; c, aborted obovoid ovary tipped by rudimentary style, x 20; d-f, typical bracts, 
showing variations in the swollen tips, X 12; g and h, bracts of staminate flowers, 
slender, simple or laciniate, with dark-brown shiny tips, X 12; i, 1 -celled pollen grains, 
grains occasionally in pairs; j and k, compound pedicels of pistillate spike, j, X 9, 
k, X 40; 1 and m, spike, showing area of separation between the staminate part 
(above) and the pistillate part (below), X %; n, pistillate spike, X %. (From Mason, 
Fig. 7). 

87 




Fig. 27: Sparganiiim eurycarpum: a and b, 1 -seeded and 2-seeded fruits (cross 
sections), X \Vi\ c, mature fruit, X lil>; d, paired staminate flowers, usually with I 
broad perianth scale and several long-clawed scales expanding into a spatulate apex, 
the anthers elliptic-clavate, X 6; e, staminate inflorescence showing globose heads, 
X %; f, young sessile pistillate flowers, showing the perianth scales with spatulate 
apex, the scales broader than those of the staminate flowers, X 4; g, young fruiting 
bur, showing (he long 2-lobed style branches, X %; h, habit of plant, X !«; i, mature 
fruiting head, the styles broken ofl", X %. (From Mason, Fig. 10). 



3. Typha domingensis Pers. TuLE. Fig. 26. 

Plant slender, to about 3 m. tall, the stem pith white; leaves 6 to 10, usually 
flat, yellowish-green, firm or coriaceous, 7-15 mm. wide, usually shorter than the 
inflorescence; sheaths tapering at throat to the blade, scarious-margined above; 
staminate portion of spike 2-4 dm. long, more or less separated (sometimes by 
as much as 6 cm.) from the whitish-brown pistillate portion; surface of spike 
similar to that of T. angustifolia; stigmas linear, interspersed with many apiculate- 
bladed bractlets, soon deciduous; compound pedicels 0.5-0.8 mm. long. T. 
truxillensis H.B.K. 

In brackish or fresh marshes and pools throughout most of our area, Apr. -May; 
from Fla. to Tex. and s. Calif., n. along the coast to Del. and e. Md. and inland 
to Kan., Ut., Nev. and n. Calif.; also trop. Am. 

Fam. 14. Sparganiaceae Rudolphi Bur-reed Family 

Perennial marsh or aquatic monoecious plants with horizontal rootstocks and 
alternate sessile 2-ranked linear leaves on an erect simple or branched stem; 
flowers in distant somewhat regularly disposed globular sessile or pedunculate 
heads on the upper part of the stem or its branches; upper heads bearing sessile 
staminate naked flowers and minute scales irregularly interposed; lower heads 
composed of numerous sessile or shortly pedicelled pistillate flowers with a calyx- 
like perianth of 3 to 6 linear to spatulate or obovate-flabellate scales; bracts 
caducous or the lower ones persisting and leaflike; ovary 1- to 2-ceiled; achenes 
suborbicular to obovoid to fusiform, 1- or 2-seeded, 

A monotypic family. 

1. Sparganium L. Bur-reed 

Characters of the family. Pistillate heads becoming burlike from the divergent 
beaks but the achenes at maturity falling separately in summer and autumn. 

About 20 species in the temperate and cold regions of both hemispheres. 

Waterfowl and marsh birds are known to eat the achenes, and muskrats eat the 
basal parts or even the entire plant of all our species. They are also eaten by 
deer. Their primary value, however, is as cover plants that attract marsh birds 
and waterfowl. 

1. Mature achenes sessile, typically broadly cuneiform to obpyramidal, usually 
more than 4 mm. thick across top, truncate to broadly rounded at 
apex with the stout beak produced rather abruptly; stigmas usually 

2 but (in our region) 1 not uncommon; inflorescence usually 
branched 1. S. eurycarpum. 

1. Mature achenes more or less stipitate, typically fusiform or rarely somewhat 

fusiform-obovoid, somewhat tapered at both ends, usually less than 

3 mm. thick, gradually tapered to the rather slender beak, occa- 
sionally somewhat constricted at about the middle; stigma always 1; 
inflorescence simple or branched (2) 

2(1). Staminate head usually single; fruiting heads to 1.5 cm. in diameter; beak 

of achene usually about 1 mm. long, rarely to 1.5 mm 

2. S. minimum. 

2. Staminate heads usually 2 or more; fruiting heads usually 2 cm. or more in 

diameter, rarely less; beak of achene 2 mm. long or more (3) 

3(2). Heads (or at least one of them) supra-axillary; distribution New Mexico 
and Arizona (4) 

3. Heads or branches of inflorescence all axillary; distribution Oklahoma and 

Texas (5) 

89 




Fig. 28: a-c. Sparf^anium minimum: a. habit, X U; b, enlargement showing separate 
staminate and pistillate heads, X 2V2; c, fruit, X 5. d-i, Trif^lochin paluslrc: d, habit, 
X 1/2; e. ligule, X 5; f, flower, X 5; g, fruit, X 5; h, fruit showing 3 carpels with 
2 carpels in section, X 5; i, cross section of fruit showing 3 carpels, X 5. (V.F.). 



4(3). Stems and leaves mostly partially emersed; leaves typically more than 5 
mm. wide, sometimes scarious-margined near the base; fruiting 
heads usually 2 cm. thick or more; stigma about 1.5 mm. long; 

achene beak (including the stigma) well over 2 mm. long 

3. S. emersum. 

4. Stems and leaves typically submersed or floating; leaves mostly less than 5 

mm. wide, not scarious-margined; fruiting heads usually less than 
2 cm. thick; stigma scarcely 1 mm. long; achene beak (including 
stigma) about 2 mm. long 4. 5. angustifolium. 

5(3). Leaves soft and flaccid; inflorescence simple or the branches strict and 
bearing 1 to 6 staminate heads; bracts mostly spreading; fruiting 
heads 1.5-2.5 cm. thick; stigma 1-1.5 mm. long; achenes usually 
somewhat stipitate, the body 3-5 mm. long, not noticeably con- 
stricted; receptacle scarcely alveolate 5. S. americanum. 

5. Leaves firm and rigid; inflorescense commonly branched, the branches zig-zag 

and bearing 3 or more staminate heads and as many as 2 pistillate 
heads; bracts ascending; fruiting heads 2.5-3.5 cm. thick; stigma 
L5-3 mm. long; achenes subsessile, the body 5.5-7 mm. long, 
usually strongly constricted at middle; receptacle fimbrillate- 
alveolate 6. S. androcladum. 

1. Sparganium eurycarpum Engelm. Broadfruited bur-reed. Fig. 27. 

Stem stout, erect, branching, 5-18 dm. tall; leaves 5-10 dm. long, 7-17 mm. 
wide, flat, somewhat keeled below, as long as or slightly shorter than the branched 
inflorescence; pistillate heads 2 to 6 on the main stem or on branches, sessile or 
usually peduncled, 2-2.5 cm. in diameter in fruit; staminate heads 8 to 12; anthers 
1-L5 mm. long, elliptic-clavate; perianth scales long-clawed, expanding into a 
spatulate apex, irregularly shallowly lobed and hyaline-margined at apex, two 
thirds to three fourths as long as the fruits; style branches usually 2 but often 1 
in our area, filiform, about 2 mm. long; achenes sessile, hard and thick at maturity, 
cuneate-obpyramidal, irregularly and obtusely 3- to 5-angled, 6-10 mm. long 
and 4-8 mm. wide at apex, the top truncate to depressed or very shallowly 
rounded, the stout beak 2-3 mm. long. , 

Fresh-water or brackish marshes, meadows, ponds, lakes and streams in Okla. 
(reported from), N.M. (Lincoln and Otero cos.) and Ariz. (Apache and Navajo 
COS.), May-Oct.; Nfld. to B. C, s. to Va., Mo., Okla., N.M., Ariz, and Calif. 

2. Sparganium minimum (Hartm.) Fries. Fig. 28. 

Slender submersed or suberect plants, 1-8 dm. long; leaves flat, 2-8 mm. wide, 
without an evident keel; inflorescence simple, rarely over 6 cm. long; fruiting 
heads 2 to 4, all sessile or the lowest one short-stalked in axils of bracts, 8-15 mm. 
in diameter; staminate head solitary; perianth scales elliptic to cuneate-spatulate, 
one half to two thirds as long as the body of the achene; achene with its ellipsoid 
to obovoid-fusiform somewhat centrally constricted body about 3 mm. long and 
with a short stipe scarcely 1 mm. long, the beak 1-1.5 mm. long. 

Submerged in shallow water of mt. lake in n. Ariz. (Coconino Co.), June-Sept.; 
Lab. to Alas., s. to N.J., Tenn., Ariz, and Calif. 

3. Sparganium emersum Rehm. Fig. 29. 

Stem rather stout but sometimes slender, 3-10 dm. taU; leaves 2-8 dm. long, 
4-8 (-15) mm. wide, slightly keeled to triangular-keeled especiaUy toward the 
somewhat expanded scarious-margined base, usually well-overtopping the usually 
simple inflorescence; pistillate heads 2 to 5, the lowest ones peduncled, the upper 
ones sessile, at least some of them supra-axillary; staminate heads 3 to 8, con- 
gested or confluent; anthers 1-1.5 mm. long, elliptic-clavate; perianth scales 
oblanceolate, arose at broadened apex; stigma linear, about 1.5 mm. long; fruiting 

91 




Fig. 29: Sparfianium emersum var. muUipcdiinculatuin: a. mature fruit, X 4; b, 
mature fruiting head, X ':,; c, young pistillate flowers, stipitate, X 4; d, group of stanii- 
nate flowers with irregular perianth scales, X 6; e, habit, showing the triangular-keeled 
leaves and bracts and the fruiting burs, X %; f, young plant with leaves over-topping 
the staminate inflorescence, X %; g, 1-seeded fruit (cross section), X 4. (From Mason, 
Fig. 12). 



heads 2-3 cm. in diameter; achenes brown or greenish-brown, prominently stipi- 
tate, the fusiform body 4-6 mm. long and often constricted at the middle, the 
beak (including the stigma) 3-5 mm. long. S. simplex of Am. auth., illegit. name. 

Mucky bottoms of shallow ponds, along streams and sloughs, in N.M. (Sando- 
val, San Miguel and Taos cos.) and Ariz. (Coconino Co.), June-Oct.; La. to Alas., 
s. to Pa., N.M., Ariz, and Calif.; Euras. 

The North American plant is referred to var. midtipedunculatum (Morong) 
Reveal [S. multipendimculatum (Morong) Rydb.] with not so strongly keeled 
basal leaves, somewhat V-shaped in cross section, and with mature achenes 
(including the stipe and beak) about 10 mm. long. 

4. Sparganium angustifolium Michx. 

Slender usually submersed aquatic, the leaves and stems floating or below the 
surface, 3-10 dm. long; leaves usually 2-6 mm. wide, often very long, curved on 
the back; inflorescence usually simple but the lower 1 or 2 pistillate heads long- 
stalked and borne in the axil or above the axil of a bract; pistillate heads 2 to 4; 
staminate heads usually 2 to 5, somewhat confluent; perianth scales borne at base 
of the constricted part of the ovary or at base of stipe; stigma scarcely 1 mm. 
long; fruiting heads less than 2 cm. in diameter; achenes sessile or stipitate, often 
both kinds in the same head, the fusiform body 2.5-3 mm. long, the beak (includ- 
ing stigma) about 2 mm. long. 

Usually in shallow or deep water in high montane lakes in n. N.M. (Rio Arriba 
and Colfax cos.) and n. Ariz., June-Oct.; Lab. to Alas., s. to Pa., N.M., Ariz, and 
Calif.; Euras. 

It is quite possible that this concept should be united with S. emersum. Their 
separation, based primarily on size diff^erences of various organs, is most tenuous. 

5. Sparganium americanum Nutt. Fig. 30. 

Plants stout to slender, to 1 m. tall; leaves soft, thin, flat, translucent, loosely 
ascending or occasionally floating, to 2 cm. wide; lower bract similar to leaves, 
spreading-ascending, scarious-margined at base; inflorescence simple or sometimes 
branched, the heads or branches axillary, the primary axis with 1 to 5 pistillate 
heads and 5 to 9 staminate heads, the branches (when present) with 1 to 6 
staminate heads and 1 to 3 (rarely 0) pistillate heads; anthers 0.8-1.2 mm. long; 
stigma linear-oblong to lanceolate, 1-2 mm. long; fruiting heads 1.5-2.5 cm. in 
diameter; achenes dull or but slightly lustrous, the body 2 mm. thick, the beak 
L5-5 mm. long; anthers about 1 mm. long. 

In shallow water in e. Okla. (Delaware and Le Flore cos.) and e. Tex., Apr.- 
June; from Nfld. to Ont., Wise, Minn, and N. D., s. to Fla., Ala., Tex. and Mo. 

See note under S. androcladum. 

6. Sparganium androcladum (Engelm.) Morong. 

Plants stout, to 12 dm. tall; leaves stiffish, strongly ascending, elongate, nearly 
flat but keeled below, 4-15 mm. wide; lower bracts similar to the leaves, slightly 
scarious-margined at base; inflorescence branched or rarely simple, the primary 
axis with 1 to 4 mostly sessile axillary pistillate heads and 4 to 10 staminate heads, 
the 1 to 3 filiform strongly arched geniculate branches with 3 to 8 staminate heads 
and rarely 1 pistillate head; stigma filiform, 2-4 mm. long; fruiting heads 2.5-3.5 
cm. in diameter; achenes lustrous, the body 2.5-3 mm. thick, the beak 4.5-6 mm. 
long; anthers 1-1.5 mm. long; receptacle fimbrillate-alveolate. 

In swamps and shallow water of streams in e. Okla. (Ottawa Co.) and e. Tex., 
Apr.-June; from Que. to Minn., s. to Va., e. Ky., 111., Mo., Okla. and Tex. 

Plants that comprise S. americanum and 5". androcladum, which have the heads 
or branches of their inflorescence all axillary, are restricted in our area to eastern 
Oklahoma and eastern Texas. Voucher specimens of plants that we have examined, 

93 












Fig. 30: Sparganium americanuin: a, habit, X I4; b, cross section of leaf, X 1; 
c, section of staminate head, X 1|,1>; e, pistillate head, about X 1; f, fruits, one with 
and one without perianth scales, X 3; g, mature fruit, X 3. (Courtesy of R. K. 
Godfrey). 



not only from our region but from elsewhere, do not readily fall into either of 
these categories, although they have some characteristics attributed to one or the 
other of these plants. Although we would not be adverse to considering these 
plants as one complex entity, we have followed their traditional treatment as 
maintained by Fernald. 

Fam. 15. Potamogetonaceae Dum. Pondweed Family 

Aquatic herbs of fresh or sometimes brackish or alkaline water; leaves alternate 
or imperfectly opposite, those immersed thin, those above water often leathery, 
sheathing at the base, the sheath free or partially adnate to the petiole; flowers 
bisexual, small, arranged in pedunculate axillary spikes; peduncle surrounded by 
a sheath at the base; bracts absent; perianth comprised of 4 free rounded shortly 
clawed valvate segments; stamens 4, inserted on the claws of the segments; 
anthers extrorse, 2-celled, sessile; gynoecium of 4 sessile free 1 -celled carpels; 
stigmas sessile or on short styles; ovule solitary, attached to the adaxial angle of 
the carpel, campylotropous; fruiting carpels sessile, free, 1-seeded, indehiscent; 
seeds without endosperm, the embryo with large "foot", the plumule enclosed 
by the cotyledon. 

A family of two widespread genera, the following and Groenlandia. 

1. Potamogeton L. Pondweed 

Annual or perennial aquatic herbs propagated from seeds, winter-buds 
(hibernacula) or rhizomes; stems variable in length according to water depth, 
branched or unbranched, terete or flattened; leaves all submersed or with both 
submersed and floating blades; submersed leaves usually flaccid, sessile or petioled, 
linear or orbicular, acute to obtuse at apex, the margins entire to denticulate or 
serrate, the nerves 1 to 35; stipules fused to form a single structure with 2 
midveins, arising from the axil of the stem and leaf, free or adnate to the leaf 
base, often sheathing the stem and sometimes with the outer margins partially 
fused (connate); floating leaves usually coriaceous, petioled, elliptic to ovate, 
cuneate to rounded or cordate at base, the nerves 3 to 51, the margins entire, the 
stipules like those of submersed leaves but never adnate nor connate; peduncles 
about same diameter as stem, terete, sometimes clavate at tip; inflorescence a 
spike with 1 to 20 whorls of flowers, compact or moniliform, with 2 to 4 flowers 
in each whorl, mostly buoyed above the water surface; flowers bisexual, perianth 
of 4 free rounded short-clawed greenish segments; stamens 4; anthers sessile on 
the claws, 2-celIed, extrorse; carpels 4, free, sessile; fruits dryish drupelets or 
achenes with spongy mesocarp and bony endocarp. one-seeded, embryo coiled, 
cotyledon one, endosperm absent. 

A genus of 90 to 100 species found in all parts of the world, except the polar 
regions, but mostly in the North Temperate areas. Nearly 40 species occur in 
North America, all but one being indigenous; about half of these are widespread, 
common and often locally abundant. 

Pondweeds are found primarily in shallow ponds, lakes and quiet waters of 
rivers and streams, and they are an important element in the ecology of such 
places. The achenes of all our species provide a favorite and important food for 
wildfowl. In addition, plant parts, especially of the more delicate species, are also 
eaten by wildfowl that include most waterfowl, marsh birds and shorebirds. The 
plants are also commonly eaten by muskrats, beaver and deer. The most important 
species, mainly because of its tolerance to brackish water, its abundant seed pro- 
duction, and the edibility of its vegetative parts, is the sago pondweed (P. 
pectinatus). Most of the species provide food, shelter and shade for fish and 
minute animal life. They provide, in particular, an excellent haven for insect life 
that, in turn, provide food for fish. 

95 




Fig. 31: Potamogeton latifoUus: a, interrupted flowering spike, showing the re- 
flexed sepaloid connectives, X 2; b, young branch, X 7-,; c, habit, X 7-,; d, achene, X 6; 
e, achene (longitudinal section), showing tip of curved embryo directed toward base 
of seed. X 6; f-i, sheaths and ligules, showing variation in ligule apices. X IV2; j-1, 
leaf tips, showing variation in apices and venation, X 4. (From Mason, Fig. 15). 



1. Submersed leaves linear, mostly more than 10 times as long as wide (2) 

1. Submersed leaves lanceolate to ovate, mostly less than 10 times as long as 

wide (12) 

2(1). Stipules united with the base of the leaf for a distance of 7 mm. or more; 
floating leaves often absent (3) 

2. Stipules free from the leaf or united for a distance of less than 6 mm. (6) 

3(2). Plants with submersed leaves only; fruiting spikes slender (4) 

3. Plants with long-petioled floating leaves and sessile linear submersed leaves; 

if floating leaves absent the fruiting spikes of submersed parts 

capitate and sessile or on very short peduncles 

9. P. diversifolius. 

4(3). Leaves more than 1 mm. broad, the apex rounded to broadly obtuse and 
apiculate, the veins 3 to 7 1. P. latifolius. 

4. Leaves all linear-filiform, less than 1 mm. broad (5) 

5(4). Stigma disc-shaped, sessile or short-stalked; leaves blunt or submucronate 
2. P. filiformis. 

5. Stigma not discoid, the stigmatic tip prolonged and with little evident swelling; 

leaves acute at the apex 3. P. pectinatus. 

6(2). Floating leaves absent (7) 

6. Floating leaves usually present, with broad blades and long petioles (11) 

7(6). Fruits with dorsal keel prominent, thin, alate, undulate or toothed (8) 

7. Fruits with dorsal keel rounded or acute but never thin and alate (9) 

8(7). Leaves 1.4—2.7 mm. wide, the veins 3 to 5; fruits 2-2.5 mm. long 

5. P. foliosus var. foliosus. 

8. Leaves 0.3-1.5 mm. wide, the veins 1 to 3; fruits 1.8-2.3 mm. long 

5. P. foliosus var. macellus,. 

9(7). Fruits tuberculate (especially at base), 2.5-2.8 mm. long, the lateral keels 
prominent 7. P. clystocarpiis. 

9. Fruits smooth, 2-2.5 mm. long, the lateral keels rounded or obscure (10) 

10(9). Stipules connate when young; peduncles 1.5-8 cm. long; spikes 6-12 mm, 
long, of 3 to 5 separated whorls 6. P. pusillus. 

10. Stipules not connate; peduncles rarely more than 3 cm. long; spikes 2.8 mm. 

long, of 1 to 3 adjacent whorls 

8. P. Berchtoldii var. tenuissimus. 

11(6). Submersed leaves linear, usually bladeless and filiform, 0.8-2 mm. wide; 
blade (when present) linear-lanceolate and on a very long petiole; 

floating leaves broad, many-veined, base of blade subcordate 

15. P. nutans. 

1 1 . Submersed leaves linear to linear-obovate, often very unequal in size, usually 

tapering to tip and base, 3-12 cm. long, to 15 mm. wide 

14. P. gramineus. 

12(1). Leaves mostly all submersed and essentially alike; petioles short or ab- 
sent (13) 

12. Leaves of two kinds, submersed and floating, the floating leaves with broad 

blades and long petioles (14) 

13(12). Leaves broadly lanceolate-attenuate, large, serrulate only at tip 

13. P. illinoensis. 

13. Leaves oblong and crisped, serrulate throughout, rounded at tip 

4. P. crispus. 

14(12). Submersed leaves ovate-lanceolate, arcuately folded or falcate in outline, 
sessile or on short petioles; floating leaves mostly with more than 
30 nerves 11. P. amplifolius. 

97 




Fig. 32: Potamogeton filiformis: a, apical part of plant, showing the fleshy linear 
leaves with adnate stipules sheathing the young leaf blades and the 5 regularly spaced 
flower whorls, X 2; b, habit, X %; c-f, leaf tips, showing variation from blunt to sub- 
mucronate, X 4; g, sepaloid connective, showing pronounced veins, X 8; h, flower, 
X 8; i, achene, showing rounded back and nearly central, wartlike beak, X 8; j, achene 
(longitudinal section), X 8. (From Mason, Fig. 13). 




Fig. 33: Potamogeton pectinatus: a, moniliform spike with mature achenes, X 1%; 
b, habit, showing slender branching stems and linear-filiform submersed leaves, arising 
from rhizome, X %; c, upper flowers of spike, X 4; d and e, variation in achenes 
(usually obliquely ovoid, with a short wartlike beak), d, X 5%, e, X 5; f, achene 
(longitudinal section), X 5; g, stipules sheathing stem or loosely investing it and some- 
what inflated, the linear leaf appearing to originate at the top of the sheath, X 3; h, 
rhizome with winter corm, X lYr,. (From Mason, Fig. 14). 



14. Submersed leaves lanceolate to oblong; floating leaves mostly with fewer than 

30 nerves (15) 

15(14). Floating leaf blades usually cordate, rarely rounded at base, with 21 to 
29 (sometimes more) veins; submersed leaves tapering rather 
abruptly to a sessile base or short petiole to 1.5 cm. long; mature 
fruit light-brown to olive-green, 3-3.5 mm. long 10. P. pulcher. 

15. Floating leaf blades cuneate or rounded at base, with 9 to 21 veins; sub- 

mersed leaves tapering gradually to a petiole 2-13 cm. long; mature 
fruit usually reddish, 3.5-4 mm. long 12. P. nodosus. 

1. Potamogeton latifolius (Robbins) Morong. Western pondweed. Fig. 31. 
Rhizome creeping, rooting freely at the nodes; stem whitish, simple below, 

repeatedly branched above; stele of the one-bundled-type or oblong-type; endo- 
dermis of U-cells; interlacunar bundles present in the outer interlacunar circle; 
subepidermal bundles absent; pseudohypodermis absent or partly 1 cell thick; 
leaves all submersed, linear, entire, green to bronze, rather opaque, to 7 cm. long 
and 7 mm. wide, the apex obtuse to rounded or shortly apiculate to acutish on 
the upper leaves; nerves 3 to 5, with strong crossveins making a rectangular pat- 
tern; stipules prominent, 8-12 mm. long, adnate to the base of the leaf to form a 
broad sheath, hyaline along the margin, the free portion 1-4 mm. long; peduncles 
2-25 cm. long; spikes with 4 to 6 whorls, contiguous when young but soon be- 
coming moniliform; basal internodes 5-12 mm. long, the upper shorter, in fruit 
2-4 cm. long; flowers sessile; perianth semiorbicular, slightly wider than long, to 
5.2 mm. wide; anthers about 1.8 mm. long; fruits obliquely obovate, the sides 
convex but somewhat compressed, 3-4 mm. long, 2-4 mm. wide; dorsal keel 
obscure, lateral keels rounded; beak facial, slightly recurved, about 1 mm. long; 
exocarp olive-green to fulvous; endocarp loop solid or with a spongy area; apex 
of seed pointing above the basal end. 

In quiet or flowing fresh or brackish water, in s.w. Tex. (Cameron, Pecos, 
Reeves and Val Verde cos.) and Ariz. (Mohave Co.), flowers and mature fruit 
from May to Sept.; rare in s.w. U.S. 

2. Potamogeton filifonnis Pers. Fig. 32. 

Slender much-branched wholly submersed plant of brackish waters, with hori- 
zontal stolons bearing white tubers 1-2 cm. long; stipules adnate to leaf and 
sheathing the stem, the sheaths 0.4-2.2 cm. long, connate below, the tips free, 
scarious, 1-5 mm. long; leaves setaceous, to 12 cm. long, 0.2—0.5 mm. wide, blunt; 
peduncles filiform, flexuous, to 1 dm. long; spike moniliform, 1.5-5 cm. long, 
with 2 to 5 whorls, the upper whorls 3-12 mm. apart, the lower ones 0.7-2.5 cm. 
apart; connectives 0.5-1 mm. long; styles almost wanting; nutlets sessile, 2-2.7 
mm. long, 1.5-2 mm. wide, rounded on back, the beak short, wartlike, nearly 
central. 

Ponds, slow streams and ditches in N.M. (Rio Arriba Co.) and Ariz. (Pinal 
Co.), Apr.-Sept.; Greenl. to Alas., s. to Pa., Mich., N.M., Ariz, and Calif.; Euras., 
Afr. and Austral. 

3. Potamogeton pectinatus L. Sago pondweed. Fig. 33. 

Rhizome creeping, much-branched, 1-1.5 mm. in diameter, bearing terminal 
tuberous bulblets; stem terete or slightly compressed, about 1 mm. in diameter, 
mostly simple near base but abundantly branched near summit; stele with the 
oblong pattern or one-bundled in slender branches; endodermis of U-cells; inter- 
lacunar bundles present; subepidermal bundles present or absent; pseudohypodermis 
1 or 2 ceils thick; leaves all submersed, filiform to narrowly linear, entire, to 15 
cm. long and 1 mm. wide, occasionally wider on robust forms, the apex tapering 
to a narrowly acute point (sometimes obtuse on young seedlings); nerves 1 to 3, 

100 




Fig. 34: Potamogeton crispus: a, habit, X %; b, branch with maturing spikes, 
X 7.-,; c, few-flowered spike, X 4; d, young flowering spike, emerging from sheathing 
stipules, X 3; e, winter bud, showing fleshy stems, short internodes and thickened 
foliaceous bud scales with strongly dentate broadened bases, X 1%; f, stem (cross 
section), X 6; g, ligulate stipule, X IV2; h, young leaf, showing venation, X 3, i, 
achene, (longitudinal section), X 6; j, achene, showing the somewhat curved beak and 
variation in the denticulate dorsal keel, X 6. (From Mason, Fig. 21). 




Fig. 35: Potamogeton joUosus: a, spike, showing short clavate peduncle, X 8; b, 
achene, showing the thin undulate-toothed keel, X 10; c, habit, X %; d, fruiting spike, 
showing connate and ruptured stipules, X 4; e, leaf tip, X 8. (From Mason, Fig. 23). 



with strong crossveins, the lateral nerve usually marginal; stipules prominent, 
2-5 cm. long, the base adnate to the leaf to form a sheath slightly wider than the 
stem, greenish or whitish, the free portion less than half the length of the sheath; 
peduncles 3-25 cm. long, flexuous; spikes with 2 to 5 whorls of flowers, soon 
becoming widely and unequally spaced (moniliform), in fruit to 5 cm. long; 
flowers sessile or nearly so; perianth greenish, the blades orbicular to elliptical, 
1-2 mm. wide; anthers 0.5-1 mm. long; fruits obliquely obovate, plump, narrow 
at base, rounded on the dorsal side, 2.5-4 mm. long, 2-3 mm. wide; dorsal keel 
absent, the lateral keels obscure; beak facial, usually recurved, about 0.6 mm. 
long; exocarp light tan. yellowish or pale-olive-green; endocarp loop solid, apex 
of seed pointing toward the basal end or slightly above. 

In alkaline, brackish or saline water of ponds, quiet rivers, marshes and ocean 
shores, often occurring in great masses, in most of Okla., throughout Tex. except 
perhaps the e. Timber Belt and Blackland Prairies, and throughout most of N. M. 
and Ariz., mature fruit from May to Oct.; throughout much of e. half of U. S. 
and Can., w. to Alas., s. to Mex. 

4. Potamogeton crispus L. Curled pondweed. Fig. 34. 

Rhizome buff or reddish, about the same thickness as the stem; stem simple 
or branched, laterally compressed and somewat 4-angled with the broader sides 
furrowed, 0.5-2.5 mm. in greatest diameter; stele of the oblong-type pattern with 
but 1 central bundle and 1 lateral bundle on each side; endodermis of 0-cells; 
interlacunar bundles absent; subepidermal bundles absent; pseudohypodermis 1 
cell thick; leaves all submersed, bright-green to dark-green or occasionally slightly 
reddish, translucent, linear-oblong to linear-oblanceolate, to 1 dm. long and 
1 cm. wide, the apex broadly rounded, the base semiclasping; nerves 3 to 7, the 
laterals close to the margin; lacunae of 1 or 2 rows on each side of midrib; 
margins finely and irregularly dentate and often undulate; stipules 5-15 mm. long, 
slightly adnate at base, the upper part fraying early to leave papery or shreddy 
bases; peduncles 2-7 cm. long; spikes of 3 to 5 whorls of flowers, compact or 
moniliform, in fruit 1-2 cm. long, 1-1.3 cm. wide; flowers sessile or on very 
short pedicels; perianth blades orbicular, 1.2-2.1 mm. wide; anthers 0.7-1.3 mm. 
long; fruits ovate, 2-3.6 mm. long (excluding beak), 1.5-2.8 mm. wide; keels 
obtuse but prominent, the dorsal one strongly developed below and with a small 
tooth near the base; beak prominent, straight or incurved, as long as the fruit 
body; exocarp dark-olive or brownish; endocarp loop solid and near the base; apex 
of seed pointing toward the basal end; winter-buds burlike, hard and horny, 1-2.5 
cm. thick. 

In ponds and streams, often abundant in quiet muddy calcareous water; seldom 
found fruiting but does not produce fruits in shallow warm non-fluctuating water, 
in Okla. (Alfalfa, Choctaw, Comanche, Garfield and Ottawa cos.), Tex. (Dallas, 
Grayson, Hemphill, Randall and Travis cos.), N. M. (Hidalgo and Taos cos.) and 
Ariz. (Yavapai Co.), Apr.-Aug.; nat. of Eur. 

When thoroughly established this species may become a very aggressive weed. 

5. Potamogeton foliosus Raf. Fig. 35. 

Rhizome freely branching, rooting at the nodes; stem subsimple below, much- 
branched above, filiform, laterally compressed, usually without glands at the 
nodes; stele of the one-bundled-type; endodermis of 0-cells; interlacunar bundles 
absent; subepidermal bundles present; pseudohypodermis absent; leaves all sub- 
mersed, narrowly linear, green to bronze, to 1 dm. long and 2.7 mm. wide, 
slightly tapering to a sessile base, entire-margined, acute or subacute at apex; 
nerves 3 to 5, the midrib prominent, without bordering lacunae or with 1 to 3 
rows on each side at the base, lateral nerves joining the midrib 1 to 3 leaf-widths 
below the apex, in broad leaves with 5 nerves the marginal ones may join the 

103 




Fig. 36: Polamogeton pusillus: a, flowering spike, X 6; b, achene, obliquely obovoid, 
smooth, with slightly recurved beak, X 8; c, achene (longitudinal section), X 8; d, habit, 
showing narrowly linear submersed leaves, X %; e, stem (cross section), X 20; f, part 
of stem, showing young tubular stipules in upper part and split disintegrating stipules 
at base, X 2; g and h, winter buds, X I'/j. (From Mason, Fig. 24). 



laterals farther down; stipules 7-18 mm. long, with connate margins when young 
to form tubular delicately fibrous blunt sheaths, soon tearing and deciduous; 
peduncles slightly thickened upward, to 3 cm. long; spikes subcapitate or cylindric, 
of 1 to 3 contiguous whorls of 2 flowers each; perianth blades flabellate, brown- 
ish, 0.6-1 mm. long; fruits obliquely suborbicular, laterally compressed, 2-2.5 mm. 
in diameter; dorsal keel with a thin undulate to dentate wing; lateral keels obscure; 
beak erect, broad at base, 0.2-0.4 mm. long; exocarp fulvous or olive-brown; 
embryo with apex pointing toward the basal end or slightly above; winter-buds 
sessile in the axils or on short branches. 

In fresh (mostly calcareous) or brackish water of ponds, irrigation ditches 
and slow or swift streams throughout most of Okla., Tex., N.M. and Ariz., mature 
fruit from May to Oct.; throughout Can. and the U.S. to Mex. and the W.I. 

Var. macellus Fern. Similar to var. foliosus but smaller and more bushy- 
branched; leaves bright-green, to 7 cm. long and 1.5 mm. wide; nerves 1 to 3; 
midrib without adjacent lacunae or with a single row on each side below the 
middle; fruits green, obliquely obovoid, 1.8-2.3 mm. long, the body longer than 
broad; beak slender, 0.3-0.8 mm. long; winter-buds terminating elongate branches. 
Same habitats as var. foliosus. This poorly-marked variety that differs only in 
size is apparently rare in our region. 

6. Potamogeton pu&illus L. Fig. 36. 

Plants often with winter-bud at base; rhizome absent; stem usually much- 
branched, slender, terete or slightly compressed, usually with a pair of small 
translucent glands at the nodes; branches (late in the season) often terminated by 
winter-buds; stele of the one-bundled-type or oblong-type; endodermis of 0-cells; 
interlacunar bundles absent; subepidermal bundles present; pseudohypodermis 
absent; leaves all submersed, linear to linear-setaceous, entire, light-green, to 7 
cm. long and 3 mm. wide, acute to obtuse at apex; nerves 3 to 5, the lateral 
nerves obscure in narrow extremes, joining the midrib one-half to 2 leaf widths 
below the tip; midrib usually not bordered by lacunae but they are sometimes evi- 
dent on the young uppermost leaves; stipules scarious-membranaceous, 6-17 mm. 
long, clasping the stem and with margins united at base to above the middle, 
this union tearing with age; peduncles axillary, filiform, 1.5-8 cm. long; spikes 
cylindrical, with 3 to 5 separate few-flowered whorls, 6—12 mm. long; flowers 
with perianth round-flabelliform and with slender claw, 1.2-2 mm. long; anthers 
0.5-0.8 mm. long; fruits obliquely obovoid, 1.9-2.8 mm. long, 1-1.8 mm. wide; 
dorsal keel obscure, very low and broad; lateral keels absent; beak facial, promi- 
nent, erect or slightly recurving, 0.2-0.6 mm. long; exocarp olive-green, smooth; 
endocarp loop solid; apex of seed pointing slightly above the basal end or between 
the base and the middle of the opposite side. 

In neutral or slightly alkaline or slightly brackish water of ponds and rivers, 
often forming large masses, in Okla. (Beaver Co.), throughout Tex., in N.M. 
(Colfax, Rio Arriba and Sandoval cos.) and Ariz. (Apache, Coconino and Santa 
Cruz COS.), mature fruit from May to Oct.; throughout much of U.S. and Can., 
s. to e. Mex.; Euras. 

7. Potamogeton clystocarpus Fern. Fig. 37. 

Stem much-branched, slender, terete or slightly compressed, usually with a 
pair of small translucent glands at the nodes; stele of the one-bundled-type; 
endodermis of 0-cells; interlacunar bundles absent; subepidermal bundles present; 
pseudohypodermis absent; leaves all submersed, linear, entire, light-green, trans- 
lucent to subopaque, to 9 cm. long and 3 mm. wide, the acute apex often with a 
sharp mucro; nerves 3 (5), often obscure, laterals joining the midrib near the 
apex or disappearing in the apical area; midrib bordered on each side by one or 
two rows of lacunae; stipules hyaline to subherbaceous, 0.5—1 mm. long, usually 

105 







Fig. 37: Potamogeton clystocarpus: a, upper portion of leaf to show venation and 
apex, X 5; b, portion of plant to show free margins of stipule, X IV-r, c, fruit, X 10; d, 
fruit cut to show coil of embryo, X 10. 



clasping the stem but with margins free, becoming lacerate at the apex; peduncles 
filiform, 15-65 mm. long; spikes short-cylindric, 8-10 mm. long, with 2 or 3 
whorls of flowers; flowers with perianth broad-flabelliform and with slender claw, 
2.5-3 mm. long, 1.5-2.5 mm. wide; anthers 0.8-1.2 mm. long; fruits obliquely 
obovate to suborbicular, with 2 or more verrucose protuberances near the base, 
2.5-2.8 mm. long, 1.8-2 mm. wide; dorsal keel rounded to prominently developed 
and gibbous at base; lateral keels rounded or obscure; beak facial, recurved, 0.2- 
0.5 mm. long; exocarp dark-olive-green; endocarp loop solid; apex of seed point- 
ing slightly above the basal end or between the base and the middle of the opposite 
side. 

In quiet pools and flowing streams, known only from Little Aguja Canyon, 
Davis Mts., Jeff Davis Co., Tex., where it is endemic, in fruit from May to Oct. 
and perhaps later. 

8. Potamogeton Berchtoldii Fieb. var. tenuLssimus (Mert. & Koch) Fern. Fig. 38. 

Plants often with winter-bud at base; rhizome absent; stem usually much- 
branched, slender, terete or nearly so, usually with a pair of small translucent 
glands at the nodes; branches (late in the season) often terminated by winter- 
buds; stele of the one-bundled-type; endodermis of 0-cells; interlacunar bundles 
absent; subepidermal bundles present; pseudohypodermis absent; leaves all sub- 
mersed, linear to linear-setaceous, acute at apex, entire, light-green to deep-green, 
translucent and flaccid, to 85 mm. long and 1 mm. wide; nerves 3, laterals often 
obscure and (when not evanescent) joining the midrib one-fourth to 2 leaf-widths 
below the tip; midrib bordered on each side (at least in the lower half) by a single 
row of lacunae; stipules hyaline to subherbaceous, 3-14 mm. long, usually clasping 
the stem but with margins free (or adhering because of adhesive materials in the 
water); peduncles axillary, filiform, to 3 (rarely -4.5) cm. long; spikes sub- 
globose, with 1 to 3 few-flowered whorls, 2-8 mm. long; flowers with perianth 
round-flabelliform and with slender claw, 1-2 mm. long; anthers 0.5-0.8 mm. 
long; fruits obliquely obovoid, 2-2.5 mm. long, 1.2-1.9 mm. wide; dorsal keel 
obscure, very low and broad; lateral keels absent; beak facial, prominent, erect 
or slightly recurving, 0.1-0.5 mm. long; exocarp dark-olive-green, smooth or 
faintly rugulose when dry; endocarp loop solid; apex of seed pointing slightly 



106 




Fig. 38: Potamogeton Berchtoldii: a, habit, showing dense, short, somewhat spread- 
ing leaves, X %; b, young flowering spike surrounded by sheathing stipules, X 5; c, 
sepaloid connective, X 12; d, habit of a plant with leaves longer and more linear- 
setaceous than those of plant in a, X %; e and f, typical leaf tips, showing venation, 
X 8; g, achene (longitudinal section), x 12; h, achene, showing the rounded obscurely 
keeled back and the marginal erect beak, X 12; i, winter bud, X 2. (From Mason, 
Fig. 25). 



above the basal end or between the base and the middle of the opposite side. 

In neutral to acid water of ponds and rivers in Okla. (Waterfall), n.e. Tex. 
(Bowie Co.), N. M. (Rio Arriba Co.) and Ariz. (Coconino Co.), May-Oct.; 
throughout much of N. A. 

9. Pofamogeton diversifolius Raf. var. diversifolius. Fig. 39. 

Rhizome freely branching, rooting at the nodes; stem filiform, terete, much- 
branched; stele of the oblong-type with one or two median bundles; endodermis of 
0-cells; interlacunar bundles absent; subepidermal bundles absent or occasionally 
with faint mechanical strands; pseudohypodermis present or absent; submersed 
leaves narrowly linear, entire, pale-green, mostly 2-6 cm. long, 0.5-1.5 mm. wide, 
slightly tapering to a sessile base, acute to obtuse at apex; nerves 3, laterals in- 
conspicuous; midrib usually bordered by 1 to 4 rows of lacunae; stipules delicately 
fibrous, adnate to the base of the leaf blade; floating leaves coriaceous, elliptic to 
oval or narrowly obovate, rounded at apex, cuneate or rounded at base; petioles 
usually shorter than the blades; blades to 4 cm. long and 2 cm. wide; nerves 5 
to 15; stipules free from the petioles, 6-30 mm. long, delicately fibrous, persistent; 
peduncles usually slender, often clavate, 1-^ mm. long from the axils of submersed 
leaves and 2—30 mm. long from the axils of floating leaves, ascending or arching; 
submersed spikes few-flowered, subglobose; emersed spikes elongate, 5-20 mm. 
long, in fruit 3-4 mm. wide; flowers sessile or nearly so; perianth suborbicular to 
broadly rhombic, 0.7-1 mm. long, with a short claw; fruits suborbicular, the sides 
flattened or slightly concave and often cochleate-sulcate, 1—1.5 mm. in diameter; 
dorsal keel prominent, alate, 0.2-0.4 mm. wide, undulate or with a few very low 
teeth; lateral keels low and fine but evident, entire or slightly dentate; beak facial, 
minute but usually definite; exocarp greenish to brownish, endocarp with loop 
solid; embryo coil more than one complete revolution; winter-buds may form 
late in the growing season, being short branches with crowded internodes. 

In pools, tanks and small streams, throughout most of Okla., common in e. 
Tex. and in the mts. of the Trans-Pecos to Ariz. (Coconino Co.), freely fruiting 
throughout the summer; mostly in s. U.S. and Mex. 

Var. trichophyllus Morong. Similar to var. diversifolius except submersed 
leaves flaccid, setaceous or setaceous-linear, 0.1-0.6 mm. wide, tapering to an 
acute r x, the nerves 1 or obscurely 3; stipules delicate, free or partially adnate 
to the oase of the leaf blade, deciduous with age; floating leaves lance-elliptic 
to oval-elliptic, acutish or (if rounded) at least submucronate at apex; blades 
7-26 mm. long. 1—10 mm. wide; nerves 3 to 9; stipules 3-10 mm. long; peduncles 
1-4 mm. long from the axils of submersed leaves and 2-30 mm. from the axils 
of the floating leaves; fruits with dorsal keel entire or with 3 to 12 small teeth. 
In the same habitats as var. diversifolius. 

10. Potamogeton pulcher Tuckerm. Fig. 40. 

Rhizome pale-buff", often with dark-red spots; stem simple, terete, 1-2.5 mm. 
in diameter, usually conspicuously dark-spotted; stele with the prototype pattern; 
endodermis of 0-cells; interlacular and subepidermal bundles absent; pseudo- 
hypodermis mostly 1 cell thick; submersed leaves of two intergrading types, those 
of the lower part of the stem semiopaque and oblong with rounded apices, those 
of the upper part of the stem translucent and lanceolate to lance-linear, with an 
acutish but not sharp-pointed apex, both types tapering at base to petioles to 35 
mm. long; blades entire, to 18 cm. long and 35 mm. wide, usually smaller; nerves 
11 to 21, the outer ones marginal; lacunae 4 to 8 rows on each side of midrib; 
floating leaves coriaceous, ovate to rotund, rounded to bluntly mucronate at apex, 
cordate or rounded at base; petioles 4-18 cm. long; blades to 11 cm. long and 
85 mm. wide, with 19 to 35 nerves; stipules of the submersed leaves decaying 
early, those of the floating leaves persistent, narrowly triangular, obtuse when 

108 




Fig. 39: Potamogeton diversifolius: a and b, achenes, showing the angular often 
denticulate outline of the dorsal keel and the strongly coiled embryo, X 16; c, upper 
part of stem, the floating leaves elliptic, the submersed leaves linear, X 2; d, habit, 
showing the numerous capitate subsessile spikes, X %, e and f, tips of submersed leaves, 
X 10; g, linear leaf blade arising from stipule, and the long free ligule, X 4; h, mature 
capitate spikes, showing reflexed peduncles in axils of submersed leaves, X 2; i, flowers 
in spike, X 8. (From Mason, Fig. 17). 




Fig. 40: Potamogeton pulcher. a, habit, X %; b, flower, X 5; c, achene, X 5; d, 
coil of embryo, X 5. (Courtesy of R. K. Godfrey). 



young, acutish with age, 2-5 cm. long, 2-keeled; peduncles 5-1 1 cm. long; spikes 
with about 10 whorls, in fruit 2-3.5 cm. long, 8-11 mm. thick; flowers sessile or 
nearly so; perianth greenish, blades orbicular to elliptical and 1.2—3 mm. wide; 
anthers 0.8-1.4 mm. long; fruits obliquely ovate, rounded or cuneate at base, the 
sides flat or slightly concave, 2.7-4 mm. long, 2.3-3.4 mm. wide; keels usually 
prominent, acutish, the dorsal one often strongly developed and sometimes with 
a basal lobe projecting below the point of attachment; beak often prominent, to 
0.8 mm. long; exocarp light-brown to olive-green; endocarp with 3 prominent 
acutish and somewhat muricate keels; beak linear, facial, about 1 mm. long; loop 
solid; apex of seed pointing 0.5-1.2 mm. above the basal end. 

In muddy pools, boggy streams, lakes and occasionally in clear water in sandy 
bottoms in Okla. (McCurtain, Payne and Pushmataha cos.) and in Tex. mostly 
in the Timber Belt^ flowers in Apr. and May, mature fruit by mid-May; in the 
e. half of U. S. 

11. Potamogeton amplifolius Tuckerm. Fig. 41. 

Plant froni stout rhizomes; stems simple or branched near the top^ often rufous; 
submersed leaves variable, from short-lived (lanceolate and short-petioled) to 
persistent (broadly lanceolate to ovate and folded along the midvein), the blade 
8-20 cm. long, 25-75 mm. broad, tapering to petiole 1-6 mm. long, the stipules 
becoming fibrous and stringy, 3-10 cm. long; floating leaves similar to the upper 
submersed leaves to ovate or elliptic, round-tipped, rounded or tapering to the 
base, 5-10 cm. long, 25-50 mm. wide, the stipules usually 2-keeled; peduncles 
often thickened apically, 5-11 cm. long; spikes with 9 to 16 whorls of flowers, 
4-8 pm. long when mature; nutlets 3-5 mm. long, obovate, rounded on back, 
cuneate at base, the sides flat, the beak prominent. 

Lakes, ponds, still water of creeks, at middle and lower altitudes, in rather deep 
water, in Okla. (Comanche, McCurtain and Osage cos.), Apr.-Sept.; from Nfld. 
to B. C, s. to Va., Ark., Okla., and Calif. 

12. Potamogeton nodosus Poir. Fig. 42. 

Rhizome white, suffused or spotted with rusty red; stem simple, terete, often 
pressing very flat, 1-2 mm. in diameter; stele with the triotype pattern, with the 
phloem on the inner face of the trio-bundle appearing as one patch; endodermis 
of 0-cells; interlacunar and subepidermal bundles absent; pseudohypodermis 
absent; submersed leaves thin, linear-lanceolate to broadly lance-elliptic, to 2 dm. 
long and 35 mm. wide, tapering gradually at base into a petiole 2-13 cm. long, 
tapering gradually to an acutish but not sharp-pointed apex; nerves 7 to 15; 
lacunae of 2 to 5 rows along the midrib; margin of young blades with fugacious 
translucent denticles; floating leaves coriaceous, with long petioles; blades lenticu- 
lar to elliptic, cuneate or somewhat rounded at base, acutish to rounded at apex 
and sometimes with an obtuse mucro, to 11 cm. long and 45 mm. wide; nerves 
9 to 21; lacunae rarely present; stipules of submersed leaves brownish, often 
delicate and decaying early, linear, acute or obtuse, 3-9 cm. long, those of the 
floating leaves similar but usually broader at base and more or less 2-keeled; 
peduncles usually thicker than the stem, 3-15 cm. long; young spikes compact 
but becoming loose at anthesis, of 10 to 17 whorls of flowers, at maturity usually 
not densely fruited, 3-7 cm. long, 8-10 mm. thick; flowers sessile; perianth 
greenish or brownish, orbicular or elliptical, 1.4-2.6 mm. wide; anthers 1-1.4 mm. 
long; fruits obovate, 3.5-4.3 mm. long, 2.5-3 mm. wide; keels prominent, the 
dorsal strongly developed (especially upward), the laterals often muricate; beak 
facial, short; exocarp of mature fruits brownish or reddish; endocarp with keels 
strongly developed, the dorsal often 0.5 mm. wide, the laterals strongly muricate; 

111 




Fig. 41: Potamogeton amplifolius: a, upper part of stem, showing floating leaves, 
the stout upwardly thickened peduncle and acute stipules, X -/-,; b, habit, showing 
rhizome, arcuate submersed leaves, broad stipules and densely whorled flowers, X %; 
c, sepaloid connective, X 6; d, achene (longitudinal section), X 6; e, achene, showing 
the flat sides and prominent beak, X 6; f, single tlower, X 6 (From Mason, Fig. 27). 




Fig. 42: Potamogeton nodosus: a, submersed leaf, X %; b, rhizome and young 
shoot, showing stipules and attenuate scales, X %; c, venation in submersed leaf blade, 
X 2; d, upper part of stem, showing elliptic long-petioled floating leaves, X %; e, achene, 
showing strongly developed dorsal and lateral keels and sculptured surface, X 8; f, 
spike, X 4. (From Mason, Fig. 28). 



beak linear, erect, to 1 mm. long; loop solid; apex of seed pointing a little above 
the basal end. P. americanus Cham. & Schlecht. 

In streams and lakes throughout Okla. and Tex. to N. M. (Colfax, Sandoval 
and San Miguel cos.) and Ariz. (Coconino, Gila, Maricopa, Navajo and Yavapai 
COS.), mature fruits in late spring and summer; in much of the U. S., Can. and 
n. Mex. 

13. Potamogeton Ulinoensis Morong. Fig. 43. 

Rhizome buff, spotted or suffused with red; stem simple or branched, terete, 1-5 
mm. in diameter; stele with the prototype, triotype or oblong-type pattern; endo- 
dermis of U-cells; interlacunar bundles in the outer interlacunar circle, sometimes 
a few in the next to the outer circle; subepidermal bundles present or absent; 
pseudohypodermis absent or of 1 cell thick; submersed leaves thin, elliptic to 
lanceolate, often somewhat arcuate; blades to 2 dm. long and 45 mm. wide, sessile 
or tapering into a petiole to 4 cm. long, acute and usually somewhat mucronate at 
apex; nerves 7 to 19; lacunae of 2 to 5 rows along midrib and larger nerves; 
margin entire or with fugacious 1 -celled translucent denticles; floating leaves 
(often absent) more or less coriaceous, transition to submersed leaves usually 
gradual; blades elliptic to ovate-elliptic or oblong-elliptic, to 19 cm. long and 65 
mm. wide, obtuse-mucronate at apex, cuneate or rounded at base; petioles 2-9 cm. 
long, shorter than the blade; nerves 13 to 29; lacunae of 2 or 3 rows of cells 
along midrib, sometimes obscure; stipules persistent, divergent and conspicuous, 
obtuse, those of the submersed leaves 1-8 cm. long and 3-12 mm. wide at base, 
prominently 2-keeled, with 15 to 35 finer nerves; those of the floating leaves 
broader; peduncles as thick as or thicker than the stem, 4-30 cm. long; spikes in 
anthesis compact, of 8 to 15 whorls of flowers, at maturity cylindric and crowded, 
2.5-7 cm. long, 8-10 mm. thick; flowers sessile or on pedicels to 0.5 mm. long; 
perianth orbicular to oval, 1.3-3.2 mm. wide; anthers 0.6-2 mm. long; fruits 
obovate to orbicular or ovate, 2.5-3.6 mm. long (excluding beak), 2.1-3 mm. 
wide, the sides flat; keels prominent and acute, the dorsal strongly developed 
above and below, the laterals less strongly developed but often each with a pro- 
jecting knob at the base; beak facial, short, erect or curved toward the back; 
exocarp gray-green to olive-green or brownish, sometimes reddish; endocarp with 
keels low but prominent or with dorsal keel thin and very weak; beak deltoid and 
weak, about 0.5 mm. long; loop solid; apex of seed pointing at the middle of the 
opposite side or between middle and base. P. lucens L., P. angustifolius Bercht. 
& Presl. 

In quiet or flowering water of ponds, canals and rivers in s.-cen. Tex., especially 
on the Edwards Plateau and in the Guadalupe Mts., w. to N. M. (Eddy Co.) and 
Ariz. (Coconino Co.), fruiting by early May; throughout much of U.S. and Can. 

A variable species due, in part, to habitat. Hybrids may occur between this 
species and P. nodosus, especially where the two are found together. 

14. Potamogeton gramineus L. Fig. 44. 

Plant from a mass of rhizomes; stems slender, occasionally fistulose, 2-15 dm. 
long; submersed leaves abundant, typically sessile (occasionally petioled), linear 
to lanceolate or oblanceolate, 3-12 cm. long, 1-15 mm. wide, acute and often 
with a short-attenuate tip, the stipules persistent; floating leaves on slender petioles, 
the blades ovate to elliptic, 1.5-7 cm. long, 1-3 cm. broad, usually shorter than 
petioles; stipules lanceolate, somewhat keeled, persistent, 5-30 mm. long; pe- 
duncles stout, 2-10 cm. long; spikes compact, 1-4 cm. long when mature; nutlets 
obovate, 1.5-3 mm. long, obscurely keeled, the beak somewhat recurved. 

Ponds, lakes, marshes and sluggish streams in N.M. (San Juan and Sandoval 
cos.) and Ariz. (Coconino and Maricopa cos.), May-Sept.; Greenl. to Alas., s. to 
Pa., N. Y., 111., la., N.M., Ariz, and Calif.; Euras. 

114 




Fig. 43: Potamogeton illinoensis: a, habit, showing profusion of crowded leaves, 
conspicuous stipules and long stout peduncles, X %; b, part of flowering spike, X 4; c, 
achene, showing strong dorsal keel, smooth face and short beak, X 6; d, achene 
(longitudinal section), X 6. (From Mason, Fig. 20). 




Fig. 44: Potamogeton gramineus: a, tip of compact flowering spike, X 4; b, keeled 
stipules on flowering branch, X 1%; c, submersed lower part of stem, showing the 
sterile branches with leaf variations and the young stipules clasping the stem, X %; d, 
upper part of stem, showing submersed as well as floating leaves, X 7-,; e, achene with 
obscure keels, X 8; f, submersed foliage, showing transitional forms, X l^f,; g, young 
linear leaf, showing venation and tip, X 3. (From Mason, Fig. 31). 



15. Potamogeton natans L. Broad-leaved pondweed. Fig. 45. 

Stems branching from a horizontal rhizome, otherwise usually simple; sub- 
mersed leaves without blades, 1-3 dm. long. 0.8-2 mm. wide, rarely with a 
poorly developed blade, the linear stipules 6-8 cm. long; floating leaves broadly 
elliptic to oblong, often subcordate at base, broadly rounded at apex, 25- to 27- 
nerved, the petiole longer than blade, the stipules 5-12 cm. long, linear-lanceolate, 
membranous; spikes in the axils of floating leaves, 3-6 cm. long on stout pe- 
duncles, P/i to 3 times as long as the spike; nutlets 3-5 mm. long, strongly keeled 
on the back, the lateral angles scarcely evident, the beak erect. 

Marshy ponds and lakes, often brackish, in Okla. (Choctaw Co.), N. M. (San 
Juan and Sandoval cos.) and Ariz. (Apache and Coconino cos.), May-Sept.; 
Greenl. to Alas., s. to N. J., Pa., O., Ind., 111., la.. Neb., N.M., Ariz, and Calif. 



A sterile specimen in the U. S. National Herbarium might possibly be P. 
alpinus Balbis. It was collected by R. O. Studhalter, etc. (S3874) at Glacial Lake 
near Tres Ritos, Taos Co., New Mexico, at 9,500 ft. elevation. It is distinguished 
from P. amplifolius, which it superficially resembles, by its usually smaller, sessile, 
submersed leaves, more slender rhizome and usually reddish stems and peduncles. 
Its floating leaves, when present, are also delicate and thin with no sharp distinc- 
tion between blade and petiole. 

Fam. 16. Zannichelliaceae Dum. Horned Pondweed Family 

Submerged aquatic dioecious or monoecious herbs, with a slender creeping 
rhizome; leaves alternate or opposite or crowded at the nodes, linear, sheathing 
at the base, the sheaths mostly ligulate at the apex, the floral leaves sometimes 
reduced to sheaths; flowers minute, bisexual or unisexual, axillary, solitary or in 
cymes; perianth of 3 small free scales or absent; stamens 1 to 3, the anthers 1- or 
2-celled and opening lengthwise; pollen globose or threadlike; gynoecium of 1 to 
9 free carpels; style short or long, simple and with a capitate to peltate or spatu- 
late stigma, sometimes 2- to 4-lobed; ovule solitary, pendulous; fruiting carpels 
sessile or stipitate, indehiscent; seed pendulous, without endosperm. 

Widely distributed, mainly in salt or brackish water; 3 genera and 6 species. 

1. Pollen spheroid; carpels several, free; plants of fresh or brackish water; leaves 

filiform 1. Zannichellia 

1. Pollen threadlike; gynoecium 1- or 2-carpenate; plants of marine habitats (2) 

2(1). Leaves flat, tridentate at apex; styles simple; one anther attached higher 
than the other 2. Halodule 

2. Leaves terete or semiterete, acute or pointed at apex; styles 2- to 4-lobed; 

anthers at an equal height 3. Cymodocea 

1. Zannichellia L. Horned Pondweed 

A genus of two species, the other in Africa. Placed by some authors in the 
Najadaceae. 

1. Zannichellia palustris L. Common poolmat. Fig. 46. 

Submerged aquatic plant, monoecious, rooted on bottom and floating below 
surface of water; rhizome creeping; stem slender, simple or much-branched; leaves 
mostly opposite, linear-filiform, entire, to 1 dm. long, acute or almost pungent 
at the apex, 1 -nerved; stipules scarious, free from the leaf bases, scarcely 2 cm. 
long; flowers unisexual, sessile, usually both kinds from the same axil, enclosed in 
a hyaline deciduous spathe, the perianth wanting; staminate flower consisting of 

117 




Fig. 45: Potamogeton tiatans: a, achene (longitudinal section), X 6; b, flower, X 4; 
c, habit, showing the long linear submersed leaves and broadly elliptic floating leaves, 
and the linear-lanceolate stipules, X %; d, achene, showing strong keel on the back, 
X 6. (From Mason, Fig. 29). 




Fig. 46: Zannichellia palustris: a, branch with submersed filiform 1 -nerved leaves, 
showing stipular sheaths and flowers in lower axil, the staminate flower comprised of a 
single stamen arising at the base of the short stout peduncle which bears 4 (usually 
2 to 5) pistils arrounded by a spathe, X 4; b, fruit (longitudinal section), X 8; c, in- 
volucre or spathe with 2 young pistillate flowers and a single staminate flower, all from 
the same axil, X 16; d, habit, showing the long opposite filiform submersed leaves and 
maturing fruits in the axils, X %; e, fruit, showing toothed ridges as revealed by normal 
deterioration of outer coat in old fruits, X 8; f and g, mature undried fruits before 
deterioration of coat, X 8. (From Mason, Fig. 37). 



a single 2- to 4-celled anther on a slender filament; pistillate flowers sessile at 
first, often pedicellate after anthesis; carpels 2 to 8, flask-shaped, ribbed or toothed 
on the margins, or sometimes smooth; style recurved, persistent; mature fruit 
2-4 mm. long, rarely pitted, flattened, slightly incurved, smooth or slightly 
dentate on the convex back, the body 2-3 mm. long, the beak to 1.5 mm long. 

In fresh or brackish water in pools, marshes, streams and irrigation canals, 
in Tex. mainly in the Edwards Plateau and in the Trans-Pecos but widespread in 
Okla., N.M. and Ariz., Apr.-Sept.; nearly throughout N. A., except the extreme 
n., also S. A., Euras. and Afr. 

The fruits as well as the foliage are eaten by wildfowl, the fruits by some 
marshbirds and shorebirds, and the plants are considered to be a fair food 
producer for trout. 

2. Halodule Endl. 

Several species of marine waters mainly in tropical regions. 
1. Halodule Beaudettei (den Hartog) den Hartog. Fig. 47. 

Submerged dioecious perennial, with creeping rootstocks; rootstocks branching, 
articulated and rooting at the nodes, the roots often terminating in fleshy starchy 
tuberlike swellings, with a short erect stem at each node; internodes 5—40 mm. 
long; scales elliptic, 5-10 mm. long; sheaths 1.5-6 cm. long; leaves mostly 
crowded on short erect lateral branches, all linear, grasslike, more or less 
narrowed and sheathing at the base, 5-20 cm. long, 0.8-1.2 mm. wide, midrib 
conspicuous, widening and often furcate near the tip; leaf tip with a very promi- 
nent acute median tooth which is 1 to 10 times as long as the narrow linear lateral 
teeth; flowers without perianth, subtended by a hyaline perianthlike bract; 
staminate flowers consisting of two anthers on the end of a stout stalk; anthers 
oblong, about 4 mm. long, unequally attached, 2-celled; pistillate flowers of 2 
unequal carpels on a stout stalk, the largest carpel about 3.5 mm. long (including 
the single elongate-attenuate style). Diplanthera Beaudettei den Hartog, D. 
Wrightii of auth., Halodule Wrightii of auth. 

In salt water of bays along the Gulf Coast in Tex., frequent in sea drift; 
widely distributed in the Carib. and also in the Gulf of Mex., along the Atl. 
Coast of N.A. n. to N.C.; also along the Pac. Coast of Pan. and Nic. 

3. Cymodocea Konig 

Several species of marine waters mainly in tropical regions. Sometimes placed 
in a separate family, Cymodoceaceae. 

1. Cymodocea fiiiformis (Kiitz.) Correll. Manatee-grass. Fig. 48. 

Submerged acaulescent dioecious perennial, with creeping rootstocks branching 
and rooting at the nodes; leaves all submerged, grasslike, terete or semiterete, 
acute at the apex and sheathing at the base, the sheaths more or less auriculate, 
to 35 cm. long and 2 mm. wide; stipular sheaths completely surrounding the leaf 
bases, scarious, to 45 mm. long; flowers unisexual, solitary or in simple or 
dichotomous cymes; staminate flowers consisting of two anthers on the end of 
a long pedicel, the anthers equally attached, both the same height, 2-celled; 
pistillate flower of 2 carpels, without perianth but subtended by a hyaline peri- 
anthlike bract; style 2- to 4-lobed; stigmas 2, hairlike; mature fruit 1 -seeded, 
3 mm. long, beaked by the persistent style. Cymodocea manatorum Asch., 
Syringodium filiforme Kiitz. 

In shallow salt water of bays along the Gulf Coast of Tex., frequent in sea 
drift; from Fla. and Tex. to Berm., Cuba and Martinique, 

120 





Fig. 47: Halodule Beaudettei: a, habit, x V^; b, enlarged fleshy root; c, sheath, X 5; 
d, enlarged tips of leaves; e, staminate flower, X 5; f, pistillate flower, X 5. (a, e, t, 
Courtesy of R. K. Godfrey, b, c, d, V. F.) 




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Fam. 17. Ruppiaceae Hutchins. Ditch-grass Family 

Aquatic herbs of brackish or saHne waters; stems simple or branched, sub- 
merged; leaves opposite or alternate, linear or setaceous, with a stipular sheath 
at the base; flowers perfect, small, few, arranged in terminal spikes that are 
at first enclosed by the sheathing leaf bases, at length much-elongated to the 
surface of the water; bracts absent; perianth wanting; stamens 2, opposite each 
other, with very short broad filaments; anthers extrorse, the 2 cells reniform 
and separated by the connective; carpels 4, with peltate or umbonate stigmas; 
ovule solitary, pendulous from the apex of the carpel, campy lotropous; nutlets 
long-stipitate, with spirally twisted stalks, indehiscent; seeds pendulous, without 
endosperm. 

Only one genus distributed throughout temperate and subtropical regions. 

1. Ruppia L. 

Characters of the family; 2 species. 

1. Ruppia maritima L. Widgeon-grass. Fig. 49. 

Stem whitish or green, to 1 m. long; leaves all submerged, threadlike, entire, 
1-nerved, to 1 dm. long and 0.3 mm. wide, with a sharp pointed or more or less 
pungent apex; stipular sheath 6-10 mm. long, membranous, the free part very 
short or wanting; flowers on a short peduncle that elongates after anthesis and 
ultimately becomes a loosely coiled spiral; stamens without a filament, early 
deciduous; anthers 2, sessile, 2-celled; mature carpels ovoid, equilateral or gibbous 
and oblique, about 2 mm. long, long-stipitate; style short and stout or finely 
attenuate, straight or hooked; pedicellate stipe of the black nutlet to 3 cm. long. 

On the Tex. Gulf Coast and in saline waters of pools, rivers and marshes in 
the interior to Okla. (Alfalfa Co.), N.M. (Chaves Co.) and Ariz. (Maricopa, 
Mohave and Navajo cos.), Apr. -Aug.; from Can. s. to Mex. 

This species is considered to be one of the most valuable of all submerged 
aquatics, especially in saline habitats, for the maintenance of wild life. It 
provides excellent food and cover for fish, and all parts of the plant, including 
its rootstock and stems, are relished by many species of waterfowl, while marsh- 
birds and shorebirds eat its fruit and foliage. 



Fam. 18. Najadaceae Juss. Water-nymph Family 

Submerged annual monoecious or dioecious herbs of fresh or brackish waters, 
with fibrous roots; stems slender, much-branched; internodes spiny or unarmed; 
leaves small, sessile, subopposite to somewhat alternate or verticillate, with a 
sheathing base and linear entire or toothed blade; within the sheath a pair of 
minute scales; flowers unisexual, very small, borne at the base of the branches; 
staminate flowers with 1 stamen, mostly subsessile and included in a spathe, the 
perianth bilabiate at the apex; anther sessile, 1- to 4-celled, opening by slits 
lengthwise; pistillate flowers without a perianth or this very thin and adhering 
to the carpel; ovary of 1 carpel, 1 -celled, with 2 to 4 linear stigmas; ovule 
solitary, erect from the base, anatropous; nutlet usually embraced by the leaf 
sheath, indehiscent, enclosed in a loose and separable membranous coat, smooth 
and shining or reticulate with angled or roundish areolae. 

Contains only the following genus and about 50 species widely distributed in 
temperate and warm regions. 

123 




Fig. 49: Ruppia maritima: a and b, variations in habit, the stems sometimes very 
long and slender or sometimes with short fractiflex nodes, X %; c, peduncle bearing 2 
young flowers, each consisting of 2 large bicellular anthers and 4 pistils, X 8; d, 2 
flowers, after fertilization, X 8; e, development of the long-pediceled fruits following 
fertilization of the 2 flowers( note elongate, coiled peduncle), X 2; f, mature nutlet, 
hard and black, X 8; g, 2 stipular sheaths of the alternate capillary succulent leaves, 
X 2; h, habit variation, X %; i, serrate leaf tip, X 20. (From Mason, Fig. 32). 




Fig. 50: Najas marina: a-c, development of anther: a, anther enclosed in sessile 
spathe in leaf axil, X 8; b, anther beginning to elongate and rupture spathe, X 8; c, 
mature anther, showing short filament, X 8; d, habit, showing the stems beset with 
prickles, and the spiny-toothed leaves, X 1%; e, mature pistillate flower, showing the 
3 stigmas and the intravaginal scales at base, X 8; f, mature seed, X 10: g, leaf blade, 
showing the coarse, spiny-toothed margins, the spines on the outer side along the 
midrib, and the rounded shoulders of the leaf sheaths, X 6. (From Mason, Fig. 33). 



1. Najas L. Water-nymph 

Characters of the family. 

The species in this genus, along with those in Potamogeton, are considered 
by knowledgeable wildlife personnel to provide the most important source of all 
foods for wildfowl, marshbirds and shorebirds. Ducks and other waterfowl not 
only eat the seeds but also the stems and leaves of most of the species. The 
species are also considered to be good food producers for fish and to provide 
shelter. 

1. Male and female flowers on different plants; leaves coarsely toothed; inter- 
nodes and back of the leaf spiny 1. N. marina. 

1. Male and female flowers on same plant; leaves minutely denticulate; internodes 

and back of leaf unarmed (2) 

2(1). Seeds dull, with distinct squarish pitted reticulations; leaves tapered for 
2-3 mm. to an acute to obtuse apex 2. TV. guadalupensis. 

2. Seeds apparently smooth and shining (but finely reticulate under magnifica- 

tion); leaves tapered from near middle to a long slender point 

3. N. fiexilis. 

1. Najas marina L. Holly-leaved water-nymph. Fig. 50. 

Plants brittle; stems branched, sometimes dichotomously so, armed with 
brownish spinulose teeth on the internodes; leaves linear, opposite to somewhat 
alternate, stiffish or recurved, to 45 mm. long and 3 mm. wide, with toothed 
margins and sometimes dorsally toothed on the midrib, the usually triangular 
teeth apiculate and 1 mm. long or more; basal leaf sheaths rounded, without 
teeth or rarely with a few short teeth; male and female flowers on different plants; 
staminate flowers 3-4 mm. long, the anther 4-celled; pistillate flowers 3-4 mm. 
long; stigmas 3, sometimes one shorter than the others; mature seeds ovoid, 
apparently tesselated in dried specimens, smooth when fresh. 

In lakes and ponds, rare in s. Tex. and Ariz. (Mohave, Navajo, Pima, Santa 
Cruz and Yuma cos.), May-Sept.; from N.Y. to Cahf., s. to Fla., Tex., Ariz., 
Mex. and Cuba; also Euras. and Austral. 

2. Najas guadalupensis (Spreng.) Magnus. Common water-nymph. Fig. 51. 

Plants monoecious, flaccid; stems slender, branched, to about 6 dm. long; 
leaves all submerged, linear, to 25 mm. long and 2 mm. wide, tapered for 2-3 
mm. to an acute to obtuse apex and usually tipped with 1 or 2 spines, the 20 to 40 
marginal teeth inconspicuous or often apparently wanting; basal leaf sheaths 
sloping or rounded, not auriculate, spinulose; male and female flowers on same 
plant; staminate flowers 2-3 mm. long, the anthers 4-celled; pistillate flowers 2-3 
mm. long; mature fruit crowned with 2 or 3 stigmas and usually with 1 or 2 
spiny sterile stigmatic processes; seeds ellipsoid, dull, reticulate with numerous 
4-sided areolae. 

Attached to bottom and floating just below surface of water in ponds, lakes, 
springs, ditches and streams, in fresh or sometimes brackish water, often forming 
large mats, rather common throughout Tex. and Okla., rare in N.M. (Rio Arriba 
Co.) and Ariz. (Santa Cruz and Yavapai cos.), Apr. -Sept.; from Pa. w. to Ore., 
s. to Fla., Tex., N.M., Ariz., Mex., C.A., the W.I., Jam. and Guadeloupe. 

3. Najas flexilis Rostkov. & Schmidt. Slender water-nymph. Fig. 52. 

Plants monoecious; stems freely branched, slender, to 2 m. long; leaves narrowly 
linear, 1-3 cm. long, less than 1 mm. wide tapered from about the middle to a long 
slender point, thin and translucent, very minutely toothed, numerous and crowded 
on the upper parts of the branches, the teeth consisting of protrusions of usually 
1 marginal cell; leaf sheaths with obliquely sloping shoulders, the margins bearing 

126 




Fig. 51: Najas guadalupensis: a, young and mature pistillate flowers, borne singly 
in leaf-sheath axils, X 8; b, mature seed, dull but distinctly reticulate, X 16; c, habit, 
showing plant with threadlike crowded leaves, X %; d, habit, showing plant with less 
crowded leaves, X 1%; e and f, leaf blade, showing marginal and apical teeth, X 6V2', 
g and h, young staminate flowers borne singly in leaf-sheath axils, the anthers still 
enveloped by the spathe, X 8; i, anther (cross section), X 12; j, mature anther at 
anthesis, showing ruptured spathe, X 8. (From Mason, Fig. 36). 




Fig. 52: Najas flexilis: a, mature staminate flower, showing dehisced anther and 
ruptured spathe, X 8; b, young sessile, staminate flower enveloped by spathe, X 8; c, 
pistillate flowers in axil of leaf sheath, showing variations in stigmas, X 8; d, habit, 
plant completely submersed, showing the fascicled leaves, X lVf>; e, mature seed, shiny 
yet finely reticulate under magnification, X 12; f-h, leaf blades, showing minute teeth 
and obliquely sloping somewhat unequally shouldered leaf sheaths, X 5. (From Mason, 
Fig. 35). 



several very minute teeth; intravaginal scales filiform, less than I mm. long; stami- 
nate flowers 2.5-3 mm. long, the anther 1 -celled; pistillate flowers about 3 mm. 
long; stigmas 2 to 4, usually 3; seed narrowly elliptic to lanceolate-ovoid, about 
3 mm. long, apparently smooth and shining but finely reticulate under magnifica- 
tion. 

In fresh to somewhat brackish water, reported by Mason from w. Ariz., May- 
Aug.; n, e. Can, to B. C, s. to Md., Ariz, and Calif.; also Eur. 

The occurrence of this species in our region needs verification. We have seen 
no material. 

Fam. 19. Posidoniaceae Lotsy 

Submerged marine perennials; rhizome and stem densely covered with the per- 
sistent fibrous leaf bases; leaves sheathing at the base, the sheaths open and ligulate; 
blades linear, flat, rounded at the apex, leathery, entire to serrulate; flowers perfect, 
spicate, on long axillary and terminal peduncles; spikes several, subtended by 
reduced leaves; floral bracts absent; perianth absent or of 3 caducous scales; sta- 
mens 3 or 4, hypogynous; anthers extrorse, large, sessile, with a thick connective 
produced beyond the cells, the latter widely separated; pollen threadlike; ovary 
superior, l-ceUed, with a sessile lacerate or muricate stigma; ovule elongated, 
parietal, the micropyle inferior; fruit ovoid, fleshy, indehiscent; seed without endo- 
sperm; embryo with a straight cotyledon. 

A monotypic family, considered to be confined to Australia and the Mediter- 
ranean region. 

1. Posidonia Konig. 

A genus of 2 species. Characters of the family. Sometimes placed in the Naja- 
daceae or Potamogetonaceae. 

1. Posidonia Oceania Konig. Fig. 53. 

Characterized by the rhizome and stem being densely covered with the per- 
sistent fibrous leaf bases; leaves linear, rounded at apex, to 5 dm. long and 7 mm. 
wide, about 13-nerved; inflorescence a 3-flowered spike, 2 flowers of which are 
perfect and one staminate; staminal connective broad, abruptly long-aristate; fruit 
semioval, fleshy, indehiscent. 

This species is included here with some reservations since it is known from 
Texas only by plants being washed up on the beaches along the coast in Cameron, 
Galveston and Nueces counties. Since, however, species in the marine genera 
Cymodocea, Halodule, Thalassia and Halophila are not only frequent in sea drift 
but are also known to grow along the Texas coast, it is quite possible that Posi- 
donia may also eventually be found to grow along the Texas coast. 

Fam. 20. Juncaginaceae Rich. Arrow-weed Family 

Annual or perennial marsh herbs from rhizomes or tubers; leaves basal, linear, 
sheathing, ours with blade terete or semiterete; inflorescence a spikelike raceme 
borne on a naked scape; flowers with short slender or stout pedicels, unisexual 
or perfect, regular to slightly irregular, bractless; bractiform perianthlike appen- 
dages usually 6, in 2 series, each appendage bearing a stamen attached to its base 
or on some the stamen absent; anthers 2-celled, subsessile, opening by slits; pistil 
superior, of 6 or 4 (or 3) connate to weakly united carpels, these sometimes sepa- 
rating in fruit; styles short or absent; stigmas often papillate or plumose; ovule 1 
per carpel, basal, erect; fruit of distinct or weakly united dehiscent or indehiscent 

129 




Fig. 53: Posidonia Oceania: a, habit, X V-y, b, rhizome, X 2; c, inflorescence, enlarged; 
d, flower, enlarged; e, vertical section of flower, enlarged, (a, b, V. F. c-e, from Hut- 
chinson, The Families of Flowering Plants, Vol. 2, Fig. 351). 



carpels, these erect or recurved only at apex, sometimes with hooked spines at 
base. 

About 25 species in 3 genera in temperate and cold regions in both hemispheres, 

1. Triglochin L. 

Herbaceous perennial; leaves broadly sheathing at base, the sheath culminating 
above in an entire or 2-lobed ligule, the blade semiterete; scapes and racemes 
longer than or shorter than the leaves; each perianthlike appendage of the flower 
usually deciduous with its attached stamen and often leaving a conspicuous en- 
larged scar which simulates a reflexed perianth part at the base of the fruit; 
stamens 6 to 3 (or 1), subsessile, the anthers often broader than high, rarely 
much longer than broad; carpels joined to a central carpophore from which only 
the fertile carpels separate at maturity; stigmas of slender papillae; seed linear, 
loosely enclosed in the indehiscent carpel. 

About 15 species, cosmopolitan, especially Austraha and temperate South 
America. 

1. Carpels and stigmas 3; fruit linear-clavate, the axis 3-winged; carpels subulate 
at the base 1. T. palustre. 

1. Carpels and stigmas typically 6, occasionally 3; fruit narrowly oblong-elliptic 

to ovate-prismatic, the axis terete; carpels not subulate at base (2) 
2(1). Rootstock covered with persistent whitish leaf bases; ligules entire or 
essentially so, 1-5 mm. long; leaf blades somewhat obcompressed, 
mostly 1.5-2.5 mm. wide, rarely more; fruits usually 3.5-4.5 mm. 
long and 2-3 mm. thick 2. T. maritimum. 

2. Rootstock usually covered with coarse brownish fibers of the old leaf bases; 

ligules deeply bilobed, 0.5-1 mm. long; leaf blades almost terete, 
1.5 mm. wide or less; fruits usually 3-3.5 mm. long and 1-2 mm. 
thick 3. T. debilis. 

1. Triglochin palustre L. Fig. 28. 

Rootstock short, emitting filiform bulb-bearing stolons; scape to 7 dm. high, 
terminated by an elongate laxly flowered raceme; leaves one half to three fourths 
as long as scape, 1-2 mm. wide, sharp-pointed, the ligule 0.5-1.5 mm. long and 
parted to the base; pedicels slender, erect in fruit and then 4-6 mm. long; perianth 
segments about 1.5 (-2) mm. long, slightly exceeding the stamens; fruit linear- 
clavate, mostly 6-8 mm. long, the 3 carpels separating from below upward and 
remaining suspended from the tip, subulate at base. 

Wet meadows, bogs, mud flats and gravelly stream margins, often brackish or 
alkaline, in N. M. (Otero, Sandoval, San Miguel and Taos cos.), June-Sept.; 
Greenl. and Lab. to Alas., s. to Me., N. Y., 111., la., N. M., Ida. and Calif.; also 
S. A. and Euras. 

2. Triglochin maritimum L. Fig. 54. 

Coarse or slender plant with few to many tufted scapes 1-10 dm. tall from a 
proliferating caudex or stout short rhizome covered with persistent whitish leaf 
bases; leaves thick, 1-8 dm. long, 2-5 mm. wide, the ligule entire and 1-5 
mm. long; scape terminated by a raceme of numerous pedicellate flowers; pedicels 
somewhat ascending to decurrent, 2-6 mm. long; flowers with 6 perianthlike 
appendages each bearing an attached stamen; pistil of 6 (rarely 3) fertile carpels 
rounded at base and united around the slender carpophore; mature fruit ovoid- 
prismatic, 3-4.5 mm. long, 2-3 mm. thick, with carpels united, the edges acutish 
and reflexed, the beaks recurved, indehiscent; seeds linear. Incl. var. elata (Nutt.) 
Gray. 

Saline and alkaline wet meadows and marshes in N.M. (Colfax, Grant, Otero, 
Sandoval, San Juan, Taos and Valencia cos.) and Ariz. (Coconino Co.), May- 
Oct.; Lab. to Alas., s. to Pa., Ind., 111., la., N.M., Calif, and Mex.; also S.A. and 
Euras. 

131 




Fig. 54: Triglochin maritima: a, inflorescence, X %; b, habit, showing racemes 
raised above the leaves, X \'n; c, young flower, showing bractiform perianthlike ap- 
pendages (anthers enclosed) and stigmas of slender papillae, X 8; d, flower, showing 
maturing anthers, each within a perianthlike appendage, and maturing carpels, X 8; e, 
flower, showing the 2 series of perianthlike appendages, each appendage with a dehisced 
anther, the fruit nearly mature, X 8; f, mature fruit, showing the conspicuous appendage 
scars below, X 4; g, fruit (cross section), all carpels fertile, X 6; h, separate mature 
carpel, X 6; i, entire ligule, X 4. (From Mason, Fig. 39). 



3. Triglochin debilis (M.E. Jones) Love & Love. 

Plant slender, 1-3 dm. tall, usually well-spaced and erect-spreading from a 
slender elongate rootstock, the base covered with coarse brownish fibers of the 
leaf bases, the rootstock with conspicuous internodes and bracteate nodes; leaves 
8-20 cm. long, the sheaths membranous-margined, terminating above in a 2-lobed 
ligule 0.5-1 mm. long; scapes longer than the leaves, terminated by a strict 
raceme, the rachis may be either straight or fractiflex; pedicels slender; flower 
with 6 perianthlike appendages each bearing an attached anther; mature fruit 
composed of 6 united carpels about 3-3.5 mm. long and 1-2 mm. thick, usually 
all fertile; fruiting carpels separating readily from the slender carpophore, inde- 
hiscent; seeds slender, needlelike. T. concinnum Davy var. debilis (M.E. Jones) 
J. T. Howell. 

In wet meadows and marshes along streams, in brackish to saline or alkaline 
situations, in Ariz. (Coconino and Navajo cos.), May-Oct.; from Ore. to Calif., 
e. to and beyond the Rocky Mts., from N. D. to Colo, and Ariz. 

Fam. 21. Alismataceae Vent. Water Plantain Family 

Annual or perennial lacticiferous aquatic or marsh plants with fibrous roots 
from a usually somewhat thickened rootstock and a cluster of basal leaves with 
their long petioles sheathing a scape; leaves at first typically bladeless but soon 
developing either a linear or sagittate type of blade with prominent nerves and 
transverse veinlets; scape erect or arching, with a simple or branched bracteate 
inflorescence; flowers perfect or unisexual, regular, borne in verticils; perianth 
segments imbricate or involute in bud; sepals 3, green, persistent; petals 3, decidu- 
ous; stamens 6 to many, included, the filaments distinct, the anthers 2-celled and 
dehiscing by longitudinal slits; carpels numerous, distinct, 1-celled and mostly 
1-ovuled, arranged in a ring or crowded on a receptable to produce a headlike 
fruit of flat or turgid achenes that are usually provided with resin ducts and/ or 
wings. 

A family of about 13 genera and 90 species of worldwide distribution. 

Species that comprise this family are known to attract marsh and song birds 
and to provide shade and shelter for young fish, while the tubers formed by many 
species, as well as the achenes, are eaten by wildfowl. Mammals, such as muskrats, 
beavers and porcupines, are known to eat the vegetative parts of many species of 
Sagittaria. 

Seeds of most of our species are ideafly suited for dissemination by birds and 
animals in that the beak formed by the style can readily become hooked in 
feathers and furs, and even to minute particles of soil that may remain on muddy 
feet. Also, the resin ducts and suberous wings and excrescences of the achenes 
of many species enable them to float great distances. 

1. Achenes arranged in a single ring on the receptacle, strongly flattened; 
stamens 6 1. Alisma 

1. Achenes densely crowded over the surface of the receptacle; stamens more 

than 6 (2) 

2(1). Flowers all perfect; achenes plump; fruiting heads simulating a bur 

2. Echinodorus 

2. Flowers perfect or unisexual, the upper ones mostly staminate; achenes flat- 

tened; fruiting heads not burlike 3. Sagittaria 

|Lu ( LIBRARY i'-^l 

12= 



L IBRARY j 



c-\ 






Z-;:^/ 133 




Fig. 55: a-e, AUsma triviale: a, habit, about X M^; b, flower, X 5; c, fruit head, 
X 5; d, seed, side view, X 5; e, seed, dorsal view, X 5. f, AUsma graniineum: f, seed, 
dorsal view, X 5. (V.F.). 



1. Alisma L. Water Plantain. Mud Plantain 

Aquatic herbs, perennial or sometimes behaving as annuals, emersed or grow- 
ing on wet mud, rarely submersed, from an apically flattened corm and fibrous 
roots; leaves basal, erect or rarely floating, with lanceolate or oblong-ovate to 
broadly ovate blades, rarely reduced to ribbonlike phyllodes; inflorescence a large 
open panicle; flowers small, 3-10 mm. broad, perfect, numerous, on 3-bracteate 
pedicels unequal in length; sepals 3, green, persistent; petals 3, white or occa- 
sionally rose or pink; stamens 6 to 9; pistils separate, arranged in a more or less 
3-sided whorl on the receptacle; fruit an achene, with 1 or 2 grooves to almost 
plane on the back. 

About 10 species mostly in the North Temperate Zone. 

1. Achenes about as wide as long, distinctly bisulcate on the back with the 
median rib typically broad and rounded; pedicels stout; petioles 
4-6 mm. wide; leaf blade elliptic-lanceolate to narrowly lanceolate, 
to about 2.5 cm. wide 1. A. gramineum. 

1. Achenes longer than wide, with a solitary groove to almost plane on the back; 

pedicels slender; petioles less than 4 mm. wide; leaf blade typically 
broadly elliptic and usually much more than 2.5 cm. wide (2) 

2(1). Achenes 2 mm. long or less, the dorsal groove shallow or with a somewhat 
depressed slight thickening in the trough; fruiting heads 3.5 mm. or 

less in diameter; distribution in Oklahoma and Texas 

2. A. subcordatum. 

2. Achenes more than 2 mm. long, the dorsal groove deep; fruiting heads more 

than 3.5 mm. in diameter; distribution in New Mexico and Arizona 
3. A. triviale. 

1. Alisma gramineum Gmel. Fig. 55. 

Submersed or amphibious perennial herb 5-20 cm. high, erect or ascending or 
(when plant submersed) leaves and stems floating; leaves usually erect, with 
long broad petioles (4-6 mm. wide) and linear-lanceolate to lanceolate blades 
(these rarely absent), to about 2.5 cm. wide; inflorescence a scapose verticillate 
panicle to 2 dm. long, sometimes shorter than the leaves; branchlets and pedicels 
subtended by 2 or 3 lanceolate papery bracts; pedicels stout, often recurved in 
fruit; flowers 5-7 mm. broad; sepals green, persistent; petals usually white, 
rhombic, entire to somewhat ^erose; stamens 6 to 9; pistils in an obscurely 3-sided 
whorl; fruiting heads 3-4 mm. in diameter; achenes often orbicular to orbicular- 
cuneate in outline, about 2.5 mm. in diameter, the beak on the inner margin, 
distinctly bisulcate on the back with the median rib broad and rounded. A. Geyeri 
Torr., A. gramineum var. Geyeri (Torr.) Samuelsson. 

On mud and in shallow water of lakes in N.M. (Rio Arriba and Sandoval cos.) 
and Ariz (Coconino Co.), June-Sept.; from Calif., Ariz, and N.M., n. to Wash, 
and e. to Minn. 

Our material is usually referred to var. angustissimum (DC.) Hendricks. 

2. Alisma subcordatum Raf. 

Erect perennial herb with a basal cluster of erect long-petioled laminated leaves 
surrounding a scape, essentially glabrous; leaf blades ovate to elliptic, cuneate to 
cordate at base, abruptly acute at apex, to 12 cm. long and 8 cm. wide, usually 
shorter than the petioles; scape to 6 dm. tall, with whorled panicled branches of 
small white or pinkish flowers; bracts lanceolate, acuminate, about 1 cm. long; 
pedicels filiform; flowers perfect, numerous; sepals broadly ovate to suborbicular, 
obtuse, to 2.5 mm. long; petals to 2.5 mm. long; anthers spherical, 0.3-0.5 mm. 
long; ovaries many in a simple circle on a small flattened receptacle; style 0.2-0.4 
mm. long, about one fourth as long as ovaries; fruiting heads 3.5 mm. or less in 

135 







Fig. 56: Echinodorus parvulus: a, habit, X I; b, bud, X 6; c, flower, X 9; d, achene, 
X 40; e, seed, X 30. (Courtesy of R. K. Godfrey). 



diameter; achenes obliquely obovate, 1.5-2 mm. long, the solitary dorsal groove 
shallow or with a somewhat depressed slight thickening in the trough, the minute 
beak ascending. A. parviflorum Pursh, A. Plantago-aquatica var. parviflorum 
(Pursh) Far\\'. 

Usually in shallow water of marshes, streams and ponds in Okla. (Delaware, 
McCurtain, Mayes, Johnston, Murry and Craig cos.), n.e. Tex. (Bowie Co.) and 
the Tex. Panhandle (Hemphill Co.), June-Sept.; Ont., N. E. and N. Y., w. to 
Minn, and Neb., s. to Fla. and Tex. 

Though reported from Arizona, we have seen no material of this species from 
the state. 

3. Alisma triviale Pursh. Fig. 55. 

Erect perennial to 12 dm. tall; leaves usually long-petioled, linear-lanceolate to 
broadly elliptic, 5-20 cm. long, cuneate to truncate or subcordate at base, sub- 
obtuse to abruptly acute at apex; inflorescence on an erect scape with several 
whorls of branches, each with 1 or more whorls of flowers or further compounded 
into verticillate branches much longer than the leaves, each branch and each 
pedicel subtended by 2 or 3 lanceolate papery bracts; flowers hypogynous; sepals 
3, plane or somewhat gibbous, obtuse, green, 3-4 mm. long; petals 3, white or 
sometimes rose to pink, 3-6 mm. long, rhombic in outline, margins entire or 
minutely erose; stamens 6 to 9, much-surpassing the ovary; filaments glabrous; 
anthers 0.6-1 mm. long; pistils numerous, in a single often obscurely 3-sided 
whorl; styles 1-1.5 mm. long, as long as or longer than ovary; fruiting heads 
more than 3.5 mm. in diameter; achenes with a solitary deep groove on back, 
2-3 mm. long, 1.5-2 mm. wide, the beak on the inner angle, erect or suberect. 
A. brevipes Greene, A. Plantago-aquatica subsp. brevipes (Greene) Samuelsson, 
and var. americanum Schult. & Schult., and var. Michaletii (Asch. & Grabn.) 
Buch. 

In shallow water or on wet mud in N.M. (Rio Arriba, Valencia and Taos cos.) 
and Ariz. (Coconino, Navajo and Cochise cos.), May-Sept.; Que. to B.C., s. to 
Md., W.Va., Mich., la., Neb., N.M., Ariz, and n. Mex. 

2. Echinodonis Rich. Burhead 

Annuals or short-lived perennials of wet habitats, with basal leaves and naked 
erect or repent scapes that are sparingly branched or occasionally simple; flowers 
pedicellate, perfect, usually in remote whorls; sepals 3, persistent; petals 3, im- 
bricated in the bud, white, deciduous; stamens 6 to usually many more; filaments 
elongate, usually exceeding the anthers in length; achenes forming a head, turgid, 
ribbed or ridged, beaked or beakless. 

A dozen or more species in America, Europe and Africa. 

1. Achenes 20 or fewer in a loose head, essentially beakless; stamens 9; anthers 
basifixed 1. E. parvulus. 

1. Achenes 30 or more in a dense tight head, prominently beaked; stamens 12 or 

more; anthers versatile (2) 

2(1). Sepals with papillose ridges; scape erect when young but soon repent; 
achenes with summit or keel often crested and the beak ascending; 
pellucid lines of leaves mostly 1 mm. or more apart and rarely 
exceeding 1 mm. in length 3. E. cordifolius. 

2. Sepals with smooth veins; scape rigidly erect at maturity; achenes with keel 

entire and the beak erect or nearly so; pellucid lines of leaves 
mostly less than 1 mm. apart and often several mm. long (3) 

3(2). Plants robust, usually much more than 2 dm. tall; leaves typically broadly 
ovate, broadly cuneate to cordate at base; beak of achenes 1.2-2 
mm. long 2. E. rostratus. 

137 




Fig. 57: Echinodorus rostratus: a, mature achene, X 8, b, upper part of inflores- 
cence, showing maturing burlike fruits, X %; c, whorl of flowers, X %; d, flower, 
showing the arrangement of the 12 stamens, X 11/l>; e, stamen, X 8; f, habit of mature 
plant, X %; g, habit of young submersed plant, showing transition stages from early 
linear to mature cordate leaf blades, X %. (From Mason, Fig. 46). 






Fig. 58: Echinodorus rostratus: a, head, X 5; b, achene, X 25; c, seed, X 60. 
(Courtesy of R. K. Godfrey). 



3. Plants delicate, rarely more than 2 dm. tall; leaves typically lanceolate, nar- 
rowly cuneate to somewhat rounded at base; beak of achenes 0.5-1 
mm. long 2. E. rostratus var. lanceolatus. 

1. Echinodorus parvulus Engelm. Fig. 56. 

Plants small and delicate, with the shoots often creeping and proliferous; scapes 
to 1 dm. tall, supporting a single umbellate inflorescence of 2 or more flowers; 
leaves with a petiole to 5 cm. long, the blade (to 3 cm. long and 8 mm. wide) 
narrowly elliptic and acutely tapered at both ends; pedicels slender, to 3 cm. long, 
reflexed in fruit; flowers white, about 6 mm. across; achenes 8-ribbed, reddish- 
brown, glandless. E. tenellus var. parvulus (Engelm.) Fassett, Helianthium par- 
vulum (Engelm.) Small. 

Among grasses in wet sandy soils about ponds in s. Tex., Mar.-Sept.; from Fla. 
and Tex., locally n. to Mass., 111. and Mo. 

2. Echinodorus rostratus (Nutt.) Engelm. Figs. 57 and 58. 

Plants usually coarse; scapes rigidly erect, to 6 dm. tall, exceeding the leaves; 
leaves broadly ovate, cordate to broadly rounded-cuneate at base, obtuse at apex, 
to 15 cm. long and often as broad; umbels proliferous, in a branched panicle; 
flowers white, about 1 cm. across; achenes with 2 glands at base of the conspicu- 
ous erect beak; seeds brown, obliquely oval, with rows of murications. E. cordi- 
folius, misapplied; E. Berteroi (Spreng.) Fassett, as to descr. 

In mud and shallow water about lakes, ponds and along streams mostly in s. 
Tex. but sparingly throughout most of the state, in Okla. (Alfalfa and Kay cos.) 
and apparently isolated in Yuma Co., Ariz., May-Oct.; from Ont., w. to Calif, 
and s. to Fla., Tex. and Mex. 



139 




Fig. 59: Echinodorus cordif alius: a, habit, X Va; b, flower, X 1%. 




Fig. 60: Echinodorus cordifolius: 
X 18; e, seed, X 33. (Courtesy of R, 



a, habit, X %; c, head of achenes, X 5; d, achene, 
K. Godfrey). 



Var. lanceolatus Engelm. Plants small and delicate, with typically lanceolate 
leaves. Echinodorous Berteroi var. lanceolatus (Engelm.) Fassett, as to descr. 
Habitat and distribution similar to that of var. rostratus. 

In deeper water the plants rarely produce normal adult foliage leaves and never 
flower, but develop large, ribbonlike submersed leaves. 

3. Echinodorus cordifolius (L.) Griseb. Figs. 59 and 60. 

Plants coarse and usually stout; scapes prostrate, arching and creeping, to 12 
dm. long, proliferous and bearing numerous whorls of flowers, also sometimes pro- 
ducing leaves with the flowers; leaves with a petiole to 2 dm. or more long, the 
blade (to 2 dm. long and nearly as broad) broadly ovate and truncately cordate at 
base and obtuse at apex; flowers white, 12 mm. or more across; achenes with the 
keeled back denticulate. E. radicans (Nutt.) Engelm. 

In mud and shallow water of ponds and quiet streams of e. Tex. and e. Okla. 
(LeFlore and Muskogee cos.), Apr.-June; from s.e. Va., 111., Mo. and Kan., s. 
to Fla., Tex. and Mex. 

3. Sagittaria L. Arrowhead 

Paludal or aquatic mostly perennial erect or lax stoloniferous herbs, with milky 
juice, monoecious or rarely dioecious, sometimes tuber-bearing; leaves submersed 
or emersed, with long cellular petioles, bladeless (i.e., phyllodia) or with unlobed 
or sagittate blades; scapes erect or laxly ascending, sheathed at base by the bases 
of the leaf petioles, supporting a narrow verticillate inflorescence that is simple or 
sparingly branched; flowers produced all summer, pedicellate, in whorls of three, 
mostly unisexual, subtended by membranous bracts, the staminate flowers typically 
uppermost in the inflorescence; sepals 3, persistent, in fruit appressed, loosely 
spreading or reflexed; petals 3, white or rarely pink, imbricated in the bud, usually 
exceeding the sepals, deciduous; stamens whorled, mostly numerous; carpels 
numerous, spirally arranged in a crowded spherical head on a dome-shaped re- 
ceptacle, 1-ceUed and 1-ovuled; achenes flattened, membranous-winged, more or 
less beaked. 

About 20 species, mostly in America. 

1. PistiHate flowers (in fruit) with sepals appressed or spreading and pedicels 
recurved and noticeably thickened 1. S. montevidensis. 

1. Pistillate flowers (in fruit) with reflexed sepals and pedicels ascending or (if 

recurved) not noticeably thickened (2) 

2(1). Filaments pubescent or minutely scaly (3) 

2. Filaments smooth (5) 

3(2). Bracts of inflorescence thinly membranous, smooth, more or less connate; 
filaments dilated (4) 

3. Bracts of inflorescence somewhat thickened, papillose or coarsely ridged, 

nearly free; filaments linear 4. S. lancifolia. 

4(3). Pistillate pedicels ascending, if recurved the achene beak less than 0.3 mm. 
long; leaves typically narrow 2. S. graminea. 

4. Pistillate pedicels recurved; subulate beak of mature achenes 0.3 mm. or more 

long; leaves typically broad 3. S. platyphylla. 

5(2). Bracts of inflorescence papillose; leaves never sagittate (6) 

5. Bracts of inflorescence smooth or at most pubescent; leaves sagittate (7) 

6(5). Bracts densely papillose, 7 mm. long or less, obtuse; achenes 1.5 mm. long 
or less; Texas in our area 5. S papillosa. 

6. Bracts sparsely papillose, longer, attenuate; achenes larger; Oklahoma in our 

area 6. S. ambigua. 

142 



A 




Fig. 61: Sagittaria montevidensis: a, habit, X 1/3; b, leaf, X %; c, flower, X 1^/2, d, 
fruit, X 1/3; e, achene, X 5. (V. F.). 




Fig. 62: a-d, Sagittaria graminea: a, habit, X %; b, fruit, X 2%; c, anther, X 5; d, 
achene, X 5. e-i, Sagittaria lancifolia: e, leaf, X y-y, f, bracts, X 21/0; g, flower, X ly-z', 
h, anther, X 5; i, achene, X 5. (V. F.). 



7(5). Achene beak laterally inserted, more or less projecting horizontally (8) 

7. Achene beak apically inserted, more or less erect (10) 

8(7). Bracts of inflorescence cymbiform, obtuse to acute, rather firm, sometimes 
pubescent; achene beak 0.5 mm. long or more 7. S. ladfolia. 

8. Bracts of inflorescence almost plane, at least not cymbiform, acuminate to 

attenuate, membranous, never pubescent; achene beak Jess than 0.5 
mm. long (9) 

9(8). Achenes without or with solitary facial wings; leaf blades not more than 
2.5 dm. long, the terminal lobe linear to lanceolate, usually long- 
acuminate, commony less than half as long as the basal lobes; 
scape usually simple 8. S. longiloba. 

9. Achenes with facial wings and tuberculations; leaf blades typically 2-4 dm. 

long, the terminal lobe ovate to broadly lanceolate, acute to short- 
acuminate, more than half as long as the basal lobes; scape some- 
times branched 9. S. Greggii. 

10(7). Achene usually with one narrow facial wing or keel, the beak somewhat 
curved and 0.5 mm. or more long 10. S. brevirostra. 

10. Achene face wingless, typically with a large resin duct, the minute to obso- 

lescent beak erect 11. S. cuneata. 

1. Sagittaria montevidensis Cham. & Schlecht. Fig. 61. 

Emersed aquatic annual, only the early stages completely submersed, erect, to 
5 dm. tall; leaves erect-spreading, usually with stout spongy petioles; leaf blades 
broadly ovate, sagittate, to 2 dm. or more long and wide; scape erect or reflexed, 
simple or occasionally branched below, with up to 10 whorls; bracts membranous, 
ovate to ovate-lanceolate, acute to attenuate, connate, about 1 cm, long; pistillate 
flowers usually with a ring of functional stamens; sepals orbicular-ovate, concave, 
about 13 mm. long, covering most of the fruiting head; stamens with linear 
pubescent filaments; heads of carpels to 2 cm. in diameter; achenes cuneate- 
obovate, to 2.5 mm. long and 1.3 mm. wide, the faces usually with a resin duct, 
the horizontal or oblique beak about as long as the breadth of the achene and 
narrowly winged on the margin. 5. calycina Engelm., Lophotocarpus calycinus 
(Engelm.) J. G. Sm. 

Sloughs, lakes and ponds in e., cen. and w. Tex., Okla. (Adair, Sequoyah, 
Cherokee, Murray and Johnston cos.) and N.M., June-Oct.; O. and Mich., w. 
to N.D., Calif, and N.M., s. to Va., Tenn., La. and Tex. 

Our plants have been segregated as subsp. calycina (Engelm.) Bogin. 

2. Sagittaria graminea Michx. Fig. 62. 

Leaves erect, either represented by thin broadly linear (strap-shaped) acute to 
shortly acuminate phyllodia or with the slender petioles bladeless or with nar- 
rowly lanceolate tapering blades to 2 dm. long and 25 mm. wide; scape simple, 
usually surpassed by the leaves, with as many as 10 whorls, the flowers with fili- 
form ascending or spreading pedicels to 3 cm. long, the lower one or two whorls 
of pistillate flowers or sometimes all staminate; bracts ovate, obtuse to subacute, 
to 6 mm. long, more or less connate, membranous; sepals ovate, obtuse, to 5 mm. 
long; petals white or rarely pinkish, to 6 mm. long; stamens with dilated pubescent 
filaments to 1 mm. long; fruiting heads to 1 cm. in diameter; achenes obovate, to 
2 mm. long and 1.2 mm. wide, the narrow-winged back strongly rounded to a 
high shoulder, the sides plane or with 1 or 2 narrow ridges, the subulate beak to 
0.3 mm. long, obliquely inserted below the summit of the achene. S. cycloptera 
(J. G. Sm.) Mohr. 

Rooted in mud or in shallow water of ditches, ponds, marshes and streams in 
e. and s.-cen. Tex. and Okla. (Osage Co.) to s.e. Ariz., flowering throughout 
the year but mostly Apr.-Nov.; throughout e. N. A., w. to the Great Plains; also 
Cuba. 

145 




Fig. 63: Sagittaria papillosa: a, habit, X 14; b, staminate flower (young), X 2% c, 
staminate flower, X 21/2; d, stamen (two views), X 5; e, pistillate flower, X IV-y, f, 
fruiting head, X 2V2; g, achene, X 6. (V.F.). 



3. Sagittaria platyphylla (Engelm.) J. G. Sm. 

Leaves erect, overtopping the scape; leaf blades ovate to elliptic or lanceolate, 
unlobed, to 18 cm. long and 8 cm. wide; scape simple, with as many as 8 whorls, 
the 1 to 4 lower whorls pistillate and with their thickish pedicels to 25 mm. long 
and soon recurving; bracts ovate, obtuse, scarious, strongly connate, to 8 mm. 
long; stamens with dilated pubescent filaments that are mostly longer than the 
anthers; fruiting heads to 15 mm. in diameter; achenes cuneate-obovate, to 2 mm. 
long and 1.2 mm. wide, the dorsal keel rounded to the subtruncate summit, the 
faces with 1 to 3 narrow ridges; beak subulate, 0.3 mm. or more long, obliquely 
ascending. S. graminea var. platyphylla (Engelm.) J. G. Sm. 

In mud or shallow water of marshes, streams, sloughs, swamps and ponds in 
e. Tex. and Okla. (Atoka, Murray, Pushmataha, Choctaw, Latimer and Mc-Cur- 
tain COS.), Apr.-Oct.; Mo. w. to Kan., s. to Tex. and Ala.; adv. in the Pan. Canal 
Zone. 

4. Sagittaria lancifolia L. Fig. 62. 

Leaves erect; leaf blades ovate to elliptic or narrowly lanceolate, unlobed, taper- 
ing to both ends, firm, to 4 dm. long and 1 dm. wide; scapes simple or branching 
at lower nodes, the main axis with as many as 10 whorls, the lower 1 to 4 whorls 
pistillate with pedicels to 25 mm. long, the staminate pedicels to 35 mm. long; 
bracts ovate, obtuse, strongly papillose, to 15 mm. long, connate; sepals more or 
less papillose; stamens with slender arachnoid filaments that are longer than the 
anthers; fruiting heads about 15 mm. in diameter; achenes cuneate-oblanceolate, 
falcate, to 2.5 mm. long and 1 mm. wide, dorsally narrowly winged, usually with 
1 or 2 low facial ridges; beak obliquely inserted, subulate from a thick base, to 
0.8 mm. long, ascending. S. falcata Pursh. 

In fresh-water and brackish tidal marshes, swamps, and along streams in s.e. 
Tex. and Okla., May-Nov.; Fla. to Tex., n. to Del.; also Mex. and C.A. 

Our plants, as described here, have been segregated as subsp. media (Mich.) 
Bogin. 

5. Sagittaria papillosa Buch. Fig. 63. 

Leaves erect; leaf blades linear to narrowly lanceolate, to 25 cm. long and 5 cm. 
wide; scapes typically branching from the lowest whorl, the main axis with as 
many as 10 whorls, the lower 1 to 4 whorls pistillate with pedicels much shorter 
that those of the staminate; bracts ovate, obtuse, somewhat connate, densely 
papillose, to 1 cm. long; sepals to 6 mm. long, more or less papillose; petals about 
twice as long as the sepals; stamens with linear glabrous filaments to 1.6 mm. long; 
fruiting heads about 1 cm. in diameter; achenes cuneate, to 1.5 mm. long and 
1 mm. wide, with the remotely crested dorsal wing about 0.2 mm. wide and the 
ventral wing somewhat narrower, the faces plane; beak broad-based, laterally 
inserted above the middle of the achene body, more or less recurving, about 0.2 
mm, long. 

In swamps, marshes, bogs, ditches, small ponds and depressions in prairies in 
e. and s. Tex. and e. Okla. (McCurtain Co.), Mar.-Nov.; Ark., La., Okla. and 
Tex. 

6. Sagittaria ambigua J. G. Sm. 

Plant erect; leaves lanceolate to ovate, 12-20 cm. long, 4-10 cm. wide, the 
petioles to 35 cm. long; scape erect, 3-9 dm. tall, with 2 to 10 whorls of flowers; 
pistillate pedicels 15-35 mm. long, longer than the staminate pedicels; bracts 
linear to lanceolate, acuminate, slightly papillose, mostly 1-3 cm. long, nearly 
free; pedicels ascending, 1-2.5 cm. long; sepals oblong, 5-7 mm. long, remotely 
papillose; petals ovate, 8-10 mm. long; filaments slender, glabrous; fruiting heads 
1-1.5 cm. in diameter; achenes cuneate-obovate, 1.5-2 mm. long, 0.8-1.4 mm. 
broad, narrowly thin-winged, the faces smooth or with a longitudinal thin keel; 

147 




Fig. 64: Sagittaria latifolia: a, stamen, showing glabrous filament which is longer 
than anther, X 8; b, inflorescence, showing whorls of staminate flowers and of pistillate 
flowers, the sepals reflexed, X %; c, habit, showing rhizomes and branched inflorescence, 
X %; d-f, mature achenes, the margins with broad corky and laterally disposed wings, 
X 6; g, part of inflorescence, showing whorls of mature fruits, X %; h, corm at the 
end of rhizome, X %. (From Mason, Fig. 51). 




Fig. 65: Sagittaria latifoUa: variation in leaf blades, a, c-f, S. latifolia: e, early sea- 
sonal phase, and f, late seasonal phase of same plant; b, 5. latifolia var. obtusa. All 
X %. (From Mason, Fig. 52). 



beak minute, 0.1-0.2 mm. long, horizontal or incurved. 
Swamps and lake shores, Okla.; s.w. Mo., Kan. and Okla. 

7. Sagittaria latifolia Willd. Wapato, Duck-Potato. Figs. 64 and 65. 

Leaves erect or erect-spreading; leaf blades triangular-ovate, obtuse to acute at 
apex, sagittate, the portion above the basal lobes to 25 cm. long and wide, the 
linear to ovate-triangular basal lobes one half as long as or longer than the body 
of the blade; scapes angled, occasionally branching from the lowest whorls, the 
main axis with as many as 10 whorls, with one or more of the lower whorls 
pistillate or all unisexual; pedicels of pistillate flowers typically shorter than those 
of the staminate flowers; sepals to 1 cm. long, glabrous to densely pubescent; 
bracts cymbiform, distinctly or only slightly connate, thin, somewhat scarious, 
obtuse to acute, glabrous to densely pubescent; stamens with slender filaments that 
are usually longer than the anthers; fruiting heads to 25 mm. in diameter; achenes 
obovate, to 3.5 mm. long and 3 mm. wide, with broad marginal wings but no 
facial keels; beak broad-based, subhorizontal to slightly incurved, to 2 mm. long. 
Incl. var. obtusa (Muhl.) Wieg. 

In water or wet places from s.e. to n. Tex. and Okla. (Washita, Logan, Ottawa, 
Delaware, Woodward, Adair and Choctaw cos.), w. through N.M. (Sandoval Co.) 
to Ariz. (Navajo Co.), May-Sept.; throughout most of the U. S. and much of 
Latin Am. 

Both the entirely glabrous widespread var. latifolia and the southern var. 
pubescens (Muhl.) J. G. Sm. (5. pubescens Muhl.), with densely pubescent bracts 
and calyx, are rare in our area. Several variants, such as f. hastata (Pursh) 
Robins, and var. obtusa (Muhl.) Wieg., have been proposed, based on leaf 
variations. 

8. Sagittaria longiloba Engelm. ex Torr. in J. G. Sm. Flecha de agua. Fig. 66. 
Leaves erect or erect-spreading; leaf blades ovate-triangular, acute at apex, 

sagittate, the portion above the basal lobes to 15 cm. long and 1 dm. wide, the 
conspicuously long linear to lanceolate basal lobes always longer than and 
commonly twice as long as the body of the blade; scapes commonly branching at 
the lowest whorl, the main axis with as many as 12 whorls; pedicels to 35 mm. 
long, ascending; bracts ovate-lanceolate to narrowly lanceolate, attenuate, to 
25 mm. long, connate at base; stamens with glabrous linear filaments to 3 mm. 
long and exceeding the anthers; fruiting heads to 12 mm. in diameter; achenes 
obovate, to 2.3 mm. long and 1.3 mm. wide, the narrow dorsal wing to 0.3 mm. 
wide, the ventral wing nearly obsolete, the faces commonly 1 -winged; beak 
laterally inserted, triangular, to 0.15 mm. long or obsolete. 

In shallow water of sloughs, ditches, ponds and swamps, especially common 
in roadside ditches in s. Tex. and extending to n. and w. Tex., Okla., N. M. and 
Ariz., Apr.-Nov.; Ariz., N. M., Calif.(?), Colo., Kan., Neb., Okla., Tex., and Mex. 

9. Sagittaria Greggii J. G. Sm. Fig. 67. 

Erect aquatic of shallow water, to 1 m. tall; tip of ephemeral rhizome at length 
becoming a globose perennial corm, or plant behaving as an annual; leaves 
erect, the blades sagittate, 2-4 dm. long, the basal lobes 2 to 3 times as long 
as the terminal, linear to linear-lanceolate, sometimes acuminate, the submersed 
juvenile leaves with blades entire or lacking; inflorescence simple or branched, 
subequal to or longer than leaves; lower flowers pistillate, upper ones staminate, 
occasionally a. few flowers perfect; pistillate flowers on slender ascending often 
unequal pedicels, the pedicels 1-3 cm. long; sepals becoming reflexed, not growing 
with fruit; petals white, blades orbicular, claws cuneate; rudimentary stamens in 
a single whorl, sometimes a few with pollen; staminate flowers withering-persistent, 
rarely with rudimentary pistils; stamens numerous, the filaments longer than 

150 




Fig. 66: Sagittaria longiloba: a, habit, X %; b, single leaf, X i/^; c, flower, X 2%; 
d, stamens, X 5; e, fruit, X %; f, achene, X 5. (V. F.). 




Fig. 67: Sagittaria Greggii: a, scape (cross section), X IVo; b. whorls of maturing 
fruits, showing the reflexed sepals and long bracts subtending the pedicels, X %; c, 
habit, showing narrowly sagittate leaf blades, X Vr,; d, leaf base sheath, X %; e, stamen, 
showing glabrous filament with dilated base, X 8; f, tip of inflorescence, showing whorls 
of staminate flowers and pistillate flowers below beginning to mature, X %; g and h, 
leaf blade variations, X %; i. mature achene, showing the tubercled irregularly thickened 
lateral ribs, X 8. (From Mason, Fig. 49). 



anthers, glabrous, somewhat dilated at base; fruiting heads depressed-globose; 
achenes obovate, 2-3 mm. long, winged, the lateral ribs irregularly thickened and 
winged or tubercled, curved to orbicular in outline, the style beak short and erect, 
occasionally pushed in a lateral direction as the achene matures. 

In shallow water of irrigation ditches and rice fields in Ariz, and N. M., 
Apr.-Nov.; also Calif, and n. Mex. 

Closely related to S. longiloba, with which it apparently intergrades, or more 
likely, with which it is probably conspecific. We are in agreement with Mason, 
however, who chose to maintain these two concepts until further field studies 
can be made. 

10. Sagsttaria brevirostra Mack. & Bush. Fig. 68. 

Leaves erect; leaf blades broadly ovate to lanceolate, obtuse to acute at 
apex, sagittate, the portion above the basal lobes to 2 dm. long and usually 
about as wide, the ovate to ovate-lanceolate and acute basal lobes about equaling 
the body of the blade; scapes simple or branched at base, the main axis with 
as many as 12 whorls, the lower 2 to 6 whorls pistillate with pedicels to 2 cm. 
long, the staminate with slightly longer pedicels; bracts firm, lanceolate, long- 
attenuate, to 25 mm. long; stamens with slender glabrous filaments about as 
long as the anthers; fruiting heads depressed, not noticeably echinate, to 2 cm. 
in diameter; achenes cuneate-obovate to quadrate, to 3 mm. long and 2 mm. 
wide, with an often dentate or serrate dorsal keel and usually with a narrow 
facial ridge; beak broad-based, obliquely ascending, to 1.5 mm. long, terminating 
the straight ventral margin. S. Engelmanniana J. G. Sm. subsp. brevirostra (Mack. 
& Bush) Bogin. 

Along rivers, ditches and sloughs in cen. Tex. to Okla. and n. N. M. (Taos 
Co.), June-Aug.; O and Mich., w. to S.D. and s. to Tex. and N. M. 

11. Sagittaria cuneata Sheld. Fig. 69. 

Leaves erect or erect-spreading; leaf blades broadly ovate to ovate-triangular, 
obtuse to acute at apex, sagittate, the portion above the basal lobes to 15 cm. 
long and 1 dm. wide, the deltoid basal lobes somewhat smaller than the body 
of the blade; scapes erect or arching, simple or sometimes branched, the main 
axis with as many as 7 whorls, the lower 1 or 2 (or sometimes all) whorls 
pistillate and subsessile or on pedicels to 2 cm. long, the staminate pedicels 
somewhat longer; bracts narrowly ovate to lanceolate, acute to attenuate, usually 
connate at base, to 2 cm. long; stamens with glabrous subulate filaments that 
about equal the anthers; fruiting heads to 15 mm. in diameter; achenes obovate, 
to 2.5 mm. long and 2 mm. wide, the wide dorsal keel rounded, the faces usually 
with a low narrow ridge; beak subulate, usually recurved, erect to suberect, 
to 0.4 mm. long, terminating the strongly rounded ventral keel. S. arifolia Nutt. 
ex J. G. Sm. 

Along rivers and streams in the Tex. High Plains, Okla., N.M. and Ariz., 
June-Sept.; n.e. Can., s. to N.E., N.Y., O., Ind., 111., la., Kan., Tex., N.M., 
Ariz, and Calif. 

Fam. 22. Butomaceae Rich. Flowering-rush Family 

Perennial aquatic or marsh herbs with stout short or elongate rhizomes and 
usually with milky juice; leaves cauline or basal; flowers perfect in involucrate 
umbels or solitary; sepals 3, persistent; petals 3, showy; stamens 6 to many, 
free, the outer ones usually sterile; anthers basifixed, 2-celled, laterally dehiscent; 
pistils 4 to 8, free or basally coherent, with numerous ovules attached over the 
inner surface; fruit a many-seeded follicle, dehiscing on the inner side; seeds 
without endosperm. 

153 




Fig. 68: Sagittaria hrevirostra: a, habit, X Vw b, leaf, X V-r, c, flower, X ly^', d, 
calyx, X V,-,; e, stamen, X 5; f, fruit, X \'2\ g, achene, X 5. (V. F.). 




Fig. 69: Sagittaria cuneata: a, stamen, showing short glabrous filament, X 6; b, 
whorls of maturing fruits, X %; c, staminate flower, X %; d, habit, showing rhizomes, 
inflorescence and the somewhat spreading leaves, X %; e, pistillate flower, X %; f, 
papillate stigma, X 40; g, ovary terminating in stout style with papillate stigma, X 8; 
h, mature achene, showing wings and the erect beaklike persistent style, X 6; i-o, leaf 
blade variations (note that the basal lobes are generally shorter than terminal lobe), 
X %. (From Mason, Fig. 50). 



Several genera containing about 10 species, mostly of warm regions. 

1. Hydrocleys Rich. 

Characteristics of family. Four species, all native to Brazil. 

1. Hydrocleys nymphoides (Willd.) Buch. Water-poppy. Fig. 70. 

Rhizomes rooting at the nodes; leaves alternate, long-petioled; leaf blades 
broadly ovate, cordate at base, rounded at apex, 5 cm. long or more, entire, glossy 
on upper surface, somewhat spongy along the midrib and sparsely pubescent on 
lower surface, usually floating; flowers axillary on long peduncles, raised well 
above the water and lasting only one day; petals light-yellow, obovate, 2-3 cm. 
long; stamens numerous, the outer ones sterile, fertile stamens purple or violet- 
color; pistils usually 6, gradually tapering into the style. 

Cult, in ponds and pools in s. U.S., including e. Tex., and becoming somewhat 
naturalized, summer; nat. of Braz. 

Included here on the basis of Muenscher's report of its occurrence in Texas; 
we have seen no specimens. 

Fam. 23. Hydrocharitaceae Juss. Frog's-bit Family 

Fresh- or salt-water herbs, partly or wholly submerged, dioecious to poly- 
gamo-monoecious, with terrestrial or floating roots; leaves radical and crowded 
or dispersed on elongated stems, alternate to opposite or whorled; flowers regular, 
usually unisexual, arranged in a bifid spathaceous bract or within 2 opposite 
bracts, the staminate usually more than 1, the pistillate solitary; spathe sessile 
to long-pedunculate, the peduncle sometimes spirally twisted; perianth segments 
free to the base, 1- or 2-seriate, 3 or rarely 2 in each series, the outer often green 
and valvate, the inner imbricate and petaloid; stamens 1 to numerous; anthers with 
2 parallel cells that open by longitudinal slits; rudimentary ovary present in the 
staminate flowers; staminodes sometimes present in the pistillate flower; ovary 
inferior, sometimes beaked, 1 -celled, with 3 to 6 or rarely more parietal placentas 
that sometimes protrude nearly to the middle of the ovary; styles as many as 
placentas, entire or 2- or 3-branched; ovules numerous on the placentas; fruit 
globose to linear, dry or pulpy, rupturing irregularly; seeds numerous, without 
endosperm; embryo straight, with a thick radicle and usually inconspicuous 
plumule. 

About 16 genera and 80 species, mainly of tropical and warm temperate 
regions. 

1. Fresh-water plants that are pollinated at or above the surface of the water; 
pollen spheroid (2) 

1. Marine plants that are pollinated beneath the surface of the water; pollen 

confervoid or united in strings (5) 

2(1). Plant floating; leaves broadly ovate to reniform, distinctly petiolate, 

emersed or floating; spathe composed of 1 or 2 free bracts 

1. Limnobium 

2. Plants attached to bottom; leaves linear or straplike, without a petiole, sub- 

mersed; spathe composed of 2 bracts connate into a tube (3) 

3(2). Leaves clustered at the base, straplike, more than 15 cm. long; petals rudi- 
mentary and much smaller than the sepals 2. Vallisneria 

3. Leaves opposite or in approximate whorls on an elongated stem, less than 

5 cm. long; petals well-developed and much larger than the sepals 
(4) 

156 




Fig. 70: Hydrocleis nymphoides: a, top of plant, X ^1>; b, sepal, X IV2; c, carpels, 
XZVs. (V. F.). 




Fig. 71A: Limnobium Spongia: a, habit, X V2; b, pistillate flower, X IVr, c, fruit 
with seeds sprouting, X 1\2- (V. F.). 




Fig. 71B: Limnobium Spongia: a, staminate flower, X 10; b, section of capsule, 
X 21/2; c, seed, X 42. (Courtesy of R. K. Godfrey). 



4(3). Middle and upper leaves in whorls of 4 to 6, averaging about 2.5 cm. long; 

staminate spathes 2- to 4-flowered; petals about 8 mm. wide 

.....3. Egeria 

4. Middle and upper leaves opposite or in whorls of 3 (rarely with some 4), 

rarely more than 2 cm. long; staminate spathes 1-flowered; petals 
1.5 mm. wide or less 4. Elodea 

5(1). Leaves alternate on a short stout concealed stem, ribbonlike, more than 
1 dm. long; spathe composed of 2 bracts connate at the base to 
form a tube 5. Thalassia 

5. Leaves opposite at summit of slender nearly naked stem, mostly oblong- 

elliptic, less than 5 cm. long; spathe composed of 2 free bracts. 
6. Halophila 

1. Limnobium Rich. American Frog's-bit 

Three species centered in tropical America. 
1. Limnobium Spongia (Bosc.) Steud. Common frog's-bit. Figs. 71 A and 7 IB. 

Floating aquatic with pendent roots and stolons; leaves in a basal rosette, 
erect or ascending, with petioles to 15 cm. long, ovate to suborbicular or the 
earlier ones reniform, to 5 cm. broad, obtuse at the apex, truncate to cordate 
at base, entire, faintly 5-nerved, purplish and spongy beneath; flowers unisexual; 
staminate scapes to 1 dm. long, producing 3 or more flowers, filiform, the lance- 
ovoid spathe 3-5 cm. long; pistillate scapes 2-leaved, with 1 or 2 short-pedicelled 
flowers, about 25 mm. long in flower, stout, strongly recurved and elongated in 
fruit; sepals 3, 7-10 mm. long; petals 3, 8-10 mm. long; stamens represented by 



159 




Fig. 72: Vallisneria americana: a, pistillate plant, X V3; b, cross section of leaf, X 
i; c, pistillate flower, X \\i>,; d, top of flower showing stigmas, X 4; e. spathe of stami- 
nate flowers, X 1 '/•>; f and g, two views of staminate flower, X 28; h, capsule, X P/^; 
i, young fruit, X % with fruit enlarged; j, seed, greatly enlarged. (Courtesy of R. K. 
Godfrey). 



3 to 6 subulate rudiments; anthers linear, apiculate, 2-4 mm. long; ovary inferior, 
6- to 9-celled; stigmas filiform, as many as the cells, deeply 2-parted, 1—1.5 cm. 
long, papillose-ciliate; berry ovoid, many-seeded, 1-1.5 cm. long, on a stout 
recurved peduncle. 

In shallow mostly stagnant water of quiet lakes, ponds, lagoons and ditches in 
e. Tex., June-Oct.; from Ont. and N.J., s. to Fla., Tex., Mo. and 111. 

The dense growth often formed by this species provides an excellent habitat for 
small animal life, which apparently attracts marshbirds. The seeds are eaten by 
wildfowl. 

2. Vallisneria L. Tapegrass. Eelgrass 
Two species, one native to America, another in the Old World. 

1. Vallisneria americana Michx. Water-celery. Fig. 72. 

Aquatic dioecious submerged plant from perennial stoloniferous rootstocks with 
fibrous roots and fleshy propagating buds; leaves in basal clusters, linear, obtuse, 
thin, ribbonlike, flaccid, entirely submerged or with the upper part floating, to 
about 6 dm. long and 2 cm. wide, somewhat nerved and netted-veined, often 
minutely denticulate on the margin; staminate spathes 2- or 3-parted, bluntly 
acuminate, 1-2 cm. long, on thick clavate scapes to 5 cm. long; staminate flowers 
numerous, crowded on a short-pedunculate spadix, enclosed in the spathe, 
detached at maturity and floating and expanding on the surface of the water; 
perianth of 3 sepals; stamens 1 to 3; peduncles of the pistillate plant to 1 m. long, 
curved but scarcely spirally twisted in fruit; spathe 2-cleft, 2-2.5 cm. long, rather 
loose; pistillate flowers solitary in the spathe, floating on the water; hypanthium 
linear-cylindric, in flower 2.5-3 cm. long, fully 2 mm. thick, in fruit about 1 dm. 
long; sepals 3, fused to the inferior ovary, oval, 5-6 mm. long, rounded at the 
apex; petals 3, about 2 mm. long; ovary 1-celled, cylindric; stigmas 3, large, about 
5 mm. long, 2-cleft to near the base with each division obliquely obovate and 
abruptly short-acuminate; fruits cylindric, indehiscent, 8-18 cm. long. V. spiralis 
of auth. 

In lakes and beds of flowing streams, rare in the e. half of Tex., N.M. (Rio 
Arriba Co.) and recently discovered in Ariz. (Maricopa Co.), Apr. -July; from 
N.B., w. to N.D., N.M. and Ariz., s. lO Fla. and Tex. 

In our region, this species is too rare to be of much value to wild life. However, 
where it occurs abundantly in the north all parts of the plant are relished by 
many species of waterfowl. It is also eaten by muskrats and is a valuable food 
for fish. Diving ducks are said to be especially fond of the growing tips of the 
rootstocks. The plants also attract various marsh- and shore-birds, and they also 
provide a habitat for minute animal life. 

3. Egeria Planch. 

Two species that are native to South America. 

1. Egeria densa Planch. Fig. 73. 

Perennial submerged aquatic herb of fresh water, dioecious, rooting on the 
bottom or drifting when broken loose; stems terete, slender, 2-3 mm. thick, 
ascending, simple or sparingly dichotomously branched; lower leaves opposite or 
in whorls of 3; middle and upper leaves in whorls of 4 to 6, sessile, crowded, 
pellucid, linear-elliptic to linear-lanceolate, subobtuse to acuminate, serrulate, to 
4 cm. long and 5 mm. wide, much longer than the internodes; flowers unisexual; 
staminate spathes funnelform, sessile, 2- to 4-flowered, borne in the npper axils, 
to 12 mm. long and 3.5 mm. broad, cleft on one side, the apex bifid; flowers 
stipitate, borne to the surface of the water on a threadlike hypanthium 3-6 cm. 

161 




Fig. 73: a-d, Egeria densa: a, stem with whorls of lanceolate leaves, showing their 
minutely serrate margins, X 1%; b, spathe and the flowers, X P^; c, habit, showing 
long-peduncled staminate flowers, X %; d, staminate flower, X 2. e-g, Elodea canaden- 
sis: e, obovoid-clavate spathe with staminate flower on long thread-like peduncle, X 4; 
f, habit, the staminate flower at the surface of the water in anthesis, X %; g, mature 
staminate flower, showing the 9 anthers and 3 rudimentary stigmas, X 5. (From Mason, 
Fig. 53). 



long; sepals 3, herbaceous, elliptic-oblong, 3-4 mm. long; petals 3, white, obovate 
to suborbicular, membranous, about 1 cm. long and 8 mm. wide; stamens 9, 
distinct; anthers loculicidal; filaments glandular-papillose above; nectary central, 
3-lobed, small; pistillate plants not seen. Elodea densa (Planch.) Casp., Anacharis 
densa (Planch.) Vict. 

In lakes, ponds, pools, ditches and quiet streams in Okla. (Comanche Co.) and 
in cen. and e. Tex., also Ariz. (Cochise and Santa Cruz cos.), Apr. -Oct.; a nat. 
of S.A. that has escaped from cult, in various places in the U.S. and Eur. 

The relationship of this species to animal life is similar to that for species 
of Elodea. 

4. Elodea Michx. Waterweed. Ditchmoss 

Submersed dioecious (ours) perennials, adapted for cross-pollination at the 
surface of water, with dichotomously branching and usually nodally rooting slender 
stems; leaves sessile, opposite or in whorls of 3, 1 -nerved, usually minutely dentic- 
ulate; flowers mostly unisexual or occasionally in part perfect, borne in sessile to 
pedunculate bilobed spathes, the sepals and petals 3 each; staminate flowers 1 from 
a somewhat globose spathe, sessile or with a very short pedicellate hypanthium, 
when sessile deciduous from the plant at anthesis and floating on surface of water; 
stamens 3 to 9: pistillate flowers solitary in the tubular spathes, the pedicel-like 
hypanthium elongated to carry the rest of the flower to the water surface; stigmas 
3, simple or bilobed, tending to float, the styles slender; fruit ovoid to cylindric, 
several-seeded. 

About 12 species in temperate and tropical America; one introduced into 
Europe. 

The young, tender leafy stems of species in this genus are apparently only in- 
cidentally eaten by ducks, beaver and muskrats. The dense herbage that is fre- 
quently developed provides a sheltered habitat for small aquatic life but at the 
same time it may suppress the growth of more desirable species. 

1 . Middle and upper leaves opposite or occasionally with at least some in whorls 
of 3, rounded to broadly obtuse at apex (2) 

1. Middle and upper leaves always in whorls of 3, obtuse-apiculate to acute at 

apex (3) 

2(1). Largest leaves usually 1 cm. long or less; pistillate spathe 2-2.2 cm. long, 
the apical teeth erect; in New Mexico in our region....!. E. bifoliata. 

2. Largest leaves usually 1.5 cm. long or more; pistillate spathe 3-7 cm. long, the 

apical teeth divergent; in Arizona in our region. ...2.E. longivaginata. 

3(1). Leaves rarely less than 1.5 mm. wide, obtuse-apiculate at apex; staminate 
flowers with a slender stalk (hypanthium), not deciduous at an- 
thesis; pistillate sepals 2-3 mm. long 3. E. canadensis. 

3. Leaves rarely more than 1.5 mm. wide, acute at apex; staminate flowers sessile, 

deciduous from plant at anthesis and floating on the surface of the 
water; pistillate sepals about 1 mm. long 4. E. Nuttallii. 

1. Elodea bifoliata St. John. 

Stems slender, dichotomously branched; middle and upper leaves opposite or 
occasionally with at least some in whorls of 3, linear to lance-linear, rounded 
to broadly obtuse at apex, finely serrulate, the longer ones 6-10 mm. long and 
1-1.5 mm. wide, bright green and flaccid; staminate spathe narrowed below into 
a slender petiolelike base 6-8 mm. long, the upper portion ellipsoid-inflated and 
5 mm. long; flower peduncled by the slender threadlike hypanthium; sepals and 
petals 3.5 mm. long; stamens 9, raised on a very short common stalk; pistillate 
spathe 2-2.2 cm. long, the flower exserted by the very slender threadlike elongated 
hypanthium that becomes 9-12 cm. in length; sepals L4 mm. long and petals L8 

163 




Fig. 74:, a-f, Elodea longivafyinata: a, habit, X Vo; b, young staminate flower and 
spathe, X 3; c, mature staminate flower, X 3; d, mature capsule, X 3; e, seeds, X 3; f, 
leaf, X 21/2. g, Elodea Nuttallii: g, leaf, X 21/2. (V. F.). 



mm. long; staminodia 3, linear, obtuse; stigmas 3, bidentate, papillose. 

In ponds and sloughs in Ariz. (Coconino Co.), May-Oct.; apparently endemic. 

2. Elodea longivaginata St. John. Fig. 74. 

Stems elongate, slender, sparingly dichotomously branched; middle and upper 
leaves opposite or occasionally with at least some in whorls of 3, linear, rounded 
to broadly obtuse at apex, finely serrulate especially near and at the tip, the longer 
ones 1.5-2.6 cm. long and 1-2.5 mm. wide, bright green and flaccid, scarcely 
imbricate; staminate spathe short- to long-pedunculate, 6-10 mm. long, 1 -flowered; 
flower with an elongate threadlike hypanthium to about 3 dm. long, with sepals 
about 4 mm. long and petals 5 mm. long; stamens 9, all attached at the summit of 
the hypanthium; pistillate spathe (and stalk) 3-7 cm. long, the flower with a 
threadlike hypanthium that elongates to about 3 dm. long so as to bear the flower 
to the surface of the water; sepals 2.8 mm. long and petals 4 mm. long; staminodia 

3. ligulate; stigmas 3, oblong, undivided; capsule about 1 cm. long; seeds cylindric, 
6 mm. long. 

Submersed in water of lakes, ponds, sloughs and quiet running water in N.M. 
(Mora, Rio Arriba and San Miguel cos.), June-Oct.; from Alta. to N. D., s. to 
Mont., Wyo., Colo., N. M. and Ut. 

.3. Elodea canadensis Rich, in Michx. Fig. 73. 

Stems elongate, slender dichotomously branched; middle and upper leaves in 
whorls of 3, linear to lance-oblong, mostly 8-15 mm. long and 1.5-3 mm. wide, 
rarely larger, bright green, thin, flaccid, finely serrulate, strongly imbricate at tip 
of stems (especially in pistillate plants); staminate spathe with a narrowed pedun- 
culate base, inflated, ellipsoid to ovoid, 7 mm. long and 4 mm. wide; flowers 
peduncled by the slender threadlike elongate base of hypanthium, with the sepals 
3.5-5 mm. long and petals 5 mm. long; stamens 9, with the 3 inner ones raised 
on a common fused stalk; pistillate spathe cylindric; flowers exserted from the 
spathe by the threadlike elongate base of the hypanthium which is to 15 cm. 
long; sepals and petals 2-3 mm. long; staminodia 3, acicular; stigmas 3, 4 mm. 
long, broad, 2-cleft at apex; capsule ovoid, 6 mm. long; seeds narrowly cylindric, 
4.5 mm. long, glabrous. Anacharis canadensis (Rich, in Michx.) Rich. 

In lakes, ponds and slow-moving streams, especially in calcareous areas, re- 
ported (but not seen) from Okla., in N. M. (Sandoval and Taos cos.) and Ariz. 
(Coconino and Navajo cos.), June-Oct.; from Que. to Sask., s. to Va., Ala., (?) 
Okla., N. M., Ariz, and Calif.; also introd. in Eur. 

4. Elodea NuttaUu (Planch.) St. John. Fig. 74. 

Stems slender, dichotomously branched, often freely so; middle and upper leaves 
in whorls of 3 or occasionally with some in 4's, linear to narrowly lance-linear, 
6-13 mm. long, 0.3-1.5 mm. wide, rarely more, acute at apex, green and flaccid, 
finely serrulate; staminate spathe borne at the median axils, sessile, ovoid, apicu- 
late, 2-parted to well below the middle, the 2 acuminate teeth often twisted to 
form the apiculate tip, the body 2 mm. long; flower single in each spathe, sessile, 
at maturity breaking loose to float to the surface and there opening; sepals about 
2 mm. long and 1.6 mm. wide; petals usually wanting or (when occasionally 
present) 0.5 mm. long; stamens 9, the 3 central ones slightly elevated on a com- 
mon stalk, the 6 outer ones at a lower level and with separate filaments; pistillate 
spathe narrowly cylindric, somewhat ovoid at base, usually 1-1.5 cm. long; flower 
stalked by a slender threadlike elongated hypanthium as much as 9 cm. in length; 
sepals 1.1 mm. long and petals 1.3 mm. long; staminodia 3, 0.5 mm. long, 
acicular; stigmas 3, slender, bifid, somewhat exceeding the sepals; capsule sessile, 
narrowly ovoid to fusiform, 5-7 mm. long, 1.5-2 mm. in diameter; seeds cylindric, 
short-beaked, 3.5-4.5 mm. long, pilose. Anacharis Nuttallii Planch., A. occidentalis 
(Pursh) Marie- Vict. 

165 




Fig. 75A: Thalassia testudinum: a, habit, X V.; b, rhizome showing sheaths and 
fibers, X 2; c, leaf tip, X ly-,- (a. Courtesy of R. K. Godfrey, b, c, V. F.). 




Fig. 75B: Thalassia testmUnum: a, staminate flower, enlarged; b, pistillate flower 
enlarged. (Courtesy of R. K. Godfrey). 



In fresh or rarely brackish water, commonly in still water of streams, in Okla. 
(Alfalfa, Delaware, Ottawa and Sequoyah cos.) and N. M. (Taos Co.), May-Oct.; 
Que. to N. C, westw. to Minn., Okla. and N. M.; also Ida. 



5. Thalassia Sol.^nd. 



Turtle-grass 



Several species in marine waters of tropical and warm temperate regions. 

1. Thalassia testuduium Konig, Palmas del mar. Figs. 75A and 75B. 

Submersed perennial herb with thick creeping scaly rhizome 3-5 mm. thick, 
dioecious; the short stems covered by the fibrous remains of old leaves; leaves 
several, 2-ranked, clustered on short erect branches, sheathing at base, linear, 
to 35 cm. long and 1 cm. wide, glabrous, minutely serrulate at the obtuse- 
rounded apex, withering-persistent; scapes arising from the leaf axils, bearing a 
solitary unisexual flower in a 2-cleft tubular spathe whose lobes are elliptic and 
papillose-dentate on the margins; staminate flowers pedicelled; pistillate flower 
nearly sessile in the spathe; perianth lobes 6, in both kinds of flowers oblong, 
rounded above, 1-1.2 cm. long; stamens 9; anthers about 8 mm. long, linear, 
opening laterally; stigmas 9 to 12, linear-filiform, pilose, grooved on the inside, 
about 1 cm. long; fruit oval to ellipsoid-fusiform, short-stalked and short-beaked, 
densely warty-mammillate, opening by valves, 2 cm. or more long. 

In shallow salt water along the Gulf Coast where it forms dense and extensive 
marine meadows in bays and about reefs, occasional in beach drift; from Fla. to 
Tex., s. to n. S. A. 



167 




Fig. 76: Halophila Engelmannii: a, habit, X %; b, young leaf, X 1. (Courtesy of 
R. K. Godfrey). 



6. Halophila Thou, 

Several species widespread in marine waters of tropical and warm temperate 
regions. 

1. Halophila Engelmannii Asch. Fig. 76. 

Submersed perennial with horizontal slender creeping scaly branching stoloni- 
ferous stems 1-1.5 mm. thick that root at the nodes and produce short erect 
leafy branches; internodes 2-4 cm. long; scales and leaves in pairs, opposite; 
scales broadly obovate, glabrous, to about 1 cm. long; erect shoots 2-4 cm. long, 
with 1 pair of scales at the middle and 2 or 3 pairs of leaves clustered at the 
summit; leaves sessile or with a very short thick petiole 2 mm. long or less, linear- 
oblong to oblong-elliptic, obtuse to subacute at apex, tapering at base, to 4 cm. 
long and 8 mm. wide, rather thick, faintly 3-ribbed and with 6 to 8 pairs of lateral 
veins, reticulate-roughened, finely serrulate on the margins; flowers 1 or 2 enclosed 
in a bifoliate sheath, both kinds often in the same sheath; pistillate flowers sessile 
in the axils of the leaves; hypanthium ovoid, 3-4 mm. long, its neck about 5 mm. 



168 



long; sepals 3, minute; stigmas 3, filiform, sessile, channeled and with usually 
2 rows of papillae; fruit a membranous capsule with 3 parietal placentae, enclosed 
in the sheath; seeds numerous; staminate flowers not seen. 

In shallow salt water along the Gulf Coast, occasional in beach drift; from 
Fla to Tex., the Bah. I. and W. I. 

Ottelia alismoides (L.) Pers. Vegetatively resembling a large, coarse Plantago; 
leaves thin, submerged or partly emersed, broadly ovate to suborbicular or cordate- 
reniform, to 21 cm. in diameter, with 7 to 1 1 prominent parallel curved veins; 
peduncle several-angular, to 3 dm. tall; spathe elliptic to ovate, with 2 acute tips, 
1 -flowered; flowers sessile, fragrant; sepals linear to oblong, obtuse, 1 -nerved, to 
16 mm. long and 4 mm. wide; petals obovate, 2-3 cm. long, white to very pale 
pink, slightly darker distally yellow-based; anthers bright yellow; fruit oblong, 
rostrate, 2-4 cm. long, crowned by the sepals, bursting irregularly. 

This Afro-Asian plant has recently been found in Cameron Parish, Louisiana, 
in shallow, clear water in McCain's Fishing Lake, about 3 miles southwest of 
Sweet Lake (15 miles south of Lake Charles), about 30 miles east of the Texas 
state line. It probably is only a matter of time before it is found in similar locations 
in Texas. 

Fam. 24. Gramineae Juss. Grass Family 

Herbs or less commonly woody reedlike plants; roots fibrous; leaves distichous, 
each with a more or less sheathing lower portion ("sheath") and a terminal usually 
more or less linear blade, often at the juncture of sheath and blade an adaxial 
fringe- or scalelike structure ("hgule"); in each axil often a small 2-nerved 
asymmetric (in transection often H-shaped) structure ("prophyll"); leaves often 
with a meristem near the ligule that permits continued elongation; flowers (florets) 
very much reduced, perfect or neuter, less commonly staminate or pistillate, 
usually aggregated distichously in small clusters known as spikelets, each flower 
comprising the genitalia (when present) at the base of which are usually 2 minute 
bulbs or scales ("lodicules"), this floret subtended usually by a minute adaxial 
prophyll-like bract scale (palea) and a slightly larger abaxial bract scale (lemma); 
lemmas (when more than one present) distichous on the spikelet axis (rachilla); 
base of spikelet usually with 2 empty bract scales (glumes), or one of these some- 
times obsolete or rarely both glumes absent; perianth absent; stamens 1 to 6 
(usually 3); ovary a usually dorsiventrally flattened 1 -celled uniovulate structure; 
style deeply divided into 2 (rarely 3) long feathery stigmas; fruit ("grain," 
"caryopsis") an achenelike structure but with the ovary wall usually tightly co- 
herent to the solitary endosperm-containing seed (ovary wall apparently not per- 
sistently tightly adherent to seed in Sporobolus and some species of Muhlenbergia) , 
or in some genera (e.g., Panicum, etc.) the word "fruit" is used to refer to the 
lemma and its contents since in these plants the lemma tightly and persistently 
clasps the grain and thus constitutes a spurious outer fruit layer. Poaceae Barnh. 

One of the largest families of flowering plants, the Gramineae are the most im- 
portant economically as measured by several criteria. They produce the dietary 
staples of most of the world's population. One species, rice, is the most important 
of all the grasses and probably the single most important plant species in the 
world. 

(Many data, including an adaptation of the generic key, have been derived 
from the work of A. S. Hitchcock, Manual of the Grasses of the United States, 
U. S. Dept. Agric. Misc. Publ. No. 200, 2nd ed. revised by Agnes Chase, 1055 pp. 
1950.) 

169 



1. Spikelets with 1 perfect terminal floret and a sterile or staminate floret below, 
usually represented by a sterile lemma only, 1 glume sometimes 
wanting; the rachilla articulated below the spikelets, the spikelets 
thus falling entire (2) 

1. Spikelets 1- to many-flowered, the reduced florets (if any) above the perfect 

florets (except in Phalaris); the rachilla usually articulated above 
the glumes (except in Leersia, Polypogon, Alopecurm, Spartino 
and Agrostis semiverticillata) (16) 

2(1). Glumes membranaceous, the sterile lemma like the glumes in texture (3) 

2. Glumes indurate; fertile lemma and palea hyaline or membranaceous, the 

sterile lemma like the fertile one in texture (12) 

3(2). Spikelets subtended or surrounded by 1 to many distinct or more or less 
connate bristles forming an involucre (4) 

3. Spikelets not subtended by bristles (5) 

4(3). Bristles persistent, the spikelets deciduous 55. Setaria 

4. Bristles falling with the spikelets at maturity 56. Cenchrus 

5(3). Glumes or sterile lemma awned (awn reduced to a point in Echinochloa 
colonum) 54. Echinochloa 

5. Glumes and sterile lemma awnless (6) 

6(5). Fruit cartilaginous-indurate, flexible, usually dark-colored, the lemma with 
more or less prominent white hyaline margins that are not inrolled 
(7) 

6. Fruit chartaceous-indurate, rigid (8) 

7(6). Spikelets in slender racemes more or less digitate at the summit of the 
culms 48. Digitaria 

7. Spikelets in panicles 47. Anthaenantia 

8(6). Spikelets placed with the back of the fruit turned away from the rachis 
of the racemes, usually solitary (not in pairs) (9) 

8. Spikelets placed with the back of the fruit turned toward the rachis (first 

glume, when present, away from the rachis) of the spikelike ra- 
cemes or pedicellate in panicles (10) 

9(8). First glume and the rachilla joint forming a swollen ringlike callus below 
the spikelet 49. Eriochloa 

9. First glume present or wanting, not forming a ringlike callus below the spike- 

let 50. Axonopus 

10(8). First glume typically wanting; spikelets plano-convex, subsessile in spike- 
like racemes 51 . Paspalum 

10. First glume present; spikelets usually in panicles (11) 

11(10). Second glume inflated-saccate, this and the sterile lemma much exceed- 
ing the stipitate fruit 53 Sacciolepis 

11. Second glume not inflated-saccate 52. Panicum 

12(2). Spikelets unisexual, the pistillate below, the staminate above, in the same 
inflorescence or in separate inflorescences 61. Tripsacum 

12. Spikelets in pairs, one sessile and perfect, the other pedicellate and usually 

staminate or neuter (the pedicellate one sometimes obsolete, rarely 
both pedicellate); lemmas nyaline (13) 

13(12). Spikelets alike, all perfect 57. Erianthus 

13. Spikelets unlike, the sessile perfect, the pedicellate sterile (14) 

14(13). Pedicel thickened, appressed to the thickened rachis joint (at least 
parallel to it) or adnate to it; spikelets awnless, appressed to the 
joint 60. Manisuris 

170 



14. Pedicel not thickened (if slightly so the spikelets awned), neither appressed 

nor adnate to the rachis joint, this usually slender; spikelets usually 
awned (15) 

15(14). Fertile spikelet with a hairy-pointed caHus, formed of the attached sup- 
porting rachis joint or pedicel; awns strong 58. Andropogon 

15. Fertile spikelet without a callus, the rachis disarticulating immediately below 

the spikelet; awns slender 59. Sorghum 

16(1). Culms woody, perennial; leaf blades articulated with sheaths 

1. Arundinaria 

16. Culms herbaceous, annual (somewhat woody and persistent in Arundo); leaf 

blades and sheaths continuous (17) 

17(16). Spikelets with 2 (rarely 1) staminate, neuter or rudimentary lemmas 
unlike and below the fertile lemma; no sterile nor rudimentary 
floret above (18) 

17. Spikelets without sterile lemmas below the perfect floret (19) 

18(17). Lower florets staminate; spikelets brown, shining 40. Hierochloe 

18. Lower florets neuter; spikelet green or yellov/ish 41. Phalaris 

19(17). Spikelets unisexual, falling entire, 1-flowered, terete or nearly so (20) 

19. Spikelets perfect (rarely unisexual but then not as above), usually articulate 

above the glumes (22) 

20(19). Culms slender; floating aquatic; staminate and pistillate spikelets borne 
in separate inflorescences 46. Hydrochloa 

20. Culms robust; plants tall, usually standing in water; staminate and pistillate 

spikelets borne in the same panicle (21) 

21(20). Pistillate spikelets on the ascending upper branches, the staminate on 
the spreading lower branches of the panicle; annual or perennial.... 
44. Zizania 

21. Pistillate spikelets at the ends, the staminate below on the same branches 

of the panicle; perennial 45. Zizaniopsis 

22(19). Spikelets articulate below the glumes, 1-flowered, very flat, the lemma 
and palea about equal, both keeled; glumes small or wanting (23) 

22. Spikelets articulate above the glumes (rarely below, but at least one of the 

glumes well-developed) (24) 

23(22). Glumes minute; lemma often awned 42. Oryza 

23. Glumes wanting; lemma awnless 43. Leersia 

1A{T1). Spikelets sessile on a usually continuous rachis (short-pedicellate in 
Leptochloa; the rachis disarticulating in Hordeum) (25) 

24. Spikelets pedicellate in open or contracted sometimes spikelike panicles, rarely 

racemes (34) 

25(24). Spikelets on opposite sides of the rachis; spike terminal, solitary (26) 

25. Spikelets on one side of the rachis; spikes usually more than 1, digitate or 

racemose (30) 

26(25). Spikelets solitary at each node of the rachis (rarely 2 in species of 
Agropyron, but never throughout) (27) 

26. Spikelets more than 1 at each node of the rachis (solitary in part of the spike 

in some species of Ely mux) (29) 

27(26). Spikelets 1-flowered, sunken in hollows of the rachis; spikes slender, 
cylindric; low annuals 20 Parapholis 

27. Spikelets 2- to several-flowered, not sunken in the rachis (28) 

171 



28(27). Spikelets placed edgewise to the rachis; first glume wanting except in the 
terminal spikelet 19. Lolium 

28. Spikelets placed flatwise to the rachis 16. Agropyron 

29(26). Spikelets 3 at each node of the rachis, 1 -flowered, the lateral pair 
pediceled, usually reduced to awns 18. Hordeum 

29. Spikelets 2 or more (occasionally solitary) at each node of the rachis, alike, 

2- to 6-flowered 17. Elymus 

30(25). Spikelets wtih more than 1 perfect floret 35. Leptochloa 

30. Spikelets with only 1 perfect floret, often with additional imperfect florets 

above or below (31) 

31(30). Spikelets with 1 or more modified florets above the perfect one 

39. Trichloris 

31. Spikelets without additional modified florets, the rachilla sometimes pro- 

longed (32) 

32(31). Rachilla articulate above the glumes 36. Cynodon 

32. Rachilla articulate below the glume, the spikelets falling entire (33) 

33(32). Glumes unequal, narrow 38. Spartina 

33. Glumes equal, broad, boat-shaped 37. Beckmannia 

34(24). Spikelets 1-flowered (occasionally some of the spikelets 2-flowered in 
a few species of Muhlenbergia) (35) 

34. Spikelets 2- to many-flowered (44) 

35(34). Articulation below the glumes, the spikelets falling entire (36) 

35. Articulation above the glumes (38) 

36(35). Glumes long-awned 30. Polypogon 

36. Glumes awnless (37) 

37(36). Rachilla prolonged behind the palea; panicle narrow or open, not dense; 
glumes not united, not ciliate on the keel 28. Cinna 

37. Rachilla not prolonged behind the palea; panicle dense 29. Alopecurus 

38(35). Glumes longer than the lemma (39) 

38. Glumes not longer than the lemma, usually shorter (the awn tips longer in 

Muhlenbergia racemosa) (42) 

39(38). Glumes compressed-carinate, stiff-ciliate on the keel; panicle dense, 
cylindric or ellipsoid 31. Phlewn 

39. Glumes not compressed-carinate, not ciliate (40) 

40(39). Glumes saccate at base; lemma long-awned; panicle contracted, shining 
32. Gastridium 

40. Glumes not saccate at base; lemma awned or awnless; panicle open or con- 

tracted (41) 

41(40). Floret bearing a tuft of hairs at the base from the short callus; palea 
well-developed, the rachilla prolonged behind the palei as a hairy 
bristle 26. Calamagrostis 

41. Floret without hairs at the base or with short hairs; palea usually small or 

obsolete 27. Agrostis 

42(38). Lemma awned from the tip or mucronate, 3- to 5-nerved or obscure in 
some species 33. Muhlenbergia 

42. Lemma awnless or awned from the back (43) 

43(42). Caryopsis at maturity falling from the lemma and palea; seed loose in 

the pericarp, this usually opening when ripe; lemma 1 -nerved 

34. Sporobolus 

111 



43. Caryopsis not falling from the lemma and palea, remaining permanently en- 

closed in them; seed adnate to the pericarp 33. Muhlenbergia 

44(34). Glumes as long as the lowest floret, usually as long as the spikelet 
(sometimes shorter in Sphenopholis) ; lemmas awned from the back 
(spikelets awnless in species of Trisetum and Sphenopholis) (45) 

44. Glumes shorter than the first floret (except in Tridens strictus); lemmas awn- 

less or awned from the tip or from a bifid apex (50) 

45(44). Florets 2, one perfect, the other staminate 24. Holcus 

45. Florets 2 or more, all alike except the reduced upper ones (46) 

46(45). Articulation below the glumes, the spikelets falling entire (47) 

46. Articulation above the glumes, the glumes similar in shape (48) 

47(46). Lemmas (at least the upper) with a conspicuous bent awn; glumes 
nearly alike 22. Trisetum 

47. Lemmas awnless or the upper with a short awn; second glume much wider 

than the first 21. Sphenopholis 

48(46). Lemmas bind at apex, awned or mucronate between the lobes; spikelets 
several-flowered 25. Danthonia 

48. Lemmas toothed but not bifid and awned or mucronate between the lobes 

(49) 

49(48). Lemmas keeled, the awn when present from above the middle 

22. Trisetum 

49. Lemmas convex, awned from below the middle 23. Deschampsia 

50(44). Tall stout reeds with large plumelike panicles; lemmas and rachilla with 
long silky hairs as long as the lemmas (51 ) 

50. Low or rather tall grasses, rarely more than 1.5 m. tall; panicles not as above 

(52) 

51(50). Lemmas naked; rachilla hairy 14. Phragmites 

51. Lemmas hairy; rachilla naked 13. Arundo 

52(50). Plants dioecious, perennial (53) 

52. Plants not dioecious (except in the annual Eragrostis reptans) (54) 

53(52). Plants low, stoloniferous; spikelets obscure, scarcely differentiated from 
the short crowded rigid leaves 9. Monanthochloe 

53. Plants erect from creeping rhizomes; spikelets in narrow simple exserted 

panicles 10. Distichlis 

54(52). Lemmas 3-nerved, the nerves prominent, often hairy (55) 

54. Lemmas 5- to many-nerved, the nerves sometimes obscure (57) 

55(54). Inflorescence a few-flowered head or capitate panicle overtopped by the 
leaves or partly concealed in them; lemmas toothed or cleft; low 
plants of usually arid regions 15. Tridens 

55. Inflorescence an exserted open or spikelike panicle (56) 

56(55). Lemmas pubescent on the nerves or callus, the midnerve usually exserted 
as an awn or mucro 15. Tridens 

56. Lemmas not pubescent on the nerves nor callus (the internerves sometimes 

pubescent), awnless 8. Eragrostis 

57(54). Spikelets with 1 to 4 empty lemmas below the fertile florets; nerves ob- 
scure; lemmas firm 11. Chasmanthium 

57. Spikelets with no empty lemmas below the fertile florets; nerves usually 

prominent; lemmas membranous (firm in a few species of Bromus 
and Festuca) (58) 

173 




Fig. 77: Arundinaria gigantea: flowering shoot, X V^; summit of culm sheath, outer 
and inner face, showing auricles and ligule, and two views of floret, X 2. (From Hitch- 
cock & Chase). 



58(57). Lemmas as broad as long, the margins outspread; florets closely imbri- 
cate, horizontally spreading 7. Briza 

58. Lemmas longer than broad, the margins clasping the palea; florets not hori- 

zontally spreading (59) 

59(58). Lemmas keeled on the back (60) 

59. Lemmas rounded on the back (slightly keeled toward the summit in Festuca 

and Bromus) (62) 

60(59). Spikelets strongly compressed, crowded in 1 -sided clusters at the ends 
of the stifif naked panicle branches 12. Diictylis 

60. Spikelets not strongly compressed, not crowded in 1 -sided clusters (61) 

61(60). Lemmas awned from a minutely bifid apex; spikelets large 2. Bromus 

61. Lemmas awnless; spikelets small 6. Poa 

62(59). Nerves of lemma parallel, not converging at summit or but slightly so 
(63) 

62. Nerves of lemma converging toward the summit, the lemmas narrowed at 

apex (64) 

63(62). Nerves prominent; plants usually rather tall, growing in fresh-water 
marshes or wet woodlands 5. Glyceria 

63. Nerves faint; plants low, usually growing in saline soils 4. Puccinellia 

64(62). Lemmas awned or awn-tipped from a minutely bifid apex; palea ad- 
hering to the caryopsis 2. Bromus 

64. Lemmas entire, pointed, awnless or awned from the tip (65) 

65(64). Spikelets awned (awnless in a few perennial species); lemmas pointed.... 
3. Festuca 

65. Spikelets awnless 6. Poa 

1. Anindinaria Michx. 

About 150 species in warmer parts of the world; one species in our area. 

1. Anindinaria gigantea (Walt.) Muhl. Giant cane. Fig. 77. 

Mostly glabrous robust rhizomatous cane-grass forming dense brakes; primary 
aerial culms perennial (not usually freezing back), 2-8 m. tall, 2-20 mm. thick, 
erect, with some ascending or appressed branches along the length; sheath margins 
ciliate; small sheath auricles usually with a few spreading bristles; blades very 
shortly petiolate, of two size-classes, larger ones on the primary aerial culms 
12-20 cm. long and 10-25 mm. broad, smaller ones on the branches; inflores- 
cences narrowly paniculate, the lower pedicels mostly included in the sheath and 
the upper ones free (most of them nearly as long as their spikelets); spikelets 
few, 5-8 cm. long, about 8 mm. broad, 9- to 1 3-flowered, lax enough so that the 
internodes of rachis are often visible; zone of abscission at lower part of each 
lemma node; lower lemmas 22-25 mm. long, cymbiform, finely pubescent, 
obscurely 1 1 -nerved, with fine awnlike tips. 

Locally forming brakes in low areas near sloughs, bayous and rivers, in s.e. 
Okla. {Waterfall) and in e. and s.e. Tex., s.w. to Wharton Co., spring; s.e. U. S,, 
n. to N. C, O. and Ind. 

Giant cane formerly covered many square miles in east and southeast Texas 
but with the introduction of domestic stock it has almost disappeared and is 
now relatively rare. 

2. Bromus L. Chess. Brome 

Plant diverse in habit; inflorescense an open or dense panicle; spikelets diverse, 
large, either strongly compressed or turgid, several-flowered with all the flowers 

175 




Fig. 78: Bromus Richardsonii: plant, X \^; spikelet and floret, X 5. (From Hitch- 
cock & Chase). 



perfect; rachilla glabrous, abscising above the glumes and below the florets; glumes 
1- to 5-nerved, shorter than the lower lemma; lemmas basally not calloused or 
else with a glabrous callus, 5- to 9-nerved, apically narrowed or bifid, the nerves 
converging toward the summit, mucronate or awned either between the teeth 
or from the back shortly below the apex. 

A genus of about 150 species in temperate regions. Some European authors 
split Bromus into several genera, perhaps justly. 

1. Panicle branches elongate, drooping; lemmas mostly 5-6 mm. wide, at first 
membranous, eventually becoming slightly chartaceous and only the 
lower part of the margin becoming revolute, the back rather evenly 
pubescent 1. B. japonicus. 

1. Panicle branches relatively short, ascending; lemmas mostly 6-8 mm. wide, 
at first membranous but soon becoming chartaceous and the margin 

partly revolute, the upper portion of back glabrous 

, 2. B. Richardsonii. 

1. Bromus japonicus L. Japanese chess. 

Annual; culms 3-8 dm. long, ascending, slender, sheaths and blades usually 
shortly pilose; blades mostly 2-5 mm. broad; panicle 1-2 dm. long, 1-sided 
(when mature) nodding with several long curved drooping few-flowered branches 
at the base; spikelets turgid, 7- to 10-flowered; lemmas with awns 5-11 mm. 
long, (at first straight or eventually slightly curved and spreading) and bodies 7-9 
mm. long and 5-6 mm. broad, broadly overlapping, the thin margins conspicuous 
and eventually (very late in maturation) becoming chartaceous and the margins 
revolute to clasp the palea which is conspicuously shorter; anthers 0.6-1.2 mm. 
long. 

Abundant weed in wet meadows and ditches, in Okla. {Waterfall) and in 
scattered parts of Tex. (rare in Trans-Pecos), and Ariz. (Apache, Navajo, 
Coconino, Gila, Cochise and Pima cos.), spring; widespread in temp, parts of 
Euras. and N.A. 

2. Bromus Richardsonii Link. Fig. 78. 

Tufted perennial; culms 4-8 dm. long, about 2 mm. thick, often decumbent 
in the lower part and geniculate; sheaths usually glabrous; blades 5-15 mm. broad, 
mostly flat, the lower comers (where joining sheath) minutely round-auricled; 
panicles nodding, 1-2 dm. long, very open and diffuse; spikelets 6- or 7-flowered; 
first glume 1 -nerved, the second 3-nerved; lemmas not at all keeled (except when 
very immature), cymbiform with a body 10-13 mm. long and an awn 3-5 mm. 
long, densely pubescent near the lateral margins but the median portion glabrous. 
Zerna Richardsonii (Link) Nevskii. These plants have usually been called B. 
ciliatus L. 

On lake and pond margins, in seepage areas and along wettish river banks, 
also moist woods and rocky slopes, in higher parts of mts. in the Tex. Trans-Pecos, 
N. M. (rather widespread) and Ariz. (Apache, Coconino, Yavapai, Graham, 
Cochise and Pima cos.), summer; Rocky Mts. and s. to Tex. 

3. Festuca L. Perennial Fescue 

Tufted perennials 1-11 dm. tall; spikelets very slightly if at all laterally com- 
pressed, 2- to 8-flowered, most of the flowers perfect and chasmogamous but 
the uppermost staminate or rudimentary; lower glume usually well-developed, 
l-nerved; upper glume usually merely pointed though less commonly awned, 
usually 3-nerved (but the lateral nerves obscure); spikelet rachilla disarticulating 
at the lower part of each node (i.e., top of each internode); lemmas usually 
ovate or elliptic, blunt to acute, awned or awnless, cymbiform and/ or convex, 
not keeled (except slightly in F. rubra), revolute, 5-nerved (lateral nerves ob- 
scured); anthers 3, free, exserted; grains ellipsoid or ovoid. 

177 




P^g- "79: Festiica rubra: plant, X \^; spikelet and floret, X 5. (From Hitchcock & 



A moderately large genus of temperate regions of the world. 

1. Blades involute; lemmas lanceolate, with awns 1-4 mm. long 1. F. rubra. 

1, Blades flat for at least a part of their length; lemmas elliptic, awnless, acute 
2. F. obtusa. 

1. Festuca rubra L. Red fescue. Fig. 79. 

Tufted perennial; culms 1-5 dm. long, 0.5-1 mm. thick, usually decumbent at 
the base, reddish-fibrillose and subrhizomatous, otherwise erect; ligules extremely 
short to obsolete; panicles interrupted-spikelike (or more lax with a few very 
short ascending branches in the lower part floriferous nearly to their bases), 
4-12 cm. long; pedicels 1-2 mm. long, appressed; spikelets laterally compressed, 
3- to 5-flowered; lemmas lanceolate, very slightly (if at all) keeled near the apex, 
marginally thin and revolute, apically long-tapered, acute with an awn 1-4 mm. 
long, the lowest with bodies 5—7 mm. long. 

In wet meadows, bogs and marshes, rare in highest parts of Madera Canyon, 
Davis Mts. in the Tex. Trans-Pecos and Ariz. (Apache and Coconino cos.), 
summer; widespread in the cooler parts of the N. Hemis., in Am. s. in the mts. 
to S. C, Ala. and Mex. 

2. Festuca obtusa Biehler. Nodding fescue. 

Tufted perennial; culms 5-1 1 dm. long, 1-2 mm. thick, basally shortly decum- 
bent, usually geniculate at the lower nodes; blades 3-8 mm. broad, flat at least 
part of their length; panicles 12-25 cm. long, usually less than half as thick, more 
or less open, nodding, with several branches, the long lower ones naked in at 
least the basal two-thirds to three-fourths their lengths; pedicels 2-4 mm. long, 
appressed; spikelets turgid, 2- to 5-flowered; lemmas elliptical, not at all keeled, 
convex, marginally thin, eventually revolute, the lowest lemmas 3.5-4.5 mm. 
long, awnless, apically acute (the angle broad, blunt), eventually turning greenish- 
stramineous, the lateral nerves very obscure. 

Scarce in woods, on shores of ponds and alluvial soil along streams, in Okla. 
(Alfalfa Co.) and in e. Tex., spring; e. U.S., w. to N.D., S.D., Neb., Kan., Okla. 
and Tex. 

4. Puccinellia Parl, Alkali-grass 

Low pale smooth tufted annuals or perennials with narrow to open panicles; 
spikelets several-flowered, usually terete or subterete, the rachilla disarticulating 
above the glumes and between the florets; glumes unequal, shorter than the first 
lemma, obtuse or acute, rather firm, often scarious at the tip, the first 1 -nerved 
or sometimes 3-nerved, the second 3-nerved; lemmas usually firm, rounded on 
the back, obtuse or acute, rarely acuminate, usually scarious and often erose at 
the tip, glabrous or puberulent toward base, rarely pubescent on the nerves, 
5-nerved, the parallel nerves indistinct or rarely prominent; palea about as long 
as the lemma or somewhat shorter. 

About 100 species in the North Temperate Zone and in South Africa. 

1. Lemmas pubescent on the nerves for one half to three fourths their length; 
dwarf annual 1. P. Parishii. 

1. Lemmas glabrous or (if pubescent) the hairs not confined to the nerves; 

perennials (2) 

2(1). Lemmas 2 mm. long or less; anthers 0.5-0.8 mm. long; lower panicle 

branches usually reflexed, spikelet-bearing mainly near the tip 

2. P. distans. 

2. Lemmas usually 2.5-3.2 mm. long; anthers usually more than 0.8 mm. long; 

lower panicle branches often erect, usually spikelet-bearing most of 
their length 3. P. Nuttalliana. 

179 




Fig. 80: Glyceria borealis: a, panicle, X %; b, habit, showing the slender culms, 
leaves and the panicles, X %; c, spikelet, X 6; d, grain, X 20; e, floret, showing the 
palea and broadly scarious tip of lemma, X 12; f, leaf sheath, blade and ligule, X 4. 
(From Mason, Fig. 68). 



1. Puccinellia Parishii Hitchc. 

Annual; culms 3-10 cm. tall; blades flat to subinvolute, less than 1 mm. wide; 
panicle narrow, few-flowered, 1^ cm. long; spikelets 3- to 6-flowered, 3-5 mm. 
long; lemmas about 2 mm. long, obtuse to truncate, scarious and somewhat erose 
at the tip, pubescent on the mid and lateral nerves nearly to the apex and on 
the intermediate nerves about half way. 

In marshy ground in N. M. (Taos Co.) and Ariz. (Navajo and Coconino cos.); 
also s. Calif. 

2. Puccinellia distans (L.) Pari. 

Perennial; culms erect or decumbent at base, 2-4 dm. tall, sometimes taller; 
blades flat or more or less involute, mostly 2-4 mm. wide; panicle pyramidal, 
loose, 5-15 cm. long, the branches fascicled, rather distant, the lower spreading 
or finally reflexed, the longer ones naked half their length or more; spikelets 
4- to 6-flowered, 4-5 mm. long; glumes 1-2 mm. long; lemmas rather thin, 
obtuse or truncate, 1.5-2 mm. long, with a few short hairs at base; anthers about 
0.8 mm. long. 

In wet meadows, marshes and wet more or less alkaline soils, in N. M. (San 
Juan, Rio Arriba and Taos cos.); Que. to B.C., s. to Md., Mich., Wise, and 
N.D., s. to N.M. and Calif. 

3. Puccinellia Nuttalliana (Schult.) Hitchc. 

Perennial; culms usually erect, slender, rather stiff and firm at base, mostly 
3-6 (-10) dm. tall; blades 1-3 mm. wide, flat or becoming involute; panicle 
pyramidal, open, mostly 1-2 dm. long, the distant scabrous branches fascicled, 
spreading and naked below, as much as 1 dm. long; spikelets 3- to 6-flowered, 
4-7 mm. long, the florets rather distant, the rachilla often exposed; pedicels 
scabrous; glumes 1.5-2 mm. long; lemmas 2-3 mm. long, rather narrow, some- 
what narrowed into an obtuse apex; anthers about 0.7 mm. long. P. airoides 
(Nutt.) Wats. & Coult. 

In wet usually alkaline soils, in N. M. (San Juan and San Miguel cos.) and 
Ariz. (Apache and Coconino cos.); Wise, to B.C., s. to Kan., N. M., Ariz, and 
Calif. 

5. Glyceria R. Br. Manna-grass 

Perennials, tufted or subrhizomatous, culms simple; ligule a hyaline scale; 
blades flat, thin; panicles open; spikelets turgid or only slightly laterally com- 
pressed, 3- to 14-flowered; all flowers perfect or the terminal one usually abortive 
or rudimentary; glumes scarious to hyaline, the first usually shorter, acutish and 
1 -nerved, the second obtuse, almost equaling the lowest lemma and obscurely 
3-nerved; rachilla eventually abscising at the lower part of each node; lemmas 
firm to membranous, green, broadly ovate or obovate, usually blunt and scarious- 
margined apically, usually awnless, 7-nerved, the nerves not converging to the 
apex but terminating severally near the distal margin. 

About 40 species, cosmopolitan in distribution. 

1. Spikelets linear, nearly terete, usually 1 cm. long or more, appressed on short 
pedicels; panicles narrow, erect (2) 

1. Spikelets ovate to oblong, more or less compressed, usually not more than 

5 mm. long; panicles usually nodding (4) 

2(1). Lemmas glabrous between the slightly scabrous nerves 1. G. borealis. 

2. Lemmas scaberulous or hirtellous between the usually distinctly scabrous 

nerves (3) 

3(2). Lemmas about 3 mm. long, broadly rounded at the apex.. ..2, G. arkansana. 

3. Lemmas about 4 mm. long, slightly narrowed at apex 3. G. septentrionalis. 

181 




Fig. 81: 
& Chase). 



Glyceria striata: plant, X V^; spikelet, X 5; floret, X 10. (From Hitchcock 



4(1). Lemmas with 5 prominent nerves; second glume 3-nerved; sheaths open 
7. G. pauci flora. 

4. Lemmas with 7 usually prominent nerves; second glume 1 -nerved; sheaths (at 

least the upper) closed from below the summit (5) 

5(4). First glume more than 1 mm. long, usually about L5 mm. long 

6. G. grandis. 

5. First glume not more than 1 mm. long (6) 

6(5). Blades 2-4 mm. wide, sometimes to 8 mm., rather firm, often folded; first 
glume 0.5 mm. long 4. G. striata. 

6. Blades 6-12 mm. wide, flat, thin, lax; first glume about 1 mm. long 

5. G. elata. 

1. Glyceria borealis (Nash) Batchelder. Northern manna-grass. Fig. 80. 
Culms erect or decumbent and rooting at the base, slender, 3-10 dm. tall; 

sheaths smooth or slightly scabrous, keeled; blades flat or folded, usually 2-6 mm. 
wide, very narrow; panicle mostly 2-4 dm. long, very narrow, the branches as 
much as 1 dm. long, bearing several closely appressed spikelets; spikelets mostly 
6- to 12-flowered, 1-1.5 cm. long; glumes oblong, scarious, the first glume 1.5-2 
mm. long, the second 3-4 mm. long; lemmas rather thin, obtuse, 3-4 mm. long, 
strongly 7-nerved, broadly scarious at the tip, minutely scabrous on the nerves, 
otherwise glabrous. 

Shallow water in wet meadows or lake margins, in N. M. {Hitchcock) and 
Ariz. (Coconino, Apache, Cochise and Pima cos.); Nfld. to Alas., s. to Pa., 111., 
Minn, and Wash., in mts. to N. M., Ariz, and Calif. 

2. Glyceria arkansana Fern. 

Tufted perennial; culms stout, 10-15 dm. long, erect; panicles 35-50 cm. long, 
with a number of ascending floriferous branches 0.4—1 mm. thick, rather rigidly 
straight; spikelets 10- to 14-flowered, nearly sessile, appressed, remote; lemmas 
2.5-3.5 mm. long, minutely pubescent. Probably only a form of G. septentrionalis. 

In marshy areas, roadside ditches, along sloughs and in swampy ground, in 
Okla. (McCurtain Co.) and possibly Tex., spring-summer; also La. and Ark. 

3. Glyceria septentrionalis Hitchc. 

Like G. arkansana but lemmas merely minutely scabrous and 3.5-5 mm. long. 
In shallow water and borders of sloughs and lakes and in marshy areas and road- 
side ditches in e. and s.e. Tex., spring-summer; e. N.A. w. to Wise, la., Mo., 
Ark. and Tex. 

4. Glyceria striata (Lam.) Hitchc. Fowl manna-grass. Fig. 81. 

Perennial forming mats by means of short rhizomes; panicles 1-2 dm. long, 
with numerous slender ascending-diverging branches about 0.2 mm. thick (in 
turn bearing even more slender floriferous branchlets); pedicels 0.5-1 mm. long, 
appressed; spikelets 3- to 7-flowered, ovate in outline; lemmas 1.5-2.1 mm. long. 

Rare at the margins of clear permanent streams in limestone areas, in wet 
meadows, bogs and shallow water of ponds and lakes, drainage ditches and 
sloughs in Okla. (Johnston and Murray cos.) and in the Tex. Trans-Pecos 
(Guadalupe Mts.) and e. part of Edwards Plateau, N.M. (Otero, Taos, San 
Miguel and Sandoval cos.) and Ariz. (Coconino, Apache, Navajo and Gila cos.), 
spring-summer; most of the temp, parts of N. A. 

5. Glyceria elata (Nash) Hitchc. 

Culms erect, smooth, succulent, dark green, 1-2 m. tall; sheaths scabrous; 
blades flat, usually 6-9 mm. or sometimes only 4 mm. wide, scabrous; panicle 
large and diffuse, becoming oblong, 15-30 cm. long, the branches naked below, 
the lower ones usually reflexed at maturity; spikelets 3-5 mm. long, oblong or 

183 




Fig. 82: Glyceria grandis: a, floret, showing palea, X 16; b, spikelets, solitary 
on tips of branchlets, X 8; c, habit, lower part showing the conspicuous joints of culm 
and the long lax leaf blades, X %; d, habit, upper part of culm, showing panicle, 
X %; e, leaf sheath, blade and ruptured ligule, X 4; f, floret, showing lemma, the strong 
nerves papillose, X 16; g, young upper leaf, the sheath and ligule enclosing culm, X 4. 
(From Mason, Fig. 67). 



jvate-oblong, usually 6- to 8-flowered; glumes broad, obtuse, much shorter than 
the lower lemmas, often nerveless, the first glume about 1 mm. long, the second 
nearly 2 mm. long; lemmas firm, 2-2.5 mm. long, obovoid, obtuse or acutish, 
prominently 7-nerved, the apex distinctly scarious; stamens 2; palea apex with a 
narrow slit. 

In wet meadows, swampy woods or along streams, in N.M. (Lincoln Co.) and 
Ariz. (Apache, Coconino, Graham, Cochise and Pima cos.); Mont, to B.C., s. 
in mts. to N. M., Ariz, and Calif. 

6. Glyceria grandis Wats, ex Gray. American manna-grass. Fig. 82. 

Culms stout, 1-1.5 m. tall from a perennial base; leaf blades flat, 6-12 mm. 
wide; panicle large, compound, 20—40 cm. long, somewhat nodding at tip; spike- 
lets 4- to 7-flowered, 5-6 mm. long; glumes 1.5-2 mm. long; lemmas purplish, 
2-2.5 mm. long; palea slightly longer than lemma. 

Marshes, stream banks, wet meadows, and in mud and shallow water of ponds, 
lakes and slow-flowing streams, in N. M. (Colfax, San Miguel and Taos cos.) 
and Ariz. (Apache and Graham cos.); P.E.I, to Alas., s. to Va., Tenn., la.. Neb., 
N.M., Ariz, and Ore. 

7. Glyceria pauciflora Presl. Weak manna-grass. Fig. 83. 

Culms 3-12 dm. tall, from a decumbent rooting base; sheaths smooth or 
minutely scabrous, free and overlapping; blades thin, flat, lax, minutely scabrous, 
mostly 8-20 cm. long, 5-15 mm. wide; panicle oblong or pyramidal, open or 
rather dense and spikelike, nodding, 8-20 (or -25) cm. long, the branches ascend- 
ing or spreading, rather flexuous, naked below, the spikelets crowded on the 
upper half; spikelets 4- to 7-flowered (usually 5~ or 6-flowered), 4—6 mm. long; 
glumes broadly ovate or oval, purplish-tinged, the first glume 1-1.5 mm. long, 
the second glume 1.5-2 mm. long, 3-nerved, the nerves sometimes obscure, the 
margins erose-scarious; lemmas oblong, 2-3 mm. (usually 2.5 mm.) long, with 
5 prominent nerves and an outer short faint pair near the margins, minutely 
scabrous on the nerves and somewhat so between ifiim, the tip rounded, scarious, 
somewhat erose, usually with a purplish band below the scarious tip; caryopsis 
with a sub-basal and oblong hilum. Torreyochloa pauciflora (Presl) Church, 
Puccinellia pauciflora (Presl) Munz. 

Marshes, shallow water, and wet meadows, in N.M. (Sandoval and Taos cos.); 
Alas, to S.D., N.M. and Calif. 

6. Poa L. Bluegrass 

Inflorescence paniculate; spikelets 2- to several-flowered, laterally compressed, 
all the flowers functional except usually the terminal one reduced, in some species 
the flowers unisexual and in some the male and female flowers on separate plants 
(at least in some populations); rachilla abscising above the glumes and at the lower 
part of each node; glumes usually shorter than first lemma, thin (marginally often 
hyaline), keeled, the first usually 1-nerved, the second 3-nerved; lemmas keeled, 
ovate-lanceolate, awnless, thin (marginally often hyaline), 5-nerved (or often 
appearing only 3-nerved, one pair of nerves being obscure). 

A genus of about 300 species in cool and temperate regions of the world. 

1. Rhizomes present, often very extensively developed (2) 

1. Rhizomes lacking although plants sometimes stoloniferous (8) 

2(1). Culms strongly flattened, 2-edged; plants strongly rhizomatous; lemmas 
sparsely if at all webbed 1. P. compressa. 

2. Culms slightly if at all flattened, not 2-edged; plants often either only weakly 

rhizomatous or with strongly webbed lemmas (3) 

185 




Fig. 83: Glyceria pauciflora: a, leaf sheath, blade and ligule, X 2; b, upper part 
of culm, showing panicle, X Vr,; c, branch of panicle, the spikelets crowded on the 
upper half, X 6; d, panicle, X %; e, floret, showing palea and rachilla, X 12; f, floret, 
showing lemma, X 12; g, grain, showing subbasal oblong hilum, X 20; h, habit, lower 
part of culm, showing the flat, lax leaf blades, X %. (From Mason, Fig. 66). 



3(2). Panicle narrow, the branches ascending or appressed; lemmas scabrous to 
pubescent on all the nerves but not webbed 3. P. glaucifolia. 

3. Panicle open, the branches mostly spreading; lemmas often webbed at base 

or glabrous on the internerves (4) 

4(3). Plants alpine or subalpine; lemmas pubescent over the back and silky on 
the 5 nerves, usually webbed 4. P. Grayana. 

4. Plants often of lower elevations; lemmas sometimes glabrous on the internerves 

or not webbed (5) 

5(4). Anthers mostly 0.5-0.9 mm. long; lower panicle branches mostly in twos 
6. P. leptocoma. 

5. Anthers at least 1 mm. long; lower panicle branches usually in threes or fives 

(6) 

6(5). Lemmas not webbed at base 3. P. glaucifolia. 

6. Lemmas more or less strongly webbed at base (7) 

7(6). Ligules mostly not over 1.5 mm. long, rarely with the uppermost much 
longer, truncate; lemmas more than 3 mm. long 2. P. pratensis. 

7. Ligules mostly (2-) 3-5 mm. long, often acute; lemmas 2.5-3 mm. long 

7. P. palustris. 

8(1). Lemmas with long tangled cobwebby hairs at base (9) 

8. Lemmas not cobwebby at base (13) 

9(8). Panicle loose, the lower slender branches 1 to 3 per node and spreading 
or reflexed; spikelets usually purplish; ligules glabrous, usually over 
1 mm. long; anthers not over 1 mm. long (10) 

9. Panicle very narrow, the branches ascending or more than 3 per node; spike- 

lets usually greenish; ligules often puberulent-scabridulous, some- 
times less than 1 mm. long; anthers often over 1 mm. long (11) 

10(9). Lower panicle branches reflexed, 1 to 3 per node 5. P. reflexa. 

10. Lower panicle branches usually not reflexed, generally in pairs 

6. P. leptocoma. 

11(9). Spikelets averaging about 6 mm. long, the lemmas 4-5 mm. long 

4. P. Grayana. 

11. Spikelets usually less than 5 mm. long, the lemmas less than 4 mm. long (12) 

12(11). Plants of the lowlands or low mountains; culms decumbent and usually 

stoloniferous, 4-12 dm. tall; ligules (2-) 3-5 mm. long 

7. P. palustris. 

12. Plants montane to subalpine; culms erect, not at all stoloniferous; ligules 

rarely as much as 2 mm. and never so much as 3 mm. long 

8. P. interior. 

13(8). Spikelets compressed, at anthesis usually less than twice as long as broad; 
lemmas rather strongly keeled (14) 

13. Spikelets only slightly compressed, at anthesis over twice as long as broad; 

lemmas rounded on the back or only slightly keeled (15) 

14(13). Ligules usually truncate, 0.3-1 (or rarely to 2) mm. long; spikelets 

mostly 2- to 3- (4-) flowered; second glume 2.5-3.5 mm. long 

8. P. interior. 

14. Ligules usually obtuse to acute, generally at least 1 (the longest 4) mm. 

long; spikelets mostly 3- to 5-flowered; second glume rarely less 
than 4 mm. long 4. P. Grayana. 

15(13). Ligules thickish, strongly ciliolate, truncate to roundish, those of the 
innovations and basal culm leaves scarcely visible from the side, 
mostly not over 0.5 (to 1 ) mm. long, those of the upper culm 
leaves mostly 1-1.5 (rarely to 2.5 mm.) long 10. P. juncifolia. 

187 




Fig. 84: /Poa pratensis: plant, X i^; spikelet, X 5; floret, X 10. (From Hitchcock & 
Chase). 



15. Ligules thin and membranous, rarely ciliolate, usually acute, those of the 
innovations and lower culm leaves usually over 1 mm. long, those 
of the upper culm leaves mostly 2-7 mm. long 9. P. nevadensis. 

1. Poa compressa L. Canada bluegrass. 

Perennial; culms basally long-decumbent, stoloniform or subrhizomatous, 
strongly compressed, 1-2.5 mm. broad, with 2 longitudinal keels; aerial culms 
ascending, somewhat geniculate; lower sheaths shorter than the internodes; blades 
3-12 cm. long, 1-3 mm. broad, flat or folded; panicles conic-cylindric, 3-10 cm. 
long, open with few short branches per whorl rather strikingly ascending; pedicels 
5-10 mm. long; spikelets crowded, laterally compressed, 3- to 6-flowered; lowest 
lemma 2-3 mm. long, firm, green-stramineous, keeled, 5-nerved, the lower part 
of the midnerve and marginal nerves minutely pubescent, the very obscure inter- 
mediate nerves and internerve areas glabrous, basally with very short scant tuft 
of silky hair or this absent. 

Tame pastures, wet meadows and in marshy soil, in Okla. (Waterfall) and 
n.-cen. Tex. and the Rio Grande Plains, probably elsewhere, not persistent but 
repeatedly introd., N.M. (Taos, San Miguel and Colfax cos.) and Ariz. (Apache, 
Navajo, Coconino, Graham and Gila cos.), spring; nat. of Eur., now widely 
introd. in Am. 

2. Poa pratensis L. Kentucky bluegrass. Fig. 84. 

Tufted perennial with fragile rhizomes 1-2 mm. thick and to 2 dm. long; 
aerial culms 3-6 dm. long, mostly erect, slightly flattened but not two-keeled; 
ligule a short usually erose scale; blades thin, 2-4 mm. broad, flat or folded, 
basally not markedly broader than the top of the sheath; panicles 5-13 cm. long, 
conical, usually open and with a whorl of 5 flexuous basally naked branches at 
the lowest node, the successively higher nodes with fewer branches; pedicels 
0.5-1.5 mm. long; spikelets somewhat laterally compressed, crowded, 4- to 
6-flowered; lowest lemma 3-4 mm. long, green with a broad thin whitish margin, 
dorsally keeled, 5-nerved, the lower part of the midnerve and marginal nerves 
pubescent, the intermediate nerves and internerve area glabrous, basally with a 
long tuft of flexuous silky hairs. 

Meadows and tame pastures, and in wet soil on edge of lakes and ponds, in 
n.-cen., e. and Trans-Pecos Tex., infrequent and probably not persistent, N. M. 
(Sandoval Co.) and Ariz. (Apache to Mohave, s. to Cochise, Santa Cruz and Pima 
COS.), spring; nat. of Euras., now widely introd. in moist temp, areas of N.A. and 
S.A. 

3. Poa glaucifolia Scribn. & Williams. 

Plants glaucous; culms in loose tufts, 6-10 dm. tall; blades 2-3 mm. wide; 
panicle narrow, open, mostly 1-2 dm. long, the branches usually in somewhat 
distant whorls, mostly in threes, ascending, very scabrous, naked below; spikelets 
2- to 4-flowered; glumes 4-5 mm. long; lemmas about 4 mm. long, villous on 
the lower half of the keel and marginal nerves and more or less so on the inter- 
mediate nerves below. 

In wet meadows, ditches and stream bottoms, in N.M. (Hitchcock) and Ariz. 
(Coconino Co.), July-Aug.; B.C. and Alta. to Minn., Neb., N.M., Ariz, and Nev. 

4. Poa Grayana Vasey Arctic bluegrass. 

Culms loosely tufted, erect from a decumbent base, 1-3 dm. tall; ligule pointed, 
to 4 mm. long; blades mostly basal, flat or folded, mostly 2-3 mm. wide, with 
one short blade about the middle of the culm; panicle open, pyramidal, 5-10 cm. 
long, the lower branches usually 2 and spreading or sometimes reflexed, bearing 
a few spikelets toward the tip; spikelets 5-8 mm. long, 3- or 4-flowered; lemmas 
densely villous on the keel and marginal nerves and pubescent on the lower part 

189 



of the internerves, the base often webbed. P. arctica of Am. Auth., not R. Br. 

In wet meadows, shallow water of lakes and ponds, and on wet stream banks, 
mostly above timberline, in N. M. (Rio and Taos cos.); from arctic regions s. 
to N.S. and in the Rocky Mts. to N.M., Nev. and Calif. 

5. Poa reflexa Vasey & Scribn. Nodding bluegrass. 

Culms solitary or in small tufts, erect, 2-4 dm. tall; blades rather short, 1-4 
mm. wide; panicle nodding, 5-15 cm. long, the branches naked below, solitary, 
in pairs or in threes, the lower usually reflexed, sometimes strongly so; spikelets 
2- to 4-flowered; lemmas about 3 mm. long, oblong-elliptic, webbed at base, villous 
on keel and marginal nerves and sometimes on intermediate nerves. 

In wet meadows and on wet stream banks, in N. M. (Santa Fe Co.) and 
Ariz. (Coconino Co.); Mont, to e. B.C., s. in mts. to N.M. and Ariz. 

6. Poa leptocoma Trin. Bog bluegrass. 

Culms slender, solitary or few in a tuft, 2-5 dm. tall, often decumbent at 
the base; sheaths usually slightly scabrous; ligule acute, the uppermost 3-4 mm. 
long; blades short, lax, mostly 2-4 mm. wide; panicle nodding, delicate, few- 
flowered, the branches capillary and ascending or spreading, subflexuous, the 
lower mostly in pairs; spikelets narrow, 2- to 4-flowered; glumes narrow, acumi- 
nate; lemmas 3.5-4.5 mm. long, acuminate, webbed at base, pubescent on the 
keel and marginal nerves or sometimes nearly glabrous, the intermediate nerves 
distinct. 

In bogs and wet meadows and wet places along streams, in N.M. {Hitchcock); 
Alas., s. in mts. to N.M. and Calif. 

7. Poa palustris L. Fowl bluegrass. 

Culms loosely tufted, glabrous, decumbent at the flattened purplish base, 3-15 
dm. tall; sheaths keeled, sometimes scaberulous; ligule 3-5 mm. long or only 1 
mm. on the innovations; blades 1-2 mm. wide; panicle pyramidal or oblong, 
nodding, yellowish green or purplish, 1-3 dm. long, the branches in rather distant 
fascicles, naked below; spikelets 2- to 4-flowered, about 4 mm. long; glumes 
lanceolate, acute, shorter than the first floret; lemmas 2.5-3 mm. long, usually 
bronzed at the tip, webbed at base, villous on the keel and marginal nerves. 

Wet meadows and wet open soils, in N.M. (Hiichcook) and Ariz. (Graham 
Co.); Nfld. and Que. to Alas., s. to Va., Mo., Neb., N.M., Ariz, and Calif.; 
Euras. 

8. Poa interior Rydb. 

Tightly tufted perennial; culms numerous, 2-5 dm. long, about 1 mm. thick, 
strictly erect; blades short, about 1 mm. broad, flat, erect; panicles 4-8 cm. 
long, 1-2 cm. broad, rather dense, almost spiciform, strictly erect, the lower 
node with 2 (rarely 3) strictly erect basally naked branches; spikelets crowded, 
laterally compressed, 2- to 4-flowered; lowest lemmas 3-4 mm. long, keeled, 
stramineous, firm, 5-nerved, the midnerve and marginal nerves pubescent at least 
in the lower part, the intermediate nerves very obscure, the internerve areas 
glabrous, the base with a weak tuft of long flexuous silky white hair. 

In water of streams, edge of lakes and ponds, and in marshes, in N.M. (San- 
doval and Taos cos.) and Ariz. (Coconino Co.), reported to occur in Tex.; if 
present then rare at highest elev. in the Trans-Pecos mts.. summer; forested mt. 
slopes. Que. to B.C. and s. in the mts. to Ariz, and N.M. 

9. Poa nevadensis Vasey ex Scribn. Nevada bluegrass. 

Culms erect, 5-10 dm. tall; sheaths scabrous, sometimes only slightly so; 
ligule about 4 mm. long, shorter on the innovations, decurrent; blades usually 
elongate, narrow, involute, sometimes almost capillary, rather stiff; panicle narrow, 

190 




Fig. 85: Briza minor, plant, X 1/2; spikelet and floret, X 5. (From Hitchcock & 
Chase). 



10-15 cm. long, pale, rather loose, the branches short-appressed; spikelets 3- to 
5-flowered, 6-8 mm. long; glumes narrow, the second about as long as the lowest 
floret; lemmas 4-5 mm. long, rather obtuse at the scarious tip. 

Low meadows and other such wet places, in Ariz. (Kearney & Peebles) ; Mont, 
to Wash, and Yuk., s. to Colo., Ariz, and Calif. 

10. Poa juncifolia Scribn. 

Strongly tufted perennial sometimes producing rhizomes, 4-12 dm. tall; sheaths 
smooth to scaberulous, rarely closed as much as one fourth their length; innova- 
tions usually numerous, their blades often 1-3 cm. long, from involute and 
almost filiform to flat and as much as 3 mm. wide; culm leaves usually shorter 
than those of the innovations; ligules rather thick, truncate to rounded, strongly 
scaberulous-puberulent and finely ciliolate, from 0.5 mm. long on the innovations 
to as much as 2 or 3 mm. long on the upper culm leaves; panicle narrow, 
usually 6-20 cm. long, the branches mostly erect; spikelets 3- to 7-flowered, (5-) 
7-10 mm. long; glumes slightly unequal, usually 3-nerved, the first mostly 3.5-4.5 
mm. long, the second 4—5 mm. long; lemmas slightly keeled, 4-6 mm. long, 
without a basal web and usually either finely scaberulous over the back or glabrous 
over the lower half, sometimes scabrous above and very finely crisp-puberulent 
on the lower fourth; anthers 2-3 mm. long; lodicules about 0.7 mm. long. P. 
ampla Merrill. 

In marshes, wet alkaline meadows and rocky open slopes, in N.M. [Hitchcock) 
and Ariz. (Santa Cruz Co.); Alta., Neb., the Dakotas to B.C., s. to N.M. and 
Calif. 

7. Briza L. Quaking Grass 

A genus of 20 species in temperate North America and South America; we 
have only a single species. Another species, B. maxima L., the big quaking grass, 
is occasionally cultivated but does not persist or escape. 

1. Briza minor L. Little quaking grass. Fig. 85. 

Annual; culms 1-4 dm. long, erect or at the very base shortly decumbent; 
ligule a long hyaline scale sheath shorter than the internodes, having an inverted 
V-shaped juncture to the blade; blades 5-10 mm. broad, flat; panicle broadly 
ovoid, 5-12 cm. long, about as broad, open, diffuse, with ascending-spreading 
branches that are twice trichotomous and naked; spikelets pendulous from the 
ultimate capillary pedicels at the periphery of the panicle, 3-5 mm. long, 6- to 
8-flowered, broader than long, markedly tapered, only very slightly laterally com- 
pressed; glumes 2, very broad, spreading, 3-nerved, with broad hyaline margins; 
lemmas 1.5-2 mm. long, spreading cymbiform, 5-nerved, marginally broadly 
hyaline, basally auriculate and thus basally overlapping each other; rachilla 
abscising above the glumes and at the lower part of each node. 

Infrequent in swales and in woods or open sandy soil, in marshes, wet meadows 
and seepage areas, in e. and s.e. Tex., spring; nat. of Eur., widely introd. in 
the U.S. 

8. Eragrostis Beauv. Lovegrass 

Variable in habit and foliage; panicles usually much-branched (the branches 
in some species very short and closely appressed); spikelets usually somewhat 
laterally compressed, several-flowered; glumes shorter than the lowest lemma, 
1-nerved; lemmas 3-nerved (lateral nerves sometimes obscure); rachilla either 
remaining intact (lemmas then deciduous) or abscising above the glumes and 
either at the upper or lower part of each lemma-node or breaking irregularly 
between the florets under mechanical pressure during tumbling of the panicle. 

192 




Fig. 86: Eragrostis hypnoides: a, habit, showing slender creeping culms, divergent 
leaf blades and elliptic panicles, X %; b, spikelet, showing hairs on backs of glumes and 
lemmas, X 8; c, mature seed, X 40; d, floret, X 20; e, leaf sheaths and blades, X 8. 
(From Mason, Fig. 65). 



A genus of about 300 species widely distributed in warm regions. Some love- 
grasses are difficult to determine, the characters useful in distinguishing them 
being subtle, quantitative ones which tend to grade from one species to another. 
This probably is evidence of past hybridization and genetic contamination of 
many species. 

1. Mat-forming annuals creeping by stolons (2) 

1. Not mat-forming (3) 

2(1). Flowers unisexual, staminate ones on some plants, pistillate on others; 
lemmas about 3 mm. long, persistent on the rachilla....!. E. reptans. 

2. Flowers perfect; lemmas 1.5-2 mm. long, falling individually from the rachilla 

to expose the minute paleas which persist on the rachilla 

2. E. hypnoides. 

3(1). Spikelets (the lateral ones, not those terminal on the panicle branches) 
subsessile, their pedicels averaging less than 1 mm. long (4) 

3. Spikelets (the lateral ones) with pedicels averaging more than 1 mm. long, 

often much more (5) 

4(3). Lemmas about 1 mm. long 8. E. glomerata. 

4. Lemmas 1.5-5.5 mm. long 4. E. cilianensis. 

5(3). Pedicels of individual spikelets 10-30 mm. long, averaging about 15-20 
mm. long, rather stiff and straight 7. E. Elliottii. 

5. Pedicels of individual spikelets 1-18 mm. long, averaging usually less than 

10 mm. long, stiffish to weak and flexible (6) 

6(5). Perennial 6. E. hirsuta. 

6. Annuals (7) 

7(6). Lemmas about 1 mm. long 3. E. pilosa. 

7. Lemmas 1.5-2.5 mm. long 5. E. pectinacea. 

1. Eragrostis reptans (Michx.) Nees. 

Mat-forming annual, extensively creeping by stolons, rooting at the numerous 
nodes; sheaths about 5 mm. long; blades 1-4 cm. long; panicles 1-3 cm. long, 
about as thick, of several glomerules of spikelets, often subcapitate, of 2 sexes, 
the staminate panicles on some plants, the pistillate on others; spikelets laterally 
compressed, curvilinear, 4-17 mm. long, 6- to 32-flowered, the rachilla remaining 
intact; lemmas often pubescent, about 3 mm. long, not falling individually from 
the rachilla. Neeragrostis reptans (Michx.) Nicora. 

Locally abundant in swales and lake- and river-beds, and muddy shores of 
lakes, streams and ponds, usually in tight clay-loam soil, in Okla. {Waterfall) 
and in n.-cen., e. and s.e. Tex. and Rio Grande Plains, spring-fall; cen. U. S. 
from S.D. e. to 111. and Ky. and s. to Coah. and Tam.; also Fla. 

2. Eragrostis hypnoides (Lam.)B.S.P. Fig. 86. 

Annual, creeping over small areas by short stolons; culms very slender and 
short; sheaths and blades very short as in E. reptans; panicles often subcapitate 
or occasionally elongate to interrupted-spikelike or even more open, diffusely 
oblong, with short branches; pedicels 1-3 mm. long, capillary, somewhat flexuous; 
spikelets approximate or even glomerulate, linear, 2-20 mm. long, 4- to 44- 
flowered, the flowers all perfect, the rachilla remaining intact; lemmas lance- 
ovate, 1.5-2 mm. long, falling individually (starting at the bottom of the spikelet) 
to liberate the grains and to leave the minute paleas persistent on the rachilla. 

Locally abundant in swales, borrow ditches, on margin of ponds, sloughs and 
streams, and on mud flats, streambars and banks, in Okla. (Pittsburg Co.), e. 
and s.e. Tex., rare in coastal parts of Rio Grande Plains (Cameron Co.) and 
N.M. (Taos Co.), spring-fall; widespread from s. Can. nearly throughout the 
U.S. to Mex. and W.L; Arg. 

194 




Fig. 87: Eragrostis cilianensis: plant, X 1/2; spikelet, X 5; floret, X 10. (From Hitch- 
cock & Chase). 



3. Eragrostis pilosa (L.) Beauv. India lovegrass. 

Loosely tufted annual; culms 1-5 dm. long, very slender, pronouncedly genicu- 
late and sparingly or not branched near the base; sheaths much shorter than the 
internodes, mostly glabrous except at the corners; blades short, 1-3 mm. broad, 
often flat; panicles mostly pyramidal, long-exserted, very diffuse, 5—20 cm. long, 
with a few widely spreading capillary branches which in turn bear the capillary 
pedicellary branchlets that are mostly deflexed and 3-8 mm. long; spikelets linear, 
3-6 mm. long, about 1 mm. broad, 3- to 10-flowered; lemmas about 1 mm. long, 
gray with dark purple tip, falling individually from the slightly fractiflex intact 
rachilla. 

On muddy or wet sandy banks along streams and wet meadows, a rare weed 
in Okla. (LeFIore Co.) and n.-cen. and e. Tex., summer; nat. of s. Eur., now 
scattered in warmer parts of the New World. 

4. Eragrostis cilianensis (All.) E. Mosher. Stinkgrass. Fig. 87. 

Loosely tufted annual, odoriferous when fresh; culms 5-50 cm. long, mostly 
decumbent and geniculate basally, ascending distally, rarely branched, with an 
obscure yellow glandular (often broken) ring shortly below each node; sheaths 
mostly shorter than their internodes and often pilose -on the corners, with micro- 
scopic glands along the keel and near the base also along the nerves; blades 3-7 
mm. broad, mostly flat, often papillose-pilose along the margins basally; panicles 
3-20 cm. long, 1-7 cm. broad, narrowly oblong or ovoid, rather dense (spikelets 
touching), with a number of short ascending branches (glabrous in the axils) 
bearing in turn the glomerules of spikelets on individual pedicels 0.5-1 mm. long, 
the branches and pedicels often gland-dotted; spikelets 8- to 40-flowered, 5-15 
mm. long, slightly tapering; lemmas 2-2.8 mm. long, membranous, suborbicular, 
with conspicuous lateral veins and rounded apex, falling individually from the 
intact rachilla, the keel scabrous and with a few glands toward the apex. E. 
megastachya (Koel.) Link. 

Edge of playa lakes and pond margins, in wettish sandy alkali among Tamarix, 
in Okla. (Alfalfa Co.) and in the Tex. Trans-Pecos and Plains Country, infre- 
quent e. to n.-cen. Tex. and Rio Grande Plains, rare in s.e. Tex. to Ariz, 
(rather wide-spread), spring-fall; nearly throughout the warmer parts of the 
world, introd. from the Old World. 

5. Eragrostis pectinacea (Michx.) Nees. 

Loosely tufted diffuse annual; culms numerous, 15-30 cm. long, ascending or 
usually spreading and geniculate in the lower part where also sparingly branched; 
sheaths usually folded, softly keeled, pilose at the corners; blades 2-5 mm. broad, 
mostly flat; panicles ascending or often nodding or even altogether inclined, 
obovoid, usually open and diffuse when mature, 5-40 cm. long, with numerous 
ascending branches bearing along the distal two-thirds of their length the ap- 
pressed flexuous pedicellary branchlets (1-5 mm. long) or in larger specimens 
the lower main branches with ascending secondary branchlets that in turn bear 
the appressed pedicellary branchlets; spikelets mostly appressed or nearly so, 
slightly tapered, plumbeous, 3-10 mm. long; lemmas 1.5-2 mm. long, blunt, 
all plumbeous, eventually falling from the intact rachilla (the lowest lemma falling 
first). E. diffusa Buckl., E. perplexa L. H. Harvey. 

Frequent in a variety of habitats, most abundant in disturbed loamy soil near 
roads, fields and streams, in water and mud on edge of streams, p>onds and 
lakes, in Okla. (Mayes Co.) and throughout Tex., spring-fall; essentially through- 
out the U.S. and s. into Mex. 

6. Eragrostis hirsuta (Michx.) Nees. 

Tightly tufted perennial; culms 4-10 dm. long, erect, unbranched; sheaths 

196 




Fig. 88: Monanthochloe Uttoralis: a, habit, staminate plant, X %; b, staminate in- 
florescence, X 5; c, leaf and sheath, X 5; d, habit, pistillate plant, X %; e, plant later 
in the season after flowering, X V-y; f, pistillate inflorescence, X 5; g, leaf and sheath 
of plant after flowering, X 5. (V.F.). 



much longer than their internodes, shortly ascending-pilose in the upper part 
and long erect-pilose at the apex dorsally, or rarely nearly glabrous; blades 
elongate-arcuate, the upper ones nearly surpassing the panicle, folded or eventually 
involute, 5-10 mm. broad when flattened; panicle 2-6 dm. long, 8-30 cm. broad, 
open and diffuse, of numerous usually slightly to markedly ascending branches 
bearing several secondary branches (these often deflexed) which in turn bear the 
long capillary spreading pedicels (8-18 mm. long); spikelets 2-4 mm. long, 
markedly tapered, (1- or) 2- to 4-flowered; lemmas 1.7-2.2 mm. long, ovate, 
blunt, with obscure lateral nerves, falling individually from the intact rachilla. 

In marshy areas, alluvial areas, and in open sandy woods, in Okla. (Nowata 
Co.) and in e. and s.e. Tex., s.w. to San Patricio Co., summer-fall; Coastal 
States, Me. to Tex. and inland to Tenn., Ark. and Okla.; Br. Hond. 

7. Eragrostis Elliottii Wats. 

Tufted perennial (not knotty basally); culms 4-8 dm. long, erect; ligule a 
minute lacerate-f ringed scale; sheaths long, shortly pilose at the corners, otherwise 
glabrous; blades rolled up marginally, stiffly ascending to a very slender tip; 
panicles erect, 25-50 cm. long, nearly as broad as long, very diffuse, with 
numerous long stiff antrorsely scabrous capillary branches that in turn bear long 
straight mostly deflexed capillary pedicellary branchlets 1-3 cm. long (these 
bearing spikelets only at the end, not along the length); part of the panicle often 
included in the uppermost sheath; spikelets strongly laterally compressed, remote, 
linear, 5-12 mm. long, mostly 8- to 15-flowered, about 1.5 mm. broad; lemmas 
ovate, about 1.5 mm. long, not falling away individually but the rachilla of the 
spikelet eventually breaking up by mechanical action. 

Rare in wet sandy open woods, wet meadows and low grounds, in extreme 
s.e. Tex. near the coast, summer-fall; Coastal States, from N.C. to Tex.; W.I., 
Mex.; Br. Hond. 

8. Eragrostis glomerata (Walt.) L. H. Dewey. 

Annual; cuims 2-10 dm. long, erect, sparingly branched and geniculate in 
the lower third; panicles erect or slightly nodding, 5-50 cm. long, only \—4 cm. 
broad, with numerous long main branches and these in turn further branched, all 
the branches strictly ascending; spikelets nearly sessile, 2-3 mm. long, 6- to 8- 
flowered; lemmas about 1 mm. long; palea glabrous or merely scabrous on the 
keels; rachilla eventually abscising above the glumes and between the florets. 

Rare in roadside ditches, on wet banks of ponds, streams and lakes, in Okla. 
(LeFlore Co.) and in e. Tex., summer-fall; widespread in warmer parts of the 
New World n. to S.C. and the Gulf States; also waifed n. to Mo. 

9. Monanthochloe Engelm. 
A monotypic North American genus. 

1. Monanthochloe littoralis Engelm. Fig. 88. 

Perennial forming extensive mats by rhizomes and/or stolons; flowering culms 
ascending, 5-25 cm. long; branches of 2 size-classes; few-noded elongate culms 
with leaves 10-15 cm. long, bearing in the axils many-noded short shoots with 
crowded leaves 5-10 mm. long; sheaths and blades extremely short, very firm, 
indurate-wiry, folded-falcate, grayish-green; male and female flowers on separate 
plants; panicles reduced to solitary 3- to 5-flowered spikelets, appearing terminal 
and embedded in the masses of leaves of the short shoots, difficult to find; 
glumes apparently absent; lemmas coriaceous or in the pistillate spikelet like the 
leaves; upper florets rudimentary; rachilla of pistillate floret tardily abscising at 
the lower part of the nodes. 

198 




Fig. 89: Distichlis spicata: a, culm, leaf sheaths and ciliate base of leaf blades, X 4; 
b, habit, pistillate plant, X 2/-; c, pistillate spikelet, X 4; d, staminate spikelet, X 4; e, 
mature grain, hard and nutlike, X 8; f, habit, pistillate plant, X %; g, stammate floret, 
X 8; h, pistillate floret, X 6; i, leaf sheath, base of blade and ciliate ligule, X 6. (From 
Mason, Fig. 61). 



Locally abundant in poorly drained brackish or tidal saline flats or cayos near 
the coast, s.e. Tex. and Rio Grande Plains, also in Gonzales Co., spring; Fla. to 
Cuba; Tex. to Tarn, and Coah.; Calif, to Baja Calif., Son. and Sin. 

10. Distichlis Raf. 

A small American genus of perhaps 3 or 4 species. 
1. Distichlis spicata (L.) Greene. Saltgrass. Fig. 89. 

Perennial, rarely more than 3 dm. tall, forming tight colonies in saline mud 
by means of very tough slender whitish scaly rhizomes; culms erect, 1-3 (-5) 
dm. tall, tough and wiry; leaves usually noticeably 2-ranked, narrow (1-3 mm. 
broad), usually mostly involute, tough, pungent, only 2-6 (-10) cm. long, ascend- 
ing; male and female flowers on separate plants; spikelets rather similar on both 
kinds of plants, in terminal erect spikes or spikelike racemes; pistillate racemes 
often shorter than staminate (the staminate ones often overtopping the foliate); 
spikelets 5- to 15-flowered, usually 6-10 mm. long; rachilla of the pistillate 
spikelets disarticulating above the glumes and between the florets; glumes unequal, 
broad, acute, keeled, 3- to 7-nerved, the lateral nerves sometimes faint; lemmas 
closely imbricate, firm, the coriaceous pistillate ones acute or subacute and 3-6 
mm. long, the pistillate ones more coriaceous and more closely imbricate than 
the staminate, with 9 to 1 1 mostly faint nerves; palea as long as the lemma or 
shorter, the margins bowed out near the base, rather soft, narrow, the keels 
narrowly winged, the pistillate lemmas coriaceous and enclosing the grain which 
is brown. 

Represented with us by two varieties as follows: 

Var. spicata. Culms 1-6 dm. tall, slender, erect; blades erect, to 15 cm. long, 
10-25 mm. apart on the culm, equaling or exceeding the pistillate spikes and 
rarely exceeded by the staminate spikes; pistillate spikes pale green, 1-6 cm. long, 
of 8 to 36 congested spikelets that are 5- to 9-flowered, up to but not exceeding 
1 cm. long, 4 mm. broad; first glume 3 mm. long; second glume 4 mm. long; 
lemmas 6- to 10-nerved, 3.5-4 mm. long, closely imbricate; palea keels minutely 
evenly serrate, the 4 nerves often excurrent; grain about 2 mm. long, somewhat 
truncate at the tip; staminate spikes pale green, 1-6 cm. long, of 6 to 30 
congested spikelets that are 7- to 10-flowered, about 1 cm. long, 4 mm. broad; 
first glume to 3 mm. long; second glume to 4 mm. long; lemmas 6- to 10-nerved, 
3 mm. long; palea 2-keeled but otherwise nerveless, about 3 mm. long. 

Salt marshes near the coast, very abundant, rare in salt marshy areas inland 
in e. Tex., summer-fall; Can. to Mex. along the coast; also W.I. 

Var. stricta (Torr.) Beetle. Culms 10-35 cm. tall, erect or rarely decumbent; 
blades to 2 dm. long, the upper equaling or exceeding the pistillate spikes but 
exceeded by the staminate ones; pistillate spike green drying stramineous-brown, 
2-7 cm. long, of 5 to 40 approximate spikelets that are 5- to 20-flowered, 5-20 
mm. long and 4-7 mm. broad, the mature florets often strongly reflexed, usually 
not closely imbricate; first glume 2-3 mm. long; second glume 3-4 mm. long; 
lemma 2.5-6 mm. long, firm, with a broad hyaline margin; palea 3-5 mm. long, 
the keels conspicuously serrate to the base, often dentate, narrowed or winged at 
base, occasionally with a few long hairs on back; grain 2-5 mm. long, sometimes 
slenderly tapered to a single beak, sometimes truncate with a double beak; 
staminate spike green or rarely purplish, drying stramineous-brown, 2-5 cm. long, 
of 5 to 25 approximate spikelets that are 5- to 20-flowered, 5-20 mm. long 
and 4-7 mm. broad, closely imbricate; first glume 2-3 mm. long; second glume 
3-4 mm. long; lemmas 5-6 mm. long, firm, equalled by the palea; palea 5-6 
mm. long, the keels conspicuously serrate to the base, infrequently dentate, rarely 
broadly winged, usually with at least one prominent marginal vein. D. stricta 
(Torr.) Rydb. 

200 




Fig. 90: Chasmanthium latifolium: plant, X %; spikelet and floret, X 3. (From 
Hitchcock & Chase). 



Locally abundant in alkaline or alkaline-saline areas such as marshes, lakes 
and irrigation ditches, in Okla. (Alfalfa Co.) and w. half of Tex., N. M. (Guada- 
lupe, Sandoval, Chaves and Valencia cos.) and Ariz. (Coconino Co.), summer-fall; 
w. U. S. e. to the Dakotas, Neb., Kan., Okla., Tex., Coah. and Chih. 

11. Chasmanthium Link 

A North American genus of 5 species. 

1. Chasmanthium latifolium (Michx.) Yates. Inland sea oats. Fig. 90. 

Essentially glabrous rhizomatous perennial; rhizomes short, indurated, forming 
mats; culms rising singly from the mats, 5-13 dm. long, 1.5-3 mm. thick, usually 
purplish, reclining and geniculate below, above erect, simple and stramineous, 
terete; sheaths considerably shorter than the internodes and tightly clasping them; 
blades lanceolate, 1-2 dm. long, 8-16 mm. broad, divergent, acute, striate-veined; 
panicles very lax, 15-30 cm. long, of 10 to 30 (to 50) large spikelets drooping 
at the ends of mostly naked capillary branches 3-10 cm. long; spikelets very 
strongly laterally compressed, 12- to 18-flowered, 25-45 mm. long, 13-16 mm. 
broad; rachis of spikelet with zone of abscission at the lower part of each node; 
glumes subequal, 5-7 mm. long, about 1 mm. broad, cymbiform, shorter than 
the lowest lemma; lemmas broadly lanceolate, 9-13 mm. long, 5-7 mm. broad 
when unfolded, apically slightly incurved and acutish, grayish to bluish-green, 
firm, marginally very narrowly hyaline with 3 to 6 nerves on each side, minutely 
scabrellate, on the keels minutely pectinately scabrous; paleas only two thirds as 
long as the lemmas and of the same texture, doubly strongly keeled (the keels 
minutely pectinate), falcate; grain laterally compressed, black, rough, about 3 
mm. long. Uniola latifoUa Michx. 

Locally abundant in moist loamy soils of creek bottoms, in marshes, in mud 
and shallow water of streams and ponds, in Okla. (McCurtain, Washington, 
Murray, Ottawa and Cherokee cos.) and in e. and s.e. Tex., less common w. to 
n.-cen. Tex., e. Edwards Plateau and n. part of Rio Grande Plains, summer-fall; 
most of s.e. U.S., n. to Pa., O., 111. and Neb.; also N. L. 

12. Dactylis L. 

A genus of 5 species indigenous to temperate Eurasia. 

1. Dactylis glomerata L. Orchard grass. Fig. 91. 

Densely tufted perennial; culms geniculate, ascending, 6-10 dm. long; ligule 
a lacerate hyaline scale; sheaths and blades soft, the blades flat and mostly ag- 
gregated toward the base; panicles long-exserted, mostly narrow, erect, with few 
mostly ascending branches, each of which bears apically a very dense aggregation 
(about 1 cm. thick) of secund nearly sessile fascicles of spikelets; spikelets few- 
flowered, laterally compressed; rachilla abscising at the lower part of each node; 
glumes and lemmas keeled, the keels hispid; lemmas 5-nerved, about 7 mm. long, 
narrowly lanceolate, mucronate. 

In stream beds and wet meadows, rare in farm pastures and roadsides in Okla. 
{Waterfall), the Tex. Plains Country (Lubbock Co.) and N. M. (Taos Co.), 
spring-summer; widespread in temp, areas, nat. to Euras. 

13. Arundo L. 

About 8 species in the Old World tropics; we have one. 
1. Arundo Donax L. Giant reed, Georgia cane, carrizo. Fig. 92. 

Canelike grass from thick short rhizomes, forming large clumps; aerial culms 
2-6 m. long, to 5 cm. thick, erect, rarely branched, perennial or in the northern 
extremes mostly freezing down annually or every few years; ligule a short scale; 

202 




Fig. 91: Dactylis glomerata: plant, X V-y, spikelet and floret, X 5. (From Hitchcock 
& Chase). 




Fig. 92: Arundo donax: plant, X i/^; spikelet and floret, X 3. (From Hitchcock & 
& Chase). 



blades mostly 3-6 dm. long, 2-5 cm. broad or larger, often glaucous, firm; 
inflorescence a thick narowly ellipsoid buffy-white panicle 3-6 dm. long; spike- 
lets 13-15 mm. long, usually 3-flowered; rachilla glabrous, with zones of abscis- 
sion at lower part of each node; glumes subequal, cymbiform, thin, nearly as long 
as the spikelet, each 3-nerved; lemmas (including the small calloused base) long- 
pilose, 3-nerved, thin, cymbiform, obscurely round-keeled, long-attenuate to very 
fine points. 

Established along irrigation ditches and streams (occasional in marshes), on 
sand bars and levees of the Rio Grande in Rio Grande Plains, w. to the Trans- 
Pecos and near rivers and lakes in s.e. and cen. Tex., summer-fall; widespread 
in warmer areas, nat. to Old World, adv. in Tex. 

Planted for erosion control along roads in dune areas. 

14. Phragmites Trin. 

A genus of 3 species, cosmopolitan; we have one. 
1. Phragmites communis Trin. Common reed. Figs. 93 and 94. 

Perennial reed with thick rhizomes; culms 1-3 m. tall, 5-15 mm. thick; ligule 
a short tough lacerate fringe; blades flat. 1-4 cm. broad; panicle a large terminal 
plume, many-branched and densely flowered; spikelets few-flowered, the lower 
flowers empty or merely staminate, the rest perfect; rachilla abscising at the 
upper part of each node, the fragments thus consisting of one floret with a 
portion of the densely long-silky-villous rachilla below (not above) the node; 
glumes lanceolate, shorter than the lowest lemma; lemmas lanceolate, glabrous, 
about 1 1 mm. long. 

Locally abundant in marshes, seeps, along rivers, at streamsides and canal 
banks, scattered throughout our region, fall; in most of the warmer parts of the 
world. 

15. Tridens R. & S. Trtoens 

Tufted or rarely shortly rhizomatous perennials; culms erect (or in one species 
scandent); ligule a white fringe or short fringed scale; blades mostly flat, elongate; 
panicles terminal, diffuse or spikelike; spikelets not much laterally compressed, 
several-flowered, all the florets perfect or the pistil of the uppermost usually abor- 
tive; rachilla abscising just below the lemma nodes; lemmas broad, mostly apically 
obtuse, emarginate and/or very shallowly cleft, 3-nerved (the midnerve and/or 
the laterals in some species minutely excurrent), usually pubescent on the lower 
half to two-thirds of the nerves (glabrous in T. albescens); paleas either glabrous 
or short silky-hairy on the nerves and dorsally. 

A North American genus of about a dozen species, in some works enlarged 
to include the related genus Erioneuron. 

1. Glumes as long as the spikelets or nearly so 1. T. strictus. 

1. Glumes about equaling the lowest lemma (2) 

2(1). Lemmas essentially glabrous (hair, if present, only at the basal callus of 
the lemma); panicles spikelike, 8-23 cm. long 2. T. albescens. 

2. Lemmas pubescent, at least at the base of the lateral nerves 

3. T. ambiguus. 

1. Tridens strictus (Nutt.) Nash. 

Culms 8-17 dm. long, erect; sheaths not keeled; blades 3-8 mm. broad; panicle 
spikelike, 1-3 dm. long, 9-15 mm. thick, with a few short appressed branches 
near the base; glumes as long as to longer than the rest of the spikelet, viscid, 
acuminate to a fine point, conspicuous in the panicle; lemmas about 3 mm. long, 
the lateral nerves reaching the distal margin and in some specimens excurrent, 
all 3 nerves hairy in the distal two-thirds the length. 

205 




Fig. 93: Phragmites communis: a, habit, lower part of culm and rhizome, X %; 
b, habit, culm and leaves, X %; c, leaf sheath, base of blade and ciliate ligule, X l^^. 
(From Mason, Fig. 80). 




Fig. 94: Phragmites communis: a, floret, showing the long-acuminate lemma, the 
short palea and the long silky hairs on rachilla joint, X 6; b, spikelet, showing the 
glumes and the florets successively smaller, X 4; c, habit, upper part of culm and 
panicle, X %; d, grain, X 16. (From Mason, Fig. 81). 



Infrequent in open forests on sandy soil, in mud at edge of ponds and lakes, 
along streams and low wet ground, in Okla. (Mayes Co.) and e., s.e. and n.-cen. 
Tex., summer-fall; s.e. U.S. n. to N.C., Tenn., 111. and Mo., w. to Kan., Okla. 
and Tex. 

2. Tridens albescens (Vasey) Woot. & Standi. White tridens. 

Tufts robust; culms 3-10 dm. long, erect; basal sheaths not or obscurely 
keeled; panicles spikelike, 8-25 cm. long, 5-13 mm. broad, very pale in color; 
lemmas about 3 mm. long, 3-nerved, the nerves ending well within the distal 
margin and glabrous (hair, if present, confined to the basal callus of the lemma. 

Abundant in roadside ditches, streamsides, overflows, in playa lakes, draws 
and low-lying prairies throughout Okla and Tex. to N.M. (Lea Co.), summer- 
fall; Okla. and Colo., s. to Tarn., N.L. and Coah. 

3. Tridens ambiguus (Ell.) Schult. 

Tufted; culms 6-10 dm. long, erect; basal sheaths keeled; panicle broadly to 
narrowly obovoid, 8-15 cm. long, the branches stifily ascending; most pedicels 
(of lateral spikelets) about 1 mm. long; spikelets erect, appressed to the branches; 
lemmas 3-4 mm. long, the 3 nerves usually minutely excurrent and pubescent in 
the lower two-thirds the length, or the lateral nerves scarcely excurrent in many 
specimens. 

Infrequent to rare, wet pinelands, boggy areas and wet savannahs, extreme 
e. Tex., late summer-fall; Coastal States, S.C. to Tex. 

16. Agropyron Gaertn. Wheatgrass 

Perennials; corners of base of blades discolored and minutely auriculate or 
pointed; inflorescences spikelike, the axis usually slightly zigzag, unbranched, re- 
maining intact; spikelets several-flowered, solitary (rarely in pairs) at each node, 
sessile, laterally compressed, turned with one side appressed to the rachis (or 
to the next spikelet above when crowded); all florets perfect or usually the 
terminal 1 or 2 reduced; rachilla abscising above the glume and at the lower 
part of each node; glumes lanceolate, acute, persistent, roundly keeled, equal, 
firm, several-nerved (the nerves obscure in some species); lemmas roundly keeled, 
5- to 7-nerved (nerves obscure in some species at some stages of maturity), firm 
to subindurate, lanceolae, acute or in some species awned, eventually the lateral 
margins revolute. 

A genus of about 100 or more species in temperate regions. 

1. Plants normally cespitose, non-rhizomatous 1. A. suhsecundum. 

1. Plants with creeping rhizomes; blades firm and strongly nerved (2) 

2(1). Glumes rigid, gradually tapering into a short awn, more or less asymme- 
tric, the lateral nerves usually obscure 2. A. Smithii. 

2. Glumes not rigid, acute or abruptly awn-pointed, symmetric, the lateral nerves 

evident 3. A. repens. 

1. Agropyron suhsecundum (Link) Hitchc. Bearded wheatgrass. 

Green or glaucous, without creeping rhizomes; culms erect, tufted, 5-10 dm. 
tall; sheaths glabrous or rarely pubescent; blades flat, 3-8 mm. wide; spike erect 
or slightly nodding, 6-15 cm. long, sometimes unilateral from twisting of the 
spikelets to one side, the rachis scabrous to scabrous-ciliate on the angles, 
sometimes disarticulating; spikelets rather closely imbricate, few-flowered, the 
rachilla villous, the callus of the florets short-pilose; glumes broad, rather 
prominently 4- to 7-nerved, nearly as long as the spikelet, tapering into an awn; 
lemmas obscurely 5-nerved, the nerves becoming prominent toward the tip, the 
awn straight or nearly so, usually 1-3 cm. long. 

208 




Fig. 95: Agropyron repens: plant, X %; spikelet and floret, X 3. (From Hitchcock 
& Chase). 



Moist or wet meadows, in water on edge of lakes and in open woods, in N. M. 
(Taos Co.) and Ariz. (Apache, Coconino and Gila cos.); Nfld. to Alas., s. to 
the mts. of Md., w. to Wash, and Calif., s. to N. M. and Ariz. 

2. Agropyron Smithii Rydb. Western wheatgrass. 

Forming large colonies by means of slender fragile easily detached rhizomes, 
the aerial culms erect even at the base; spikes strictly erect, rather dense, the 
spikelets overlapping usually more than their lengths. Elymus Smithii (Rydb.) 
Gould. 

In marshes and edge of water about lakes, along streams and ponds, oc- 
casionally in flowing water, in Okla. (Cimarron Co.), abundant (formerly) in 
the prairies of the higher parts of the Tex. Plains Country, infrequent e. to n.-cen. 
Tex. and w. to the Trans-Pecos, N. M. (Grant and Colfax cos.) and Ariz. 
(Apache, Navajo, Coconino, Yavapai and Pima cos.), late spring-summer; w. 
U.S. e. to O., Ky., Tenn., Ark. and Tex. 

This species apparently tends to disappear under grazing. 

Var. molle (Scribn. & Smith) M. E. Jones has pubescent lemmas. 

Var. Palmeri (Scribn. & Smith) Heller has densely pubescent sheaths. 

3. Agropyron repens (L.) Beauv. Quackgrass. Fig. 95. 

Greep or glaucous; culms erect or curved at base, 5-10 dm. tall, sometimes 
taller, with creeping yellowish rhizomes; sheaths of the innovations often pubes- 
cent; blades relatively thin, flat, usually sparsely pilose on the upper surface, 
mostly 6-10 mm. wide; spike 5-15 cm. long, the rachis scabrous on the angles; 
spikelets mostly 4- to 6-flowered, 1-1.5 cm. long, the rachilla glabrous or scaberu- 
lous; glumes 3- to 7-nerved, awn-pointed; lemmas mostly 8-10 mm. long, the 
awn from less than 1 mm. to as long as the lemma; palea obtuse, nearly as long 
as the lemma, scabrous on the keels. 

Waste places, meadows and pastures, also in seepage areas and wet meadows, 
in N. M. (Otero and Taos cos.) and Ariz. (Coconino Co.) Nfld. to Alas., s. 
to N.C., Ark., Ut. and Calif.; Mex.; introd. from Euras. 

A troublesome weed in cultivated ground. 

17. Elymus L. Wild-rye 

Perennials; culms slender; minute pointed auricles present at juncture of blade 
and sheath; inflorescence a terminal spike, the axis slender with short internodes, 
remaining intact; spikelets collaterally paired at each node, each basally only 
slightly laterally compressed and with one side toward the axis but each distally 
(due to contortion of rachilla) with 1 keel toward the axis; spikelets 2- to 6- 
flowered, all the flowers perfect except the terminal 1 or 2; glumes equal, firm 
to subindurate, lanceolate to subulate, 1- to several-nerved; lemmas lanceolate, 
cymbiform, not keeled, eventually subindurate, obscurely 5-nerved, awned from 
the tip in most species. 

A genus of about 70 species in temperate North America and South America. 

1. Rhizomes present; awns of lemmas 0-2 mm. long 1. E. triticoides. 

\. Rhizomes absent but base of culm usually decumbent; awns of lemmas 5-45 

mm. long (2) 

2(1). Glumes basally discolored, indurate, roundish in transection and diverging 
from the axis at a large angle, becoming broader and flatter toward 
the middle and then tapering to the awn 2. E. virginicus. 

2. Glumes basally flat, neither discolored, indurate nor rounded, diverging at 

a low angle, broadest near the base and tapering the full length to 
the awn 3. E. canadensis. 

210 




Fig. 96: Elymus triticoides: a, node, showing group of spikelets, X 4; b, floret, the 
lemma removed to show the lodicules, X 4; c, leaf sheath and ligule, X 4; d, floret, 
X 4; e, habit, X Vg; f, inflorescence, X %. (From Mason, Fig. 64). 



1. Elymus triticoides Buckl. Beardless wild-rye. Fig. 96. 

Perennial from creeping rhizomes; aerial culms erect, 6-12 dm. long; spikes 
erect, 7-20 cm. long, slender, the spikelets of successive nodes overlapping only 
a sixth to a half their lengths; spikelets paired; glumes subulate, much shorter 
than the body of the lemma; lemma tapering into a mucro or awn only 1-2 mm. 
long. 

On the dried or moist edges of meadows and flats, and in marshes about 
ponds, usually in heavy often alkaline soil, also flourishing as a weed in waste 
places, reported to occur in the Tex. Plains Country and Trans-Pecos; if present 
exceedingly rare and probably not nat., in N. M. (Dona Ana, Otero and Taos 
cos.) and Ariz. (Navajo, Coconino, Mohave, Yavapai, Greenlee and Pima cos.), 
spring; abundant in Pac. States, less frequent e. to the mts. of Mont., Wyo., 
Colo, and N. M. 

This species is apparently more closely related to species included in the genus 
Agropyron than it is to the other 2 species of Elymus below. 

2. Elymus virginicus L. 

Perennial; culms basally erect or very shortly decumbent, mostly erect, 
6-12 dm. long, peduncles (at maturity of the spike!) 7-30 cm. long; spikes 3-12 
cm. long, mostly erect or at least ascending; spikelets paired; glumes linear-elliptic, 
at the very base discolored, tending to be terete in transection, strongly indurate 
and diverging at a large angle from the axis but upward broader, flatter and less 
thoroughly indurate, 1.2-2.2 mm. broad near the middle and becoming more 
erect, tapered upward to a straightish ascending or slightly divergent awn 5-25 
mm. long. Incl. forms that have been called var. australis (Scribn. & Ball) 
Hitchc, var. glabrifiorus (Vasey) Bush and var. intermedius (Vasey) Bush. 

In mud and water of streams, ponds and marshy areas, in Okla. (Murray and 
Pittsburg COS.) and rather frequent in e., s.e., and n.-cen. Tex., less abundant 
in n. parts of Rio Grande Plains, Edwards Plateau and Plains Country, and Ariz. 
(Yavapai Co.), spring-summer; e. U.S. w. to Wash., Ida., Ut. and n. N. M., 
rare to n. Ariz. 

This species is highly variable. Many plants referred here show some characters 
of E. canadensis, with which this species undoubtedly intergrades. 

3. Elymus canadensis L. Canada wild-rye. Fig. 97. 

Perennial; culms basally decumbent, mostly ascending, 8-15 dm. long; 
peduncles (at maturity of the spike!) typically 25-45 cm. long, spikes 8-15 cm. 
long, nodding; spikelets usually paired or less commonly in threes at each node; 
glumes basally 0.7-1.2 (-1.4) mm. broad, ridge-keeled and fairly straight and 
diverging at a low angle, tapering into a slender scabrous outbowed awn, never 
becoming completely indurate but remaining flexible; lemmas glabrous to pubes- 
cent, with awns mostly 20-35 (-45) mm. long that diverge or curve away from 
the axis slightly or greatly. Incl. forms that have been called var. brachystachys 
(Scribn. & Ball) Farw., var. robustus (Scribn. & Sm.) Mack. & Bush and var. 
villosus (Muhl.) Shinners (£. villosus Muhl.). 

On wet mud along sluggish streams, in seepage areas, marshes and along 
streams, in Okla. (Haskell Co.), nearly throughout Tex. except s. part of Rio 
Grande Plains, N. M. (widespread) and Ariz. (Coconino, Apache, Navajo, s. to 
Cochise and Pima cos.); spring (less commonly summer), nearly throughout 
temp. N. A. (except Ala., Ga., Fla. and S. C). 

This species is somewhat variable and grades into E. virginicus. 

212 




Fig. 97: Elymus canadensis: plant, X i/^; spikelet and floret, X 5. (From Hitchcock 
& Chase). 




Fig. 98: Hordeum brachyantherum: plant, X V-z; group of spikelets and floret, X 3. 
(From Hitchcock & Chase). 



18. Hordeum L. Barley 

Tufted annuals (frequently some perennial); inflorescences dense terminal 
spikes; rachis abscising at the lower part of each node; spikelets in threes at each 
node, the central one largest, the lateral ones reduced and pedicellate, 1 -flowered; 
lemma contorted so that its back is abaxial; rachilla produced beyond the lemma 
node as a point; glumes setaceous, produced into awns; lemmas cymbiform or 
flatter, not keeled, obscurely 5-nerved, tapering into an awn. 

A genus of about 20 species of temperate regions. 

1. Awns 2-5 cm. long; spike nodding 1. H. jubatum. 

1. Awns mostly less than 1 cm. long; spike erect 2. H. brachyantherum. 

1. Hordeum jubatum L. Foxtail barley. 

Short-lived perennial or often behaving as a spring annual; culms basally de- 
cumbent, mostly ascending, 30-65 cm. long; spikes 2-1 1 cm. long (not including 
awns) and about 1 cm. thick (not including awns), nodding, dense, the rachis 
abscising at the lower part of each node; spikelets in threes at each node, the 
lateral ones pedicelled and with slightly smaller lemmas than the central one and 
merely staminate; awns of the various glumes and lemmas not curved at maturity, 
25-60 mm. long. 

Moist open ground, along ditches, in marshes and seepage areas, in shallow 
water streams, and in waste places, often on alkaline or saline soils; a trouble- 
some weed, especially in irrigated lands, in Okla. {Waterfall) and in Tex. Plains 
Country and Trans-Pecos, in N. M. (Colfax, Taos, DeBaca, San Juan, Valencia 
and McKinley cos.) and Ariz. (Coconino, Navajo, Apache and Maricopa cos.), 
spring; w. U. S. e. to Plains States and as a weed e. to N. E. 

Var. caespitosum (Scribn.) Hitchc. has awns 1.5-3 cm. long. 

2. Hordeum brachyantherum Nevski. Meadow barley. Fig. 98. 

Perennial; culms tufted, erect or sometimes spreading, 1-5 dm. tall; blades 
soft, usually glabrous, sometimes scabrous or shortly pubescent, 3-9 mm. wide; 
spike slender, 2-8 cm. long; glumes all setaceous, 8-15 mm. long, those of the 
central spikelet often scarcely longer than the palea; the rachilla prolonged, 
usually extending beyond the middle of the palea; lateral spikelets pediceled, 
the pedicels usually curved, the florets much-reduced. 

Wet meadows, flats, marshes, lakes or ponds and their borders, often in sub- 
alkaline or saline soils, in N. M. (San Juan, Rio Arriba, Taos, McKinley and 
Valencia cos.) and Ariz. (Coconino, Apache, Greenlee, Maricopa, Cochise and 
Pima COS.); Nfld. to Alas., s. to N. M., Ariz, and Calif. 

19. Lolium L. 

Inflorescences elongate, terminal, lax spikes; axis sculptured with a niche for a 
spikelet on one side of each internode, the axis remaining intact; spikelets 2-ranked, 
solitary, each fitting within the niche of the internode, slightly if at all laterally 
compressed, 5- to 20-flowered, all the florets perfect except the terminal one; 
rachilla eventually abscising above the glume (s) and at the lower part of each 
node; first glume obsolete or much reduced, adaxial when present (thus hidden 
except on terminal spikelet), 3- to 5-nerved; second glume abaxial, strongly 5- to 
7-nerved, membranous, obtuse; lemmas broadly ovate, 5- to 7-nerved, eventually 
marginally revolute. 

A genus of perhaps 12 species in temperate Eurasia. 

1. Lolium perenne L. Ryegrass. Fig. 99. 
Tufted perennial; culms 3-10 dm. long, mostly erect; spikes 7-25 cm. long, 

215 




Fig. 99: Lolium perenne: plant, X V2', spikelet, X 3; floret, X 5. (From Hitchcock 
& Chase). 




Fig. 100: Parapholis incurva: a, habit variation, culm erect, X %; b, leaf sheath, 
ligule and blade, X 8; c, part of spike, showing spikelets embedded in the cylindric 
articulate rachis, X 6; d, habit, the culms decumbent and the spikes strongly curved, 
X %. (From Mason, Fig. 76). 



compressed; spikelets 4- to 20-flowered; second (only) glume 6-10 (-14) mm. 
long, from less than a third to nearly as long as the rest of the spikelet; lemmas 
awnless or short-awned. L. multiflonim Lam. 

Scattered in lawns and other disturbed areas, in mud and shallow water of 
ponds and lakes, in Okla. (McCurtain Co.), over most of Tex. except the Rio 
Grande Plains, N. M. (San Juan Co.) and Ariz. (Coconino, Pinal, Cochise, Santa 
Cruz and Pima cos.), spring; nat. of Eur., now widely introd. in temp, parts of 
N. A. and S. A. 

20. Parapholis C. E. Hubb. 

A genus of 4 species in the Old World. 

1. Parapholis incurva (L.) C. E. Hubb. Sicklegrass. Fig. 100. 

Tufted annual; culms 1-3 dm. long, decumbent most of their length, terminally 
arcuate upward; internodes short; sheaths loose, departing from and revealing 
the internodes which they only slightly exceed in length; blades of upper leaves 
shorter than their sheaths; inflorescences not fully exserted, arcuate, terminal, 
lax, nearly terete or somewhat compressed-cylindrical; spikes 3-10 cm. long and 
only about 3 mm. thick; rachis of spikes eventually abscising at the lower part 
of each node, the internodes sculptured, each with a niche for a spikelet; spikelets 
2-ranked, solitary at each node, 1 -flowered, the only parts visible being the halves 
of the 2 strongly nerved lanceolate-acute glumes; lemma adaxial, flattened, fitting 
into the niche of the internode, 4-7 mm. long. Pholiurus incurvus (L.) Schinz & 
Thell. 

Brackish shores and ditches, salt marshes and tidal mud flats along the coast 
of s.e. Tex., s.w. to San Patricio Co., spring; nat. of Eur., now established in 
many coastal areas of N. A. 

21. Sphenopholis Scribn. Wedgegrass 

Soft tufted perennials; culms ascending, inflorescence a terminal panicle with 
much-branched main branches, these usually appressed or at least ascending; 
pedicels abscising just below the spikelets; spikelets slightly laterally compressed, 
2- or 3-flowered, all flowers perfect (?); rachilla extended beyond the last lemmas 
as a bristle; first glume linear-filiform, green; second glume usually slightly exceed- 
ing the first in length, broadly obovate, truncate to slightly acute apically, mar- 
ginally broadly hyaline or at least thin, medially green and obscurely 3- to 5-nerved, 
the median nervate portion in some species coriaceous or even thickly verrucose 
and scabrous along the veins, clasping the second lemma; first lemma lanceolate, 
thin-chartaceous or marginally hyaline, shiny, in almost all species perfectly 
glabrous; second lemma shorter than the first, similar in texture but in several 
species scabrous (at least toward the tip), often cellulose under high magnification; 
paleae hyaline, as long as the lemmas, shiny. 

A North American genus of about a dozen species. 

1. Panicle dense, often spikelike, erect; second glume very broad, obtuse 

1.5. obtiisata. 

1. Panicle rather loose, nodding, never spikelike; second glume subacute 

2. S. intermedia. 

1. Sphenopholis obtusata (Michx.) Scribn. Prairie wedgescale. Fig. 101. 

Perennial; culms leafy, 1-10 dm. long, basally 1-2.5 mm. thick, shortly de- 
cumbent, geniculate at the lower nodes, mostly ascending or erect; blades 3-12 mm. 
broad, flat; panicle dense, usually interrupted-spiciform or slightly more open, 
3-18 cm. long, 5-20 mm. broad, with pedicels about 0.5 mm. long, a 1-cm. 
transection through the middle enclosing about (20) 30 to 75 spikelets; spikelets 
rarely gaping, usually yellowish; first glume 1.3-2.3 mm. long; second glume very 

218 




Fig. 101: 1, SphenophoUs obtusata: plant, X V-y, glumes and floret, X 10. 2, Sphe- 
nopholis intermedia: panicle, X 1; glumes and floret, X 10. (From Hitchcock & Chase), 



blunt, almost cucullate, with a distinct line separating the chartaceous to sub- 
coriaceous convex median portion from the flat thin margins, 1.7-2.4 mm. long; 
lowest lemma usually microscopically cellulose-pustulate or scaberulous toward the 
apex, 1.9-2.7 mm. long; second lemma often more scabrous than the first. 

In moist swales, in water of creeks, in seepage areas and wet soils, Okla. 
(Waterfall), essentially throughout Tex., N.M. (Colfax, DeBaca, Eddy and 
Guadalupe cos.) and Ariz. (Apache, Navajo, Coconino, Yavapai, Pinal, Cochise 
and Pima cos.), spring; s. Can. and nearly all of U. S. and higher parts of Mex. 

2. Sphenopholis intermedia (Rydb.) Rydb. Fig. 101. 

Cespitose short-lived perennial, sometimes flowering as a winter annual, usually 
3-10 dm. tall, glabrous or scabrous to pubescent; ligules 1.5-2.5 mm. long, finely 
erose-ciliate and irregularly toothed, glabrous or sometimes scabridulous externally; 
blades flat, 2-5 mm. wide, scabridulous; panicle 7-20 cm. long, narrow but the 
individual crowded erect branches usually plainly distinguishable; first glume nar- 
rowly linear, 1.6-2.5 mm. long; second glume oblanceolate, obtuse to subacute, 
2.2-2.5 mm. long, about one fourth as wide as the first; lemmas 2.5-3 mm. long; 
anthers about 0.6 mm. long. 

On the edge of water of lakes, ponds and along streams, in Ariz. (Navajo and 
Cochise cos.); Nfld. to B. C, s. to Fla. and Ariz. 

22. Trisetum Pers. 

Tufted perennials with flat blades and open or usually contracted or spikelike 
shining panicles; spikelets usually 2-flowered, sometimes 3- to 5-flowered, the 
rachilla prolonged behind the upper floret, usually villous; glumes somewhat un- 
equal, acute, the second usually longer than the first floret; lemmas usually short- 
bearded at base, 2-toothed at apex with the teeth awned, bearing from the back 
below the cleft apex a straight and included or usually bent and exserted awn 
(rarely essentially awnless in T. IVolfii). 

A genus of 75 species in temperate regions. 

1. Awn essentially wanting, included within the glumes 1. T. Wolfii. 

1. Awn exserted (2) 

2(1). Panicle open, rather densely flowered but not spikelike 2. T. montanum. 

2. Panicle dense, spikelike, i.iore or less interrupted below 3. T. spicatum. 

1. Trisetum Wolfii Vasey. Wolf's trisetum. 

Perennial; culms erect, 5-10 dm. tall, loosely tufted, sometimes with short 
rhizomes; sheaths scabrous, rarely with the lower pilose; blades flat, scabrous, 
rarely pilose on the upper surface, 2-4 mm. wide; panicle erect, rather dense 
but scarcely spikelike, green or pale, sometimes a little purplish, 8-15 cm. long; 
spikelets 5-7 mm. long, 2-flowered or sometimes 3-flowered; glumes nearly equal, 
acuminate, about 5 mm. long; lemmas obtusish, scaberulous, 4-5 mm. long, 
awnless or with a minute awn below the tip, the callus hairs scant, about 0.5 mm. 
long, the rachilla internode about 2 mm. long, rather sparingly long-villous. 

In wet meadows and wet soil along mt. streams, in N. M. {Hitchcock); Mont. 
to Wash., s. to N. M. and Calif. 

2. Trisetum montanum Vasey. 

Perennial about 5 dm. tall, with narrow blades; sheaths from nearly glabrous to 
softly retrorsely pubescent; panicle open, rather densely flowered but not spikelike, 
often purple-tinged; spikelets 5-6 mm. long, disarticulating above the thinnish 
glumes; awns delicate, 5-8 mm. long; rachilla villous. 

220 




Fig. 102: Trisetum spicatum: plant, X y^', spikelet and floret, X 5. (From Hitchcock 
& Chase). 



Wet mt. meadows, gulches and moist places on mt. slopes, in N. M. (San 
Miguel, Taos, and Lincoln cos.) and Ariz. (Graham Co.); Colo., Ut., N. M. 
and Ariz. 

3. Trisetum spicatum (L.) Richt. Spike trisetum. Fig. 102. 

Culms densely tufted, erect, 15-50 cm. tall, glabrous to puberulent; sheaths 
and usually the blades puberulent; panicle dense, usually spikelike, often inter- 
rupted at base, pale or often dark purple, 5-15 cm. long; spikelets 4-6 mm. long; 
glumes somewhat unequal in length, glabrous or scabrous except the keels, or 
sometimes pilose, the first narrow, acuminate and 1-nerved, the second broader, 
acute and 3-nerved; lemmas scaberulous, 5 mm. long, the first longer than the 
glumes, the teeth setaceous; awn attached about one third below the tip, 5-6 mm. 
long, geniculate, exserted. 

Wet alpine meadows and slopes, in N. M. (Mora, Rio Arriba and Sandoval 
COS.) and Ariz. (Apache and Coconino cos.); Arctic America, southw. to Conn., 
Pa., Mich, and Minn., in the mts. to N. M., Ariz, and Calif.; also w. N. C; 
through Mex. to the Antarctic regions of S. A.; arctic and alpine regions of the 
Old World. 

23. Deschampsia Beauv. Hair-grass 

Low or moderately tall annuals or usually perennials with shining pale or 
purplish spikelets in narrow or open panicles; spikelets 2-flowered, disarticulating 
above the glumes and between the florets, the hairy rachilla prolonged beyond 
the upper floret and sometimes bearing a reduced floret; glumes about equal, 
acute or acutish, membranaceous; lemmas thin, truncate and 2- to 4-toothed at 
summit, bearded at base, bearing a slender awn from or below the middle, the 
awn straight, bent or twisted. 

About 60 species in temperate and cold regions, and in tropical mountains, in 
both hemispheres. 

1. Annual; panicle open, the stiffly ascending capillary branches usually in 
twos 1. D. danthonioides. 

1. Perennials; panicle narrow or open, the slender branches appressed or droop- 

ing (2) 

2(1). Glumes usually longer than the florets; panicle usually narrow, as much as 

3 dm. long, the branches appressed; blades filiform, lax 

2. D. elongata. 

2. Glumes shorter than the florets; panicle open, nodding, 1-2.5 dm. long, the 

branches drooping; blades firm, flat or folded 3. D. caespitosa. 

1. Deschampsia danthonioides (Trin.) Munro ex Benth. Annual hairgrass. 

Annual; culms slender, erect. 15-60 cm. tall; blades few, short, narrow; panicle 
open, 7-25 cm. long, the capillary branches commonly in twos, stiflly ascending, 
naked below, bearing a few short-pediceled spikelets toward the ends; glumes 4-8 
mm. long, 3-nerved, acuminate, smooth except the keel, exceeding the florets; 
lemmas smooth and shining, somewhat indurate, 2-3 mm. long, the base of the 
florets and the rachilla pilose, the geniculate awns 4-6 mm. long. 

In mud about lakes and ponds, along streams and wet meadows, in Ariz. 
(Coconino and Cochise cos.); Mont, to Alas., s. to Ariz, and Baja Calif.; Arg. 
and Chile. 

2. Deschampsia elongata (Hook.) Munro ex Benth. Slender hair grass. 

Perennial; culms densely tufted, slender, erect, 3-12 dm. tall; blades soft, 
1-1.5 mm. wide, flat or folded, those of the basal tuft filiform-involute; panicle 
very narrow, 15-30 cm. long, the capillary branches strictly appressed; spikelets 
on short appressed pedicels; glumes 4-6 mm. long, 3-nerved, as long as or 

222 




Fig. 103: Deschampsia caespitosa: a, habit, X %; b, rachis section, X 5; c, node 
section, X 5. d-f, branchlets and spikelets with florets in progressive stages of develop- 
ment, X 5. (V. F.). 



slightly longer than the florets, more or less purplish-tinged; lemmas 2-3 mm. 
long, smooth and shining, somewhat indurate, the awns straight, to twice as long 
as the glumes. 

Moist or wet soil in meadows, along streams, on open or wooded slopes, in 
Ariz. (Mohave, Graham and Pima cos.); Alas, to Wyo., s. to Ariz., Calif, and 
Mex.; Chile. 

3. Deschampsia caespitosa (L.) Beauv. Tufted hair grass. Fig. 103. 

Perennial; culms densely tufted, erect, 5-15 dm. tall (alpine forms reduced); 
leaves mostly basal, flat or folded, 1.5-4 mm. wide, short or often elongate; 
panicle open, nodding (condensed, with short, usually appressed branches in 
Deschampsia caespitosa subsp. holciformis) , 10-25 cm. long, capillary, the 
scabrous branches spikelet-bearing toward the ends; spikelets 3.5-7 mm. long, 
green or purple-tinged, the florets distant, the rachilla joint one half as long as the 
lower floret; glumes acute, glabrous or minutely scabrous; lemmas smooth, the 
awns from near the base, from straight and included to slightly bent and twice 
as long as the spikelet. 

Bogs, wet mt. meadows, edges of marshes and in shallow water, in N. M. 
(Otero and Taos cos.) and Ariz. (Apache, Coconino and Cochise cos.); Greenl. 
to Alas., s. to N. C, 111., N. D., N. M., Ariz, and Calif.; s. Arg. and Chile; also 
the Old World. 

24. Holcus L. 

About 8 species in the Canaries, Eurasia and North Africa and South Africa. 

1. Holcus lanatus L. Velvet grass. Fig. 104. 

Plant grayish, velvety-pubescent; culms erect, 3-10 dm. tall, rarely taller; 
blades 4-8 mm. wide; panicles 8-15 cm. long, contracted, pale, purplish-tinged; 
spikelets 4 mm. long; glumes villous, hirsute on the nerves, the second broader 
than the first, 3-nerved; lemmas smooth and shining, the awn of the second hook- 
like. 

Open ground, wet meadows and wet or moist places, in Okla. (Delaware Co.) 
and Ariz. (Coconino Co.); Me. to Okla. and Colo. s. to Ga. and La.: common 
on the Pac. coast, B.C. and Mont, to Ariz, and Calif.; introd. from Eur., wide- 
spread in Can. and U.S. 

25. Danthonia Lam. & DC. Oatgrass 
About 10 species in warm regions. 
1. Danthonia intermedia Vasey. Timber oatgrass. 

Culms 1-5 dm. tall; sheaths glabrous (the lower rather pilose) with long hairs 
in the throat; blades subinvolute or those of the culm flat, glabrous or sparsely 
pilose; panicle purplish, narrow, few-flowered, 2-5 cm. long, the branches 
appressed, bearing a single spikelet; glumes about 15 mm. long; lemmas 7-8 mm. 
long, appressed-pilose along the margin below and on the callus, the summit 
scaberulous, the acuminate teeth aristate-tipped; terminal segment of awn 5-8 mm. 
long; palea narrowed above, notched at the apex. 

Wet meadows and bogs in N. M. (Pecos National Forest) and Ariz. (Apache, 
Coconino and Graham cos.); Nfld. and Que. to Alas., s. to n. Mich., N. M., Ariz, 
and Calif. 

26. Calamagrostis Adans. Reed-grass 

Perennial usually moderately tall grasses, mostly with creeping rhizomes, with 
small spikelets in open or usually narrow sometimes spikelike panicles; spikelets 
1 -flowered, the rachilla disarticulating above the glumes, prolonged behind the 

224 




Fig. 104: Holcus lanatus: plant, X %; spikelet, florets and mature fertile floret, X 5. 
(From Hitchcock & Chase). 



palea as a short commonly hairy bristle; glumes about equal, acute to acuminate; 
lemmas shorter and usually more delicate than the glumes, usually 5-nerved with 
the midnerve exserted as an awn, the callus bearing a tuft of hairs that are often 
copious and as long as the lemma. 

About 80 species in temperate and cold regions of the world; especially 
abundant in the South American Andes. 

1. Panicle nodding, rather loose and open; callus hairs copious, about as long as 
the lemma 1. C canadensis. 

1. Panicle erect, dense or spikelike, more or less interrupted below; callus hairs 
shorter than the lemma 2. C inexpansa. 

1. Calamagrostis canadensis (Michx.) Beauv. Blue-joint. Fig. 105. 

In small or large tussocks; culms suberect, 6-15 dm. tall, with numerous 
creeping rhizomes; sheaths glabrous or rarely obscurely pubescent; blades numer- 
ous, elongate, flat, rather lax, scabrous, 4-8 mm. wide; panicle nodding, from 
narrow and rather dense to loose and relatively open (especially at base), 10-25 
cm. long; glumes usually 3-4 mm. long, smooth or more commonly scabrous, 
acute to acuminate; lemma nearly as long as the glumes, smooth, thin in texture, 
the awn delicate, straight, attached, near or just below the middle and extending 
to or slightly beyond its tip, the callus hairs abundant, about as long as the lemma; 
rachilla delicate, sparsely long-pilose. 

Marshes, wet places, open woods and wet meadows, in N.M. (Taos Co.) and 
Ariz. (Apache, Coconino, Graham and Pima cos.), spring-fall; Greenl. to Alas., 
s. to W.Va., N.C., Mo., Kan., N.M. and Calif. 

A variable species that comprises several varieties. We have two segregated by 
Fernald as follows: 

1. Spikelets 2-3.8 mm. long; glumes rounded on the back, weakly keeled, acute 
or acuminate; lemma 1.7-3 mm. long; awn inserted near middle of 
lemma var. canadensis. 

1. Spikelets 3.8-6 mm. long; glumes narrow, strongly keeled, distinctly acumi- 

nate; lemma 3-4.2 mm. long; awn inserted on lower third of lemma 
var. robusta Vasey. 

2. Calamagrostis inexpansa Gray. Northern reedgrass. Fig. 105. 

Culms tufted, 4-12 dm. tall, with rather slender rhizomes, often scabrous 
below the panicle; sheaths smooth or somewhat scabrous, the basal ones numerous, 
withering but persistent; ligule 4-6 mm. long; blades firm, rather rigid, flat or 
loosely involute, very scabrous, 2-4 mm. wide; panicle narrow, dense, the 
branches mostly erect and spikelet-bearing from the base, 5-15 cm. long; glumes 
3—4 mm. long, abruptly acuminate, scaberulous; lemma as long as glumes, 
scabrous, the awn attached about the middle, straight or nearly so, about as long 
as glumes, the callus hairs Vi to % as long; rachilla 0.5 mm. long, some of the 
hairs reaching to tip of lemma. 

Meadows, marshes and wet places, in N. M. (San Juan and San Miguel cos.) 
and Ariz. (Coconino and Apache cos.), spring-fall; Greenl. to Alas., s. to Me., 
Va., Wash., N. M. and Calif. 

Our plant has been designated as var. brevior (Vasey) Stebbins with smaller 
parts than in var. inexpansa; these being spikelets 3-4.5 mm. long; lemma 2.5-3.5 
mm. long; palea 1.7-2.6 mm. long. 

27. Agrostis L. Bentgrass 
Annual or usually perennial herbs; culms glabrous; blades flat; inflorescences 
paniculate; spikelets one-flowered, very slightly laterally compressed; zone of 
abscission between the glumes and the lemma (in ^. semiverticillata a zone of 
abscission also in the pedicel below the glumes); lemma shorter than the glumes, 
awned or awnless. 

226 




fi^^^^^ 



Fig. 105: A, Calamagrostis canadensis: plant, X %; glumes and floret, X 10. B, 
Calamagrosds inexpansa: panicle, X 1; glumes and floret, X 10. (From Hitchcock & 
Chase). 



A genus of 150 to 200 species, chiefly in the North Temperate Zone. 

1. Longest glume shorter than 2 mm. (2) 

1. Longest glume longer than 2 mm. (3) 

2(1). Panicle very dense with short scabrous branchlets that are many-flowered 
nearly to the base; stolons present 1. A. semiverticillata. 

2. Panicle very diffuse; branchlets long and naked most of their length, the spike- 

lets crowded toward the tips; stolons absent 2. A. hyemalis. 

3(1). Tufted perennials without rhizomes or stolons; panicles open and/or 
diffuse, the branches mostly naked (4) 

3. Perennials with stolons or rhizomes or the lower intemodes reclining and sub- 

rhizomatous; panicles sometimes open but not diffuse, the branches 
bearing flowers for at least half their length (6) 

4(3). Panicle very diffuse, irregularly rounded, the main branches forking toward 
the end or above the middle, the pedicels short, the spikelets 
crowded near the end of the branches 3. A. scabra. 

4. Panicle open but not diffuse, subpyramidal, the main branches forking at or 

below the middle; pedicels and spikelets not as above (5) 

5(4). Spikelets about 2 mm. long; plants of high altitudes, delicate, mostly 1-3 
dm. tall 4. A. idahoensis. 

5. Spikelets 2-3 mm. long; plants somewhat robust, of lower elevations 

5. A. perennans. 

6(3). Panicles more than 25 mm. broad, the branches spreading; rhizomes pre- 
sent, 2-3 mm. thick 6. A. stolonifera. 

6. Panicles less than 25 mm. broad, the branches ascending or appressed; 

rhizomes absent but stolons often present (7) 

7(6). Palea present 7. A. palustris. 

7. Palea absent 8. A. exarata. 

1. Agrostis semiverticillata (Forsk.) Christ. Water bentgrass. Fig. 106. 

Stoloniferous perennial freely rooting at the nodes; aerial culms 2-5 dm. long, 
1-2 mm. thick, leafy; ligule a thin scale 2-7 mm. long; blades 4-14 cm. long, 2-7 
mm. broad, flat; panicle 3-10 cm. long, 1-3 cm. thick, ellipsoidal, very dense; 
swollen zone of abscission present on the scabrous pedicellary branchlets below 
the spikelets; glumes 1.3-2 mm. long, scabrous; lemma about 1 mm. long or 
shorter, truncate; palea narrow, as long as lemma. Polypogon semiverticillatiis 
(Forsk.) Hylander. 

At the edges of streams in calcareous mud, along irrigation ditches, seepage 
and in shallow water, in Okla. (Cimarron Co.), n.-cen. Tex., Edwards Plateau, 
Plains Country and Trans-Pecos, locally abundant, N.M. (Guadalupe. De Baca 
and Eddy cos.) and Ariz. (Apache to Mohave, s. to Cochise, Santa Cruz and 
Pima COS.), Apr. -June and continuing now and then into Nov.; warmer parts of 
the world, in N. A. n. to Wash., Nev., Ut., Colo., and Tex., introd. from the Old 
World. 

2. Agrostis hyemalis (Walt.) B.S.P. Spring bentgrass. Fig. 107. 

Tufted perennial; culms 1-6 dm. long, 0.5-1 mm. thick, leafy, erect or the 
lowermost internodes reclining; ligule a thin scale 1-4 mm. long; blades 3-9 cm. 
long, 1-2 mm. broad, flat; panicle 5-30 cm. long, at least half as broad at 
maturity, open and very diffuse, the long branches capillary and mostly naked, 
branched in the outer third; spikelets crowded at the ends of the branchlets, 
appressed; glumes 1.5-2.1 mm. long, subequal; lemma 1-1.3 (-1.5) mm. long, 
awnless; palea absent. 

228 




Fig. 106: Agrostis semiverticillata: a, habit, showing culms with decumbent base, 
short horizontal leaf blades and panicles, X %; b, young floret, showing the truncate 
lemma toothed at apex, X 12; c, branchlets of panicle, showing inflated base, X 4; d, 
flowering spikelet, the glumes scabrous, X 20; e and f, leaf sheath, dentate ligule and 
scabrous blade, X 4. (From Mason, Fig. 56). 




Fig. 107: Agrostis hyemalis: plant, X V2; glumes and floret, X 5. (From Hitchcock 
& Chase). 



Usually moist sandy soil, in water of ponds and lakes, and seepage along 
streams, roadsides and other open places in Okla. {Waterfall) and in most of Tex. 
except w. Plains Country, scattered, Mar-May, rarely to June; e. U.S. w. to Kan., 
Okla. and Tex. 

3. AgTOStis scabra Willd. 

Similar to A. hyemalis but the glumes 2-2.6 mm. long, some of them on any 
plant at least 2.2 mm. long; lemma 1.3-1.6 mm. long, rarely as short as 1.2 mm.; 
palea absent. A. hyemalis var. tenuis (Tuckerm.) GI. 

Moist soil, in flowing water of streams, wet meadows and in mud on edge of 
ponds and lakes, and openings in forests, at elev. of 6,000-8,300 ft. in the Tex. 
Trans-Pecos mts. where probably nat., also scattered in other parts of the state 
(Dallas, Hardin and Harris cos., etc.) where introd., N.M. (Taos and Colfax cos.) 
and Ariz. (Pima, Coconino, Apache, Navajo, Yavapai, Graham, Santa Cruz and 
Cochise cos.), July-Sept, in the mts., Apr.-May elsewhere; most of cool temp. N.A. 

4. Agrostis idahoensis Nash. 

Tufted delicate perennial 1-4 dm. tall; ligules 1-2 (-3) mm. long, acute to 
obtuse, erose-ciliolate and often lacerate; blades mostly lax and flat but some- 
times folded, 0.5-1.5 mm. wide; panicle narrow but not compressed, usually 
5-10 cm. long, the capillary branches ascending and forking below the middle and 
bearing few spikelets; glumes green or purplish, acute, scabridulous on the keel 
but not on back, usually 1.6-2.4 or sometimes 2.6 mm. long, the first somewhat 
the longest; lemma about three fourths as long as the glumes, unawned, only 
slightly bearded (at most) on the callus; palea lacking or not over 0.2 mm. long; 
anthers about 0.3 mm. long; lodicules 0.2-0.3 mm. long. 

In wet mt. meadows, swamps, shallow water of ponds, lakes, along streams 
and on sand-gravel bars in river beds, in N. M. (Rio Arriba and Taos cos.) and 
Ariz. (Apache and Coconino cos.); Mont, to Wash., s. to N.M., Ariz, and Calif.; 
Alas. 

5. Agrostis perennans (Walt.) Tuckerm. Autumn bentgrass. 

Tufted perennial; culms 25-100 cm. long, 0.5-2.5 mm. thick, leafy, erect or 
the lowest internodes reclining; ligule a scale 1-3 mm. long; blades 5-22 cm. 
long, 1-6 mm. broad, flat; panicle 1-3 dm. long, about half as broad, often sub- 
pyramidal, very diffuse, open, some of the main branches branched near the middle 
or slightly above, the pedicellary branchlets appressed or often more divaricate; 
glumes 2-3.2 mm. long; lemma shorter, awnless (in ours, elsewhere rarely awned); 
palea absent. 

Moist sandy soils along streams and about ponds, in marshes and wet meadows, 
in Okla. {Waterfall), e. Tex. and N. M. (Otero and Sandoval cos.), infrequent, 
Oct.; Que. and e. U.S. w. to Neb., Kan., Okla., Tex. and N. M.; also Mex. 

6. Agrostis stolonifera L. Redtop bentgrass. Fig. 108. 

Perennial from rhizomes 2-3 mm. thick; aerial culms 35-100 cm. long, 1.5-2.5 
mm. thick, the lower internodes usually decumbent, leafy; ligule a thin scale 4-8 
mm. long; blades 6-20 cm. long, 3-8 mm. broad, flat; panicle 12-25 cm. long, less 
than half as broad, the branches spreading; glumes equal, 2-3 mm. long, gaping; 
lemma nearly as long as the glumes, not awned; palea about two thirds as long 
as the lemma. Often called A . alba L. but that name pertains to a species of Poa. 
A. gigantea Roth. 

Wet meadows and stream banks, swampy prairies, Typha marshes and ditches, 
in Okla. (Alfalfa Co.) and e. and n.-cen. Tex., the Plains Country and Trans-Pecos 
mts., scattered, mostly in tame pastures, in N. M. (Sandoval and Colfax cos.) and 

231 




Fig. 108: Agrostis stolonifera: a, scabrous branchlets of panicle, X 6; b, leaf sheath, 
ligule and blade, X 6; c, habit, showing the decumbent culms and flat leaf blades, X %; 
d, floret, showing lemma, X 20; e, floret, showing the short, emarginate palea, X 20; 
f and g, grains (caryopses), X 20; h, habit, upper part of culm showing panicle, X V^; 
i, spikelet, showing the glumes, each with scabrous keel, X 16. (From Mason, Fig. 55). 




Fig. 109: Agrostis exarata: a, leaf sheath, ligule and blade, X 5; b, spikelet in lower 
part of panicle, X 3; c, habit, showing the leafy culms and young close panicle, X %; 
d, upper part of culm, showing panicle, X %; e, floret, X 14; f, spikelet, the glumes 
each with a scabrous keel, X 14. (From Mason, Fig. 54). 



Ariz. (Apache, Navajo, Coconino, Yavapai, Greenlee and Cochise cos.), summer; 
widespread in temp. N. A., introd. from Euras. 

7. Agrostis palustris Huds. Creeping bentgrass. 

Perennial; culms decumbent, often long-stoloniferous, the aerial ones erect, 
3-5 dm. long, 1-2 mm. thick, leafy; ligule a thin scale 2-4 mm. long; blades 4-10 
cm. long, 1-3.5 mm. broad, flat; panicles 5-15 cm. long, 1-2 cm. thick, the short 
branches ascending; glumes 2-3 mm. long; lemma about two thirds as long as the 
glumes, not awned; palea about two thirds as long as the lemma. 

Fresh-water shores of lakes and ponds, along streams and ditches, in wet 
meadows and marshes in s.e. Tex., N.M. (Taos Co.) and Ariz. (Coconino, 
Yavapai, Gila and Pinal cos.), scattered or rare, summer; widely introd. in temp. 
N. A. from Euras. 

8. Agrostis exarata Trin. Spike bentgrass. Fig. 109. 

Tufted perennial; culms 3-9 dm. long, 1-2 mm. thick (in ours; more robust else- 
where), leafy, mostly erect or the lower internodes reclining and substoloniferous; 
ligule a scale 3-5 mm. long; blades 4-20 cm. long. 2-8 mm. broad, flat; 
panicle 1-3 dm. long, 10-25 mm. thick, rather lax and often somewhat interrupted 
toward the base, the branches many-flowered, appressed; glumes 2.5-3 mm. long, 
narrowly acuminate; lemma 1.7-2.3 mm. long, not awned (in ours; elsewhere 
apically awned); palea absent. 

Wet places such as marshes, wet meadows, flowing water and along streams, at 
high elev. in Tex. Trans-Pecos mts., rare, in N. M. (Union, Guadalupe and 
Otero cos.) and Ariz. (Apache to Coconino, s. to Cochise and Pima cos.), late 
summer; w. Can. and w. U. S. (including Alas.), e. to S. D., Neb. and in the mts. 
to w. Max. 

28. Cinna L. Woodreed 

Tall perennials with flat blades and close or open panicles; spikelets 1 -flowered, 
disarticulating below the glumes, the rachilla forming a stipe below the floret 
and produced behind the galea as a minute bristle; glumes equal or subequal, 
1- to 3-nerved; lemma similar to the glumes, nearly as long, 3-nerved, bearing a 
minute short straight awn just below the apex or rarely awnless; palea 1 -keeled. 

A genus of 4 species in Eurasia, North America and South America. 

1. Spikelets 5 mm. long; panicle rather dense, the branches ascending 

1. C. arundinacea. 

1. Spikelets 3.5-4 mm. long; panicle loose, the branches spreading or drooping 
2. C. latifoUa. 

1. Cinna arundinacea L. Stout woodreed. Fig. 110. 

Clumped perennial with short thick rhizomes; aerial culms erect, 7-15 dm. tall, 
2-5 mm. thick, leafy; ligule a stramineous scale 2-3 mm. long centrally and with 
long auricles laterally; blades 15-37 cm. long, 7-14 mm. broad near the middle, 
tapering to both ends, flat; panicles 15-32 cm. long, ellipsoidal, the numerous 
branches ascending or rarely spreading, densely-flowered; zone of abscission just 
below the glumes; spikelets one-flowered, falling as a unit, strongly laterally 
compressed, with keeled scales; first glume 4-4.5 long; second glume 5-5.5 mm. 
long; lemma 5.5-6 mm. long, bearing dorsally just below the tip a minute awn 
equaling the tip of the lemma (use lens). 

Moist usually sandy soil, floodplains and stream banks in forests, in wet 
meadows and along sluggish streams, in Okla. (Sequoyah Co.) and e. Tex., infre- 
quent, Aug.-Sept.; all of e. U. S. w. to S. D., Neb., Kan., Okla. and Tex. 

234 




Fig. 110: 1, Cinna ariindinacea: plant, X i/^; glumes and floret, X 10. 2, Cinna 
latijolia: panicle, X 1; glumes and floret, X 10. (From Hitchcock & Chase). 



2. Cinna latifoiia (Trev.) Griseb. Fig. 110. 

Rhizomatous perennial 7-20 dm. tall; sheaths glabrous to finely scabridulous; 
ligules pubescent, 3-8 mm. long, erose and intact or usually more or less strongly 
lacerate; blades flat, 7-15 mm. wide, the veins very unequal in size; panicle 
15-30 cm. long, loose, the branches spreading to drooping; glumes slender, 
acuminate, (2-) 3-4 mm. long, the second somewhat the longest, scabridulous- 
puberulent on the keel and often over the back; lemma strongly compressed, 
2-3.2 mm. long, puberulent over the back, awnless or awned, the subterminal 
awn scarcely to 1 mm. long; palea almost as long as the lemma; rachilla bristlelike, 
mostly about 0.6 mm. long; anthers about 1 mm. long; lodicules cuneate-obovate, 
dentate, about 0.3 mm. long. 

In wet meadows, and wet soil along streams, and moist or wettish woods, in 
N. M. (Bernalillo Co.); Nfld. and Lab. to Alas., s. to N. C, Tenn., N.M. and 
Calif.; n. Euras. 

29. Alopecurus L. Foxtail 

Annuals or perennials; blades flat; panicles dense, straight, spikelike; zone of 
abscission just below the glumes; spikelets falling as a unit, one-flowered, strongly 
laterally compressed; glumes equal, united by the margins basally, keeled dorsally; 
lemma about as long as glumes, the margins united to each other basally, bearing 
an awn dorsally below the middle, this once-geniculate, the lower portion twisted; 
palea absent. 

About 50 species in temperate Eurasia, North America and South America. 

1. Spikelets 5-6 mm. long; introduced species 1. A. myosuroides. 

1. Spikelets 2-4 mm. long; native species (2) 

2(1). Awns straight, included or only slightly longer than the glumes; perennial 
2. A. aequalis. 

2. Awns geniculate, twisted below, much longer than the glumes (3) 

3(2). Perennial; anthers 1.5 mm. long 3. A. geniculatus. 

3. Annual; anthers about 0.5 mm. long 4. A. carolinianus. 

1. Alopecurus myosuroides Huds. 

Tufte-^ annual; culms 2-7 dm. long, 1.5-3 mm. thick, erect or the lower few 
internores reclining; ligule a scale 2-4 mm. long; blades 5-30 cm. long, 3-7 mm. 
broad, flat; spike 5-11 cm. long, 5-10 mm. thick; glumes 6-7 mm. long, the keel 
merely scabrous, not ciliate except basally; awn of lemma 5-8 mm. long. 

Moist or wet meadows in e. Tex., occurring only as waif brought in with hay. 
May; Euras., adv. and widespread in n.e. U. S.; also Wash, and Ore. 

Other European species are to be expected in our area as introductions, notably 
A. pratensis L., the meadow foxtail, rather similar to A. myosuroides but perennial 
and the keels of the glumes ciliate. 

2. Alopecurus aequalis Sobol. Short-awn foxtail. Fig. 111. 

Perennial; culms erect or somewhat decumbent below and rooting at the nodes, 
glabrous, 2-6 dm. tall (or taller in some aquatic forms); sheaths glabrous, usually 
somewhat inflated; ligules 3-5 mm. long; blades slightly scabrous, 1-4 mm. wide, 
sometimes tufted at base; panicles more or less exserted, narrow-cylindric, 2-7 
cm. long, 4-5 mm. wide; glumes 2-2.5 mm. long, ciliate on the keel, appressed- 
pubescent on the sides, especially below; lemma glabrous, the awn attached at or 
slightly below the middle, straight or slightly bent, included or exserted about 
1 mm.; anthers about 1 mm. long. 

In mud and shallow water of ponds, sloughs, lakes and streams, swampy ground, 
marshy areas, bogs, in N. M. (Lincoln, San Miguel, Taos, San Juan, Rio Arriba, 
McKinley, Socorro and Grant cos.) and Ariz. (Coconino, Apache and Yavapai 

236 




Fig. Ill: Alopecurus aequalis: a, floret, the lemma bearing an awn below the 
middle, X 12; b, habit, showing short basal leaves, the tall culms and narrow-cylindric 
panicles, X %; c, spikelet, showing the ciliate glumes, the awn of lemma protruding, 
X 12; d, grain, X 12; e, floret, variation in the awn of lemma, X 12; f, leaf sheath, 
ligule and scabrous blade, X 4. (From Mason, Fig. 57). 



COS.); Greenl. to Alas., s. to Pa., 111., Kan., N.M., Ariz, and Calif.; Euras. 

3. Alopecurus geniculatus L. Water foxtail. Fig. 112. 

Perennial; culms decumbent or long-decumbent at base, rooting at the lower 
nodes, glabrous, often bent above (only erect in dwarf forms), 1-6 dm. long above 
the rooting base; sheaths glabrous, usually somewhat inflated; ligules usually 
2-4 mm. long; blades minutely scabrous above, 1-4 mm. wide; panicles 2-7 cm. 
long, 4-6 mm. wide; glumes 2.5-3 mm. long, the tips often purplish, ciliate on 
the keel, glabrous or appressed-pubescent on the lateral margins; lemma glabrous, 
the often purplish awn bent, exserted about the length of the spikelet or farther; 
anthers about 1.5 mm. long. 

In mud and shallow water of lakes, ponds and waterways, and in marshes, in 
N. M. (Grant Co.) and Ariz. (Apache, Coconino. Santa Cruz, Yavapai and Pima 
COS.); Nfld. to Sask. and B. C, s. to Va., Pa., Mich., Wise, Kan., Wyo., N. M., 
Ariz, and Calif.; Euras. 

4. Alopecurus carolinianus Walt. 

Tufted annual; culm 1-5 dm. long, 1-2 mm. thick, the lower internodes com- 
monly not erect, the remainder erect; ligule a scale 1-3 mm. long; blades 2-15 cm. 
long, 1.5-5 mm. broad, flat; spikes 2-5 cm. long, 4-6 mm. thick; glumes 2-2.5 
mm. long, densely ciliate on the keels; awn of lemma 3-5 mm. long. 

Moist soil near ponds and streams, wet meadows, in Okla. (Johnston Co.), e., 
s.e. and n.-cen. Tex., infrequent and rare w. to Bexar, Burnet, Llano and Wichita 
COS., N. M. (San Miguel Co.) and Ariz. (Coconino, Gila and Pima cos.), Mar.- 
May; B. C. and practically throughout the U. S. except n. N.E. 

30. Polypogon Desf. 

Annual or perennial usually decumbent herbs; blades flat, scabrous; lower 
internodes reclining on mud, the nodes with adventitious roots; panicles dense; 
zone of abscission below the glumes; glumes nearly equal, both persistent, awned, 
united at the very base, scabrous or pubescent; lemma much shorter than glumes, 
involute, ellipsoidal, with a dorsal readily deciduous awn; palea membranous, 
enclosed by the lemma. 

A genus of about 15 species in warm regions of the world. 

1. Annual; glumes minutely lobed, the very slender awns (4-) 6-8 mm. long; 
panicles very dense, spikelike 1. P. monspeliensis. 

1. Perennials; glumes not lobed, the awn not more than 5 mm. long; panicles 

moderately dense (2) 

2(1). Glumes abruptly narrowed above, the awns 2.5-5 mm. long 

2. P. interruptus. 

2. Glumes gradually tapering into a short awn that is 1-2 mm. long 

3. P. elongatus. 

1. Polypogon monspeliensis (L.) Desf. Rabbitfoot grass. Fig. 113. 

Annual; culms often rooting at the lower nodes or less commonly totally erect, 
1-7 dm. long, 1-3 mm. thick; ligule a scale 3-10 mm. long; blades 4-16 cm. long, 
2.5-11 mm. broad, flat; panicle 2-15 cm. long, 1-2 cm. thick, either narrow and 
spikelike or broader and ellipsoidal and somewhat interrupted, stramineous at 
maturity; glumes 2 mm. long, apicaliy notched and in the notch each bearing an 
awn 5-9 mm. long; lemma less than 1 mm. long, with a deciduous awn less than 
1 mm. long. 

Moist soil near fresh water, in brackish ponds, seepage and boggy areas, 
marshes, wet meadows and along streams, throughout most of our region, scattered 
and local, Mar.-July; Eur., introd. and now widespread in temp. N. A.; of local 
forage value. 

238 





Fig. 112: Alopecurus geniculatus: a, habit, showing the cylindric panicles, the awns 
of lemmas conspicuous, X %; b, floret, showing the long curved awn of lemma attached 
below the middle, X 12; c, leaf sheath, ligule and scabrous blade, X 4; d, spikelet, 
showing the cilitate glumes and the long awn of lemma, X 12. (From Mason, Fig. 58). 



2. Polypogon interruptus H.B.K. Ditch polypogon. Fig. 113. 

Perennial; culms rooting at the lower nodes, 2-10 dm. long, 1-4 mm. thick; 
ligule a scale 4—10 mm. long; blades 4-22 cm. long, 2-12 mm. broad; panicle 
3-20 cm. long, 1-5 cm. thick, occasionally narrowed and somewhat spikelike but 
usually broad, interrupted, with whorled branches 1-5 cm. long; glumes 2 mm. 
long, apically entire, each bearing an awn about 2 mm. long; lemma a little longer 
than 1 mm. with a deciduous awn 2-3 mm. long. 

Calcareous mud along streams and irrigation ditches and low wet places, in 
Okla. (Waterfall) and on Tex. Edwards Plateau, rare (known only from Val 
Verde Co.), to Ariz. (Apache, Navajo, Coconino, Santa Cruz and Pima cos.), Apr.; 
widespread in temp. N. A. and S. A., n. to B.C. and Neb. 

3. Polypogon elongatus H.B.K. Fig. 1 14. 

Perennial; culms erect or often decumbent at base, glabrous, rather stout, as 
much as 1 m. tall; sheaths glabrous, somewhat nerved, lacerate at the rather 
broad summit, to 8 mm. long; blades scabrous on the margins, glabrous or some- 
what scabrous on the surfaces, to 20 cm. long and 1 cm. wide; panicle erect, in 
ours rather dense and spikelike but somewhat interrupted in the lower part, 
15-30 cm. long, the branches closely flowered to base; glumes hispidulous 
(especially on keel), 2-3 mm. long, gradually narrowed to an awn 2-3 mm. 
long; lemma 1.5 mm. long, the awn arising from below the tip, 1-2 mm. long or 
sometimes obsolete. 

In salt marshes, along streams and ditches, in Ariz. (Santa Cruz and Pima cos.); 
also Mex. to Arg. 

31. Phleum L. 

Annuals or perennials with erect culms, flat blades and dense cylindric panicles; 
spikelets 1 -flowered, laterally compressed, disarticulating above the glumes; glumes 
equal, membranaceous, keeled, abruptly mucronate or awned or gradually acute; 
lemma shorter than the glumes, hyaline, broadly truncate, 3- to 5-nerved; palea 
narrow, nearly as long as the lemma. 

A genus of 15 species in temperate Eurasia, North America and South America; 
probably all Eurasian in origin. 

1. Culms mostly more than 5 dm. tall, erect from a swollen bulblike base; panicle 
narrow, several times longer than wide 1. P. pratense. 

1 . Culms 2-5 dm. tall, from a decumbent somewhat creeping base; panicle 
usually not more than twice as long as wide, bristly.. ..2. P. alpinum. 

1. Phleum pratense L. Timothy. Fig. 1 15. 

Perennial from very short bulbously thickened rhizomes; aerial culms 5-10 dm. 
long, 2-3 mm. thick, the lowest internodes often reclining, otherwise erect, leafy; 
ligule a thin scale 2-4 mm. long; blades 6-26 cm. long, 5-10 mm. broad, tapered 
to a long point, flat; panicle 5-20 cm. long, 5-8 mm. thick, terete, spikelike; 
spikelets 1 -flowered, strongly laterally compressed; glumes equal 3-3.5 mm. long, 
oblong, hyaline but each with a firm keel prolonged into a short spreading awn, the 
keel ciliate; zone of abscission between the glumes and the lemma; lemma and 
palea about half as long as the glumes, hyaline, the palea very narrow. 

Occasional as a waif in marshes, wet meadows, seepage areas and in mud along 
streams, in the e. half of Tex., not persisting, brought in with hay, and N. M. 
(Colfax, Otero, Santa Fe, San Miguel and Sandoval cos.) and Ariz. (Coconino and 
Apache, s. to Graham and Pima cos.), summer; widespread in moist temp, parts 
of N. A., introd. from Euras. 

2. Phleum alpinum L. Alpine timothy. Fig. 1 15. 

Culms 2-6 dm. tall, glabrous, from a decumbent somewhat creeping densely 

240 




Fig. 113: 1, Polypogon monspeliensis: plant, X M>; glumes and floret, X 10. 2, 
Polypogon interruptus: panicle, X 1; glumes and floret, X 10. (From Hitchcock & 
Chase ) . 




Fig. 114: Polypogon elongatiis: a, spikelet, showing the hispidulous awned glumes, 
X 8; b, leaf sheath, ligule, and blade, X 4; c and d, upper parts of culms with spikelike, 
interrupted panicles, X i/r,; e, habit, lower part of plant, X I/5. (From Mason, Fig. 82). 



tufted base; blades mostly less than 15 cm. long, 3-6 mm. wide; panicle 1-5 cm. 
long or broadly cylindric; glumes 5 (sometimes 7) mm. long, oblong, hispid- 
ciliate on the keel, the stoutish awns 2 mm. long to give the head a bristly 
appearance. 

In wet mt. meadows, bogs, marshes and mud on edge of lakes and ponds, in 
N. M. (Rio Arriba, San Juan, Santa Fe, San Miguel and Taos cos.) and Ariz. 
(Apache and Coconino cos.); Greenl. to Alas., s. to N. H., Mich., N. M., Ariz, 
and Calif.; Euras. 

32. Gastridium Beauv, 
Two species in the Canaries, western Europe and the Mediterranean region. 
1. Gastridium ventricosum (Gouan) Schinz & Thell. Nit grass. Fig. 116. 

Plants annual; culms 1-5 dm. tall; foliage scant, the blades flat, scabrous; 
panicle 3-8 cm. long (or in robust specimens 10-14 cm. long), dense, shining, 
spikelike; spikelets 1 -flowered, slender, about 5 mm. long; glumes long-acuminate, 
somewhat swollen at the base, scabrous on the keels, the second glume about three- 
fourths as long as the first; lemmas much shorter than the glumes, hyaline, 
globular, pubescent, truncate, with a delicate, somewhat bent awn 5 mm. long; 
palea about as long as the lemma. 

Established usually on open, dry ground, but occasionally found in marshy 
sites along streams or around vernal pools, in Ariz. (Pima Co.); Ore. to Calif, 
and Ariz.; introd. from Eur. 

33. Muhlenbergia Schreb. Muhly 

Perennial or rarely annual low or moderately tall or rarely robust grasses, 
tufted or rhizomatous; culms simple or much-branched; inflorescence a narrow 
sometimes spikelike or open panicle; spikelets 1 -flowered or occasionally 
2-flowered, the rachilla disarticulating above the glumes; glumes usually shorter than 
the lemma or sometimes as long, obtuse to acuminate or awned, keeled or convex 
on the back, the first sometimes small or rarely obsolete; lemma firm-membranace- 
ous, 3-nerved with the nerves sometimes obscure or rarely an obscure additional 
pair, with a very short callus, rarely long-pilose, usually minutely pilose, the apex 
acute, awned from the tip or just below it or from between very short lobes, some- 
times only mucronate, the awn straight or flexuous. 

A genus of more than 100 species that occur from the Himalaya Mts. to Japan, 
and from North America to the Andes. The genus, as now interpreted, is very 
diverse, being a taxonomic dumping ground. Some of the muhlys are quite 
abundant and are valuable forage. 

1. Annuals (doubtful cases should be keyed under both alternatives) (2) 

1. Perennials (4) 

2(1). Lemma with awn 1-3 cm. long 2. M. pectinata. 

2. Lemma awnless (3) 

3(2). Pedicels capillary, elongate; glumes minutely pilose 1. M. minutissima. 

3. Pedicels short, appressed; glumes glabrous 3. M. filiformis. 

4(1). Rhizomes developed, usually prominent, scaly, creeping, often branching 
(5) 

4. Rhizomes wanting; culms tufted, usually erect (12) 

5(4). Blades 2 mm. wide or less, mostly short and involute (6) 

5. Blades flat, at least some of them more than 3 mm. wide, usually 5 mm. wide 

or more (8) 

243 




Fig. 115: 1, Phleum pratense: plant, X V>; glumes and floret, X 10. 2, Phleiim 
alpinum: panicle, X 1; glumes and floret, X 10. (From Hitchcock & Chase). 




Fig. 116: 1, Gastridium ventricosum: plant, X '1'; glumes and floret. X 10. 2, 
Muhlenbergio andina: plant, X 1; glumes and floret, X 10. 3, Muhlenbergia racemosa: 
panicle, X 1; glumes and floret, X 10. (From Hitchcock & Chase). 



6(5). Panicles open, the spikelets on slender pedicels 6. M. asperifolia. 

6. Panicles narrow, more or less condensed, the spikelets on short pedicels (7) 

7(6). Culms smooth, widely creeping, the blades fine, conspicuously recurved, 
spreading 4. M. utilis. 

7. Culms nodulose-roughened, erect or decumbent at base, sometimes spreading 

but not widely creeping 5. M. Richardsonis. 

8(5). Hairs at base of floret copious, as long as the body of the lemma 

7. M. andina. 

8. Hairs at base of floret inconspicuous, not more than half as long as the lemma 

(9) 

9(8). Glumes with stiff scabrous awn-tips, much-exceeding the awnless lemma; 
panicles terminal on the culm or leafy branches, compact inter- 
rupted, bristly 8. M. racemosa. 

9. Glumes acuminate, sometimes awn-tipped but not stiff and exceeding the 

lemma; panicles terminal and axillary, numerous, not bristly (10) 

10(9). Culms glabrous below the nodes; panicles not compact, the branches 
ascending; plants sprawling, top-heavy, the branchlets geniculate- 
spreading 9. M. frondosa. 

10. Culms strigose below the nodes; panicles compact or (if not) the branches 

erect or nearly so; plants often bushy-branching but not sprawling 
with geniculate branchlets (11) 

11(10). Panicles not compactly flowered; lemma with awn as much as 1 cm. 

long or more; some of the blades 1-1.5 dm. long or more 

10. M. sylvatica. 

11. Panicles compactly flowered or (if not) lemma awnless; blades commonly 

less than 1 dm. long but sometimes longer 11. M. mexicana. 

12(4). Culms decumbent and rooting at the nodes 12. M. Schreheri. 

12. Culms erect or spreading but not rooting at nodes 3. M. filiformis. 

1. Muhlenbergia minutissima (Steud.) Swall. Fig. 117. 

Tufted annual; culms 10-35 cm. long, 0.4-1 mm. thick, geniculately branched 
near the base; ligule a hyaline soon lacerate scale about 2 mm. long, not auricled; 
blades 3-10 cm. long, 1-2 mm. broad, usually flat, folded or involute on drying, 
minutely pubescent; panicles 1-2 dm. long, 2-3 cm. broad, open and diffuse, the 
numerous main branches often flexuous, ascending, much-branched secondarily; 
glumes 0.6-1 mm. long, minutely pubescent (use strong lens); lemma 1.2-2 mm. 
long, very finely pubescent, broadly elliptical, blunt or apically minutely bifid, awn- 
less or with an awn to about 1 mm. long; palea about equaling lemma. M. texana 
Buckl., M. sinuosa Swall. 

Rocky grassy slopes, border of marshes and wet canyon walls, in the Tex. 
Trans-Pecos (Davis Mts.), rare, N. M. (Hitchcock) and Ariz. (Apache, Navajo, 
Coconino, Yavapai, Gila and Pima cos.), late summer-fall; Mont, to Wash, and 
s. to Mex. 

2. Muhlenbergia pectinata C. O. Goodd. 

Culms 1-2.5 dm. tall or long, erect to decumbent, sometimes rooting at the 
lower nodes, freely branching, angular; sheath margins often ciliate; ligule erose 
to ciliate, about 0.5 mm. long; blades flat to involute, 1-6 cm. long, 1-2 mm. 
wide, pubescent or sparsely pilose; panicles numerous, narrow, 2-12 cm. long; 
spikelets 3.5-4.5 mm. long; glumes abruptly acute to acuminate, commonly 
aristate, 1.5-2 (-3) mm. long, the awn about half the entire length; lemma 3- to 
5-nerved, scabrous to prominently ciliate on the lateral nerves, the callus appressed- 
pubescent; awn 1-3 cm. long. 

246 




Fig. 117: Muhlenbergia minutissima: plant, X 1; spikelet, floret and ligule, X 10. 
(From Hitchcock & Chase). 



In wet places below or on face of cliffs, moist or wettish rocky hills, in Ariz. 
(Cochise and Santa Cruz cos.); also Jal. 

3. Muhlenbergia filiformis (Thurb.) Rydb. Pull-up muhly. 

Perennial or sometimes apparently annual, with fibrous roots or decumbent 
creeping bases; culms tufted, erect or somewhat spreading, glabrous, filiform, 
usually 0.5-1.5 dm. or sometimes as much as 3 dm. tall; ligules thin, hyaline, 
1-2 mm. long; blades flat, glabrous beneath, scabrous-pubescent on the upper 
surface, 1-3 cm. long, 1 mm. wide; panicles numerous, narrow, interrupted, few- 
flowered, usually less than 5 cm. long; glumes ovate, about equal in size, obtuse 
or acutish, awnless, 1 mm. long; lemma lanceolate, acute, 2 mm. long, mucronate, 
minutely pubescent, minutely scabrous at the tip, 1 mm. long, the callus glabrous. 

In wet meadows, springy or seepage areas, old lake beds and moist open woods, 
in N. M. (Hitchcock) and Ariz. (Apache and Coconino cos.); S. D. and Kan. to 
B. C, s. to N. M., Ariz, and Calif. 

4. Muhlenbergia utilis (Torr.) Hitchc. Aparejo muhly. 

Perennial from firm creeping rhizome; culms 1-3.5 dm. long; ligule a scale 
0.5—1 mm. long; blades 15-35 mm. long, about 1 mm. broad and mostly involute, 
the smaller blades 5-20 mm. long and closely involute and arcuate, 0.2-0.4 mm. 
thick as rolled; glumes 0.6-1.5 mm. long; lemma 1.6-2 mm. long, scarcely 
mucronate. 

Calcareous seasonally muddy soil along streams, marshy places and about 
springs in the Tex. Edwards Plateau, N. M. (widespread in s. half) and Ariz. 
(Santa Cruz Co.), locally abundant, usually fall-early winter, occasionally spring- 
summer; also Calif, and Nev. 

5. Muhlenbergia Richardsonis (Trin.) Rydb. Mat muhly. 

Perennial from numerous hard creeping rhizomes; culms wiry, nodulose- 
roughened, erect or decumbent at base, 1-6 dm. tall; ligule 2-3 mm. long; blades 
usually involute, 1-5 cm. long or rarely longer; panicle narrow, interrupted or 
sometimes rather close and spikelike, 2-10 cm. long; spikelets 2-3 mm. long, the 
glumes about half as long, ovate; lemma lanceolate, acute, mucronate. 

In wet meadows, dry or wettish often alkaline soils and low open ground, 
in Ariz. (Coconino Co.); N. B. to Alta., s. to S.D., N. M., Ariz., Calif, and 
Baja Calif. 

6. Muhlenbergia asperifolia (Nees & Mey.) Parodi. Scratchgrass muhly. 

Perennial from elongate scaly rhizomes 1.5-2 mm. thick; aerial culms 1-6 dm. 
long, about 1 mm. thick, mostly weak and reclining, ascending only at the flori- 
ferous ends, sparsely branched; ligule a muticous scale about 0.5 mm. long, not 
auricled; blades 2-7 (-14) cm. long, 1-3 mm. broad, flat or folded, mostly rapidly 
ascending; panicle 5-18 cm. long, 4-15 cm. broad, ovoid, very open, diffuse, few- 
flowered; glumes 0.6-1 (rarely to 1.5) mm. long, acute; lemma 1.2-1.5 mm. long, 
dark, awnless; palea about equaling lemma. 

Moist alluvial soil near streams and ditches, occasional in marshy, wet, or 
often alkaline soil, in water of cat-tail swamps and mud about pools and lakes, 
in w. Okla. {Waterfall) and the Tex. Plains Country and Trans-Pecos, N. M. (San 
Juan and Valencia cos.) and Ariz. (Apache to Coconino, s. to Pima cos.) 
infrequent, late summer-fall; w. N. A. e. to 111., Okla. and Tex.; s. S. A. 

7. Muhlenbergia andina (Nutt.) Hitchc. Foxtail muhly. Fig. 116. 

Perennial from scaly white rhizomes 1-2 mm. thick; aerial culms 25-80 cm. 
long, 1-1.5 mm. thick, erect, leafy, sparingly branched; ligule a scale about 1 mm. 
long, laterally with very short auricular points; blades 5-18 cm. long, 1-3 mm. 
broad (rarely to 5 mm.), flat; panicle 4-12 cm. long, 6-15 mm. thick, spikelike 

248 



but usually interrupted; glumes 3-4 mm. long, shining, grayish, keeled, awnless; 
lemma 2-3 mm. long, linear, grayish, glabrous but with a basal callus bearing a 
beard of hairs 2-3 mm. long and an apical awn 4-8 mm. long; palea nearly 
equaling lemma. 

In wet meadows, moist thickets and river beds, in the (?) Tex. Trans-Pecos 
and N. M. (San Miguel Co.); w. U.S., e. to Wyo., Colo., N.M. and possibly Tex. 

8. Muhlenbergia racemosa (Michx.) B.S.P. Fig. 116. 

Perennial from scaly white rhizomes 1-2 mm. thick; aerial culms 3-7 dm. long, 
0.5-2.5 mm. thick, erect, leafy, sparingly branched; ligule an erose scale 0.5-1 mm. 
long, without auricles; blades 4-16 cm. long, 1-7 mm. broad, flat, rather stiffly 
erect; panicles 2-14 cm. long, 4-11 mm. thick, spikelike but usually interrupted; 
glumes 1.5-2 mm. long, lanceolate, apically with a stiff awn 2-5 mm. long; lemma 
2.5-3.5 mm. long, short-pilose on the lower half, acuminate or the apical portion 
awnlike; palea nearly equaling lemma. 

Moist ground, wet meadows, swamps, alluvial soil along rivers, streams and 
irrigation ditches, in Okla. (Waterfall) and the Tex. Plains Country, rare (one 
collection from Perryton, Ochiltree Co.), N. M. (widespread) and Ariz. (Apache 
and Coconino cos.), Sept.-Oct.; most of U. S. w. of Miss. River. 

9. Muhlenbergia frondosa (Poir.) Fern. Wirestem muhly. 

Perennial from scaly white rhizomes 1-2 mm. thick; aerial culms 3-10 dm. 
long, 1-2 mm. thick, leafy, profusely geniculately branched near the middle, top- 
heavy and falling over (then often rooting at the nodes), the naked pedunculiform 
terminal internodes only 1-4 cm. long or absent; ligule an erose scale 0.5-1 mm. 
long, not auricled; blades 4-11 cm. long, 1.5-5 mm. broad, flat, ascending or 
appressed; panicles 3-10 cm. long, when only 1-2 mm. thick then linear but 
when 3-6 mm. thick tapered to both ends, loose and interrupted; glumes 2.5-3.5 
mm. long including the awnlike tip, linear-lanceolate; lemma about 3 mm. long, 
awnless, pubescent on the lower part; palea about 3 mm. long. 

Woods, sandbars along streams, muddy banks of streams and swales, low wet 
soils and thickets, in Okla. [Waterfall) and n.-cen. Tex., rare (Dallas and Grayson 
cos.) Oct.; e. Can. s. to n. Ala., Tex. and Okla. 

10. Muhlenbergia sylvatica (Torr.) Torr. 

Perennial from scaly rhizomes 1-2.5 mm. thick; aerial culms 4-10 dm. long, 
1-3 mm. thick, leafy, moderately branched near the middle, weak and often 
reclining, the lower nodes rooting, the internodes minutely strigose in a zone just 
below the nodes (use lens), the terminal internodes short and not pedunculiform; 
ligule an erose scale 0.5-1.2 mm. long; blades 6-18 cm. long, 2-7 mm. broad, 
flat, ascending; panicles 4-10 cm. long, 3-5 mm. thick, somewhat spikelike, 
interrupted, nodding; glumes about 2 mm. long, awnless or with an awnlike tip 
0.1-1 mm. long; lemma about 3 mm. long, pubescent in the lower part, with 
an awn 3-10 mm. long; palea about 3 mm. long. 

Dense woods and swampy meadows, in Okla. (Waterfall) and n.-cen. Tex. and 
e. Edwards Plateau, rare, Aug -Sept.; s.e. Can. s. to n. Ala. and Tex. 

11. Muhlenbergia mexicana (L.) Trin. 

Resembling M. frondosa: culms erect or ascending, usually simple below, less 
freely branching, scaberulous below the nodes; blades lax, 1-2 dm. long, mostly 
2-4 mm. wide; panicles mostly long-exserted, narrow, the upper often 10-15 cm. 
long, of numerous short appressed densely flowered somewhat aggregate branches; 
spikelets 2-3 mm. long; glumes narrow, attenuate, awn-tipped, about equaling 
the pointed or awn-tipped lemma, the lemma long-pilose below. 

249 



In wet meadows, swales, springy places along streams and about pools, damp 
thickets and wettish low open ground, in N. M. (San Miguel and Socorro cos.) 
and Ariz. (Cochise Co.); Me. and Que. to Wash., s. to N. C, Ark., N.M. and 
Ariz. 

12. Muhlenbergia Schreberi J. F. Gmel. Nimblewill muhly. 

Perennial with stolons about 1 mm. thick, freely rooting; flowering culms 1-4 
dm. long, 0.5-1 mm. thick, weak, ascending; ligule an erose scale about 0.5 mm. 
long, not auricled; blades 3-8 cm. long, 1-4 mm. broad, weak, flat, diverging 
from culm at right angles; panicles 5-12 cm. long, 1-3 mm. thick, spikelike but 
lax and interrupted, weak and nodding; glumes minute, 0.1-0.3 mm. long, muti- 
cous; lemma about 2 mm. long, linear-lanceolate, with an awn 1.5-6 mm. long; 
palea about 2 mm. long. 

Moist usually shaded ground near streams and marshy areas, wet meadows 
and wet sandy-clay about ponds, in Okla. (Waterfall) and e., s.e. and n.-cen. 
Tex. and e. Edwards Plateau and n. Rio Grande Plains, scattered but locally 
abundant, spring-fall; e. U.S., w. to Neb., Kan., Okla. and Tex. 

34. Sporobolus R. Br. Dropseed 

Perennials (except in 1 species); inflorescences paniculate, either open and dif- 
fuse or spiciform; spikelets 1 -flowered, slightly laterally compressed, with mem- 
branous to scarious parts; rachilla with zone of abscission just above the glume 
node and below the lemma nodes in most species; palea often splitting at 
maturity; grain usually falling readily, often reddish, with a coat (ovary wall) 
that imbibes water, becoming loose and easily detached from the remainder of 
the grain. 

A genus of about 150 species of the warmer regions of the world. 

1. Mature panicles more than 9 cm. broad 1. S. texanus. 

1. Mature panicles less than 9 cm. broad (2) 

2(1). Collar of sheath (dorsal summit where it joins the blade) abundantly 
furnished with soft white hairs; panicle more than 2 cm. broad 
2. S. flexuosus. 

2. Collar of sheath glabrous (but the corners commonly pilose); panicle less 

than 1.5 cm. broad (3) 

3(2). Mature panicles less than 5 cm. long 3. S. virginicus. 

3. Mature panicles more than 5 cm. long 4. S. indicus. 

1. Sporobolus texanus Vasey. Fig. 118. 

Tufted perennial from short very firm rhizomes 1.5-2 mm. thick, or these 
often apparently absent; aerial culms numerous, 3-7 dm. long, 1-2 mm. thick, 
leafy; ligule a very dense line of cilia about 0.5 mm. long; blades 1-12 (-20) cm. 
long, 2-4 mm. broad near the base, flat or drying involute, pointed; summit of 
sheath glabrous but the corners and margins often sparsely long-pilose; panicle 
15-30 cm. long, 1-2 dm. broad, vaguely obovoid, open and diffuse, the branches 
not whorled but bearing numerous somewhat flexuous capillary ultimate branch- 
lets 5-20 mm. long, each terminating in a single spikelet; first glume 0.7-1.5 mm. 
long; second glume 2.1-2.8 mm. long; lemma 2.3-2.9 mm. long; palea about 
equaling lemma. 

Seasonally moist and often subsaline low areas, salt marshes, mesas and valley, 
in Okla. (Waterfall), the Tex. Plains Country and Trans-Pecos, infrequent or 
rare, N.M. (Chaves and Eddy cos.) and Ariz. (Coconino Co.), summer-fall; w. 
Kan. to Tex. and w. to Ariz. 

250 




Fig. 118: 1, Sporobohis indicus: plant, X V-r, spikelet and floret, X 10. 2, Sporobolus 
texanus: panicle, X V^; glumes and floret with caryopsis, X 10. (From Hitchcock & 
Chase). 



2. Sporobolus flexuosus (Thurb.) Rydb. Mesa dropseed. 

Tufted perennial; culms 3-10 dm. long, 1-2 mm. thick, erect, unbranched; 
ligule a ciliate fringe 0.3-0.5 mm. long; blades 5-23 cm. long, 2.4 mm. broad at, 
the base where flat but usually soon involute; sheaths obscurely round-keeled 
apically, the corners with some soft white hairs but the dorsal summit or collar 
glabrous or only very sparsely furnished with hairs, 1-1.5 mm. long; panicles 
12-30 cm. long, 4-9 cm. broad, basally sometimes partially included in the 
uppermost sheath, open, the branches not whorled, divaricate or even somewhat 
deflexed and then arcuately reflexed distally, the floriferous branchlets subsecund 
on the lower side of the branches, mostly widely divergent from the branches, 
the spikelets borne on tertiary pedicellary branchlets about 1 mm. long which 
are subsecund along the proximal side of the secondary branchlets; first glume 
1-1.3 mm. long; second glume 1.9-2.5 mm. long; lemma 1.9-2.3 mm. long; 
palea about equaling lemma. 

Loose usually blowing sand in dune areas, also in marshes and wet seepage 
areas, in the Tex. Trans-Pecos, locally frequent, N. M. (widespread) and Ariz. 
(Apache, Navajo, Coconino, Yavapai, Graham, Cochise and Pima cos.), Sept.- 
Nov., rarely also in spring; w. Tex. to s. Ut., Nev., s. Calif, and n. Mex. 

3. Sporobolus virginicus (L.) Kunth. Coastal dropseed. 

Perennial from scaly creeping stramineous rhizomes 1-3 mm. thick; aerial 
culms mostly ascending or the lowermost internodes stoloniform, 7-40 cm. long, 
1-3 mm. thick, leafy; ligule a ciliate scale 0.2-0.4 mm. long; blades 3-20 cm. 
long, usually flat at the very base or rounded-keeled and 2.5-4 mm. broad, 
tapering to an involute point; corners of sheaths sparsely pilose and upper part 
of sheath dorsally keeled; panicle 25-80 mm. long, 6-10 mm. broad, dense, 
spikelike or usually narrowly ellipsoidal or oblong-ellipsoidal; first glume 1.3-2.8 
mm. long; second glume 1.8-3 mm. long; lemma 2.1-3 mm. long; palea about 
as long as lemma. 

Packed loamy somewhat saline soil, in saline marshes, sandy or muddy sea- 
shores and wettish coastal prairies, all along the Tex. coast, common, summer- 
fall; warmer Atl. and Carib. coasts, s. to Braz. and n. to Va. 

4. Sporobolus indicus (L.) R. Br. Smutgrass. Fig. 118. 

Tufted perennial; culms 3-1 1 dm. long, 1-3 mm. thick, erect, unbranched; 
ligule obsolete or only a scale 0.1 mm. long; blades aggregated at the base of 
the plant, 15-25 (-50) cm. long, at the base usually flat or sharply folded, 3-5 
mm. broad, tapering to a long involute arcuate tip; upper part of the sheaths 
usually dorsally keeled; panicles 1-4 dm. long, 5-10 mm. thick, dense, spikelike, 
often somewhat interrupted in the lower part; first glume 0.4-0.9 mm. long; 
second glume 0.8-1.3 mm. long; lemma 1.4-2 mm. long; palea 1.2-1.8 mm. 
long; pericarp mucilaginous, the grain often sticking persistently instead of falling 
readily as in many dropseeds. In some works erroneously called S. Poiretii. 

Mud and moist loam, low prairies and swales, in shallow water and mud 
about ponds and springy areas, in s.e. Okla. {Waterfall) and e. and s.e. Tex., 
s.w. to Bexar, DeWitt, Goliad and Aransas cos., frequent, late spring-Nov.; 
widely distributed in the warmer parts of the world, nat. to the Old World; in 
Am. occurring n. to Va., Tenn., Ark. and Okla. 

35. Leptochloa Beauv. Sprangletop 

Annuals; spikelets 3- to 12-flowered, the lower 1 or 2 florets perfect, the 
rest staminate or neutral; spikelets sessile and overlapping, appressed in two rows 
along one side of a nearly terete rachis (the rachis with its two rows of spikelets 
being called a "raceme," the total inflorescence being a panicle of 4 to 90 of 

252 



these racemes attached along an axis, the axis being elongate); zone of abscission 
just below each lemma, the marginal basal portion of the lemma pubescent or 
nearly glabrous. 

A genus of about 27 species in the warmer parts of the world. 

1. Lemma 1-1.5 mm. long (2) 

1. Lemma at least 1.8 mm. long (3) 

2(1). Panicles more than 10 times as long as broad; racemes stiffly ascending 
or appressed 4. L. Nealleyi. 

2. Panicles much less than 10 times as long as broad 5. L. filiformis. 

3(1). Recemes usually more than 40 per panicle; spikelets 3.5-4.5 mm. long; 
lemmas about 2 mm. long, acute 3. L. panicoides. 

3. Racemes usually fewer than 40 per panicle; spikelets 4-10 mm. long; lemmas 

1.8-4 mm. long (4) 

4(3). Lemmas lance-elliptic, acute and acuminate, 2.5-4 mm. long 

, 1. L. fascicularis. 

4. Lemmas obovate, blunt, 1.8-3 mm. long 2. L. uninervia. 

1. Leptochloa fascicularis (Lam.) Gray. Bearded sprangletop. Fig. 119. 
Tufted annual; culms 2-9 dm. long, 2-3 mm. thick, erect or geniculately 

ascending, sparingly branched, leafy, soft; ligule a hyaline scale 2.5-6 mm. long, 
usually lacerate into several strap-shaped parts, the lateral portions resembling 
auricles on the sheaths; blades 5-35 cm. long. 2-10 mm. broad, flat or soon 
involute; panicles 15-30 cm. long, 2-5 cm. broad, usually partly included in the 
sheath; racemes 14 to 35, widely spaced on the panicle axis but appressed or 
ascending and overlapping, 3-1 1 cm. long, 3-5 mm. thick; spikelets scarcely 
laterally compressed, overlapping, 5-10 mm. long, 6- to 12-flowered; glumes 
1.5-3.5 mm. long, acute; lemma lance-elliptic, 2.5-4 mm. long, acute or acumi- 
nate to mucronate or short-awned, pubescent near the margin in the lower half, 
the hairs conspicuous from the side of the spikelet under a lens. 

Muddy areas, sometimes alkaline or subsaline mud, brackish marshes, about 
playa lakes, in seepage areas, and in shallow water of ponds and streams, in 
Okla. (Logan and Pawnee cos.), in the Tex. Plains Country, Trans-Pecos, Rio 
Grande Plains, and n.-cen. and s.e. Tex., scattered but locally abundant, N. M. 
(Lea, Socorro, Dona Ana, Chaves and Eddy cos.) and Ariz. (Coconino, Navajo, 
Graham, Gila, Pinal, Cochise and Pima cos.) summer-fall; widespread in the 
warmer parts of the New World, n. to N. E., N. D. and Wash. (See remark under 
L. uninervia.) 

2. Leptochloa uninervia (Presl) Hitchc. & Chase. Fig. 120. 

Much like L. fascicularis, identical in habit; racemes 20 to 40, 2-8 cm. long; 
spikelets 4-9 mm. long; glumes and lemmas much less acute, the latter 1.8-3 mm. 
long, obovate and obtuse or muticous, sometimes mucronate, the pubescence in- 
conspicuous or hidden when spikelet is viewed from the side. 

Mud, sometimes alkaline or subsaline mud, in ditches, along and in sloughs 
and river sand bars, in Okla. (Love Co.) and in the Tex. Edwards Plateau, Rio 
Grande Plains, s.e. and Trans-Pecos Tex., to be expected in n.-cen. Tex. and the 
Plains Country, scattered, spring-summer, rarely into fall; widespread but scat- 
tered in the warmer parts of the New World n. to N. E., Okla., Colo., Ut. and 
Ore. Perhaps only a form of L. fascicularis. 

3. Leptochloa panicoides (Presl) Hitchc. 

Tufted annual; culms 5-10 dm. long. 2-6 mm. thick, erect, sparingly or not 
branched, leafy, soft; ligule a hyaline usually lacerate scale 2-4 mm. long; blades 
2-5 dm. long, 3-10 mm. broad, folded or drying involute: sheaths sharply keeled; 

253 




Fig. 119: Leptochloa fascicularis: a, floret, showing awned lemma with bifid apex, 
X 12; b, spikelets, X 8; c, grain. X 20; d, habit, showing the branching culms and the 
panicles X '/,; e, floret, showing palea, X 12; f, leaf sheath and fimbriate ligule, X 4. 
(From Mason, Fig. 73). 




Fig. 120: Leptochloa uninervia: a, spikelets, X 8; b and c, floret, showing palea 
and the apiculate lemma, the margins basally pubescent, X 16; d, habit, X %; e, grain, 
X 16; f, leaf sheath and the bilobed ligule, X 4. (From Mason, Fig. 74). 



panicles 1-2 dm. long, 3-6 cm. wide; racemes 40 to 90, crowded, ascending, 2-5 
cm. long, 2-3 mm. thick; spikelets laterally compressed, closely overlapping, 5- to 
7-flowered, 3.5-4.5 mm. long; glumes and lemma acute, about 2 mm. long, 
mucronate, pubescent laterally on the lower part. 

Mud, e. and s.e. Tex., rare, spring-fall; nat. of Braz.; Mo. to Miss., Ark. and 
Tex.; adv. in India. 

4. Leptochloa Nealleyi Vasey. 

Tufted annual; culms 5-15 dm. long, 1.5-6 mm. thick, erect, unbranched, 
leafy; ligule a somewhat lacerate scale 1-3 mm. long; blades 1-4 dm. long, 2-7 
mm. broad, flat or basally folded or drying involute; sheaths sharply keeled; pani- 
cles 2-5 dm. long, 1-3 cm. broad; racemes 25 to 85, overlapping, 1-10 cm. 
long, about 2 mm. thick, stiffly ascending or appressed; spikelets laterally com- 
pressed, closely overlapping, 3- or 4-flowered, 2-3 mm. long; glumes and lemmas 
about 1 mm. long, the former acute, the latter blunt and awnless with slightly 
pubescent nerves. 

Mud, near the coast, in marshes and in mud and water of sloughs, s.e. Tex. 
and Rio Grande Plains, scattered, spring-fall; coastal areas, Tam. to La. 

5. Leptochloa filifomiis (Lam.) Beauv. Red sprangletop. Fig. 121. 

Tufted annual; culms 2-9 dm. long, 1-3 mm. thick, geniculate and occasionally 
rooting at lower nodes, sparingly branched, ascending, leafy, soft; ligule a hyaline 
somewhat lacerate scale about 1 mm. long; blades 2-20 cm. long, 1.5-10 mm. 
broad, flat; sheaths papillose-pilose; panicles 7-35 cm. long, 2-21 cm. broad; 
racemes 7 to 70, remote, 1—15 cm. long, 1-2 mm. thick, diverging from axis 
at angles of 40°-90°; spikelets not much-compressed laterally, 1.4-2.6 mm. long, 
3- or 4-flowered, barely overlapping; glumes lanceolate, the second one sur- 
passing the lowest lemma; lemma blunt, 1-1.5 mm. long, awnless, pubescent on 
the nerves. 

Moist soil and mud, along streams, on flats, and alluvial banks, in Okla. 
(Waterfall) and in e., s.e. and n.-cen. Tex., Rio Grande Plains and rarely w. 
to e. Plains Country, scattered, in N. M. (Dona Ana and Sierra cos.) and Ariz. 
(Apache, Navajo and Coconino, s. to Cochise, Santa Cruz, Pima and Yuma cos.), 
late spring-fall; widely distributed in the warmer parts of the New World n. to 
Va., Ind., 111., Mo., Kan., N.M., Ariz, and Calif. 

36. Cynodon Rich. 

A genus of perhaps 10 species of the warmer parts of the Old World; one 
species now nearly ubiquitous in warmer parts of the whole world. 

1. Cynodon Dactylon (L.) Pers. Bermuda grass, pata de gallo. Fig. 122. 

Rhizomatous and stoloniferous perennial; aerial culms 1-4 (10) dm. long, 1-2 
mm. thick, the lower portions stoloniferous and much-branched, distal portions 
ascending; ligule a double fringe of cilia, a shorter denser fringe about 0.5 mm. 
long and sparser hairs 1-2 mm. long; blades 1-8 (-13) cm. long, 1-4 mm. 
broad, mostly flat or folded, ascending; sheaths pilose at the corners; panicles 
flabellate, of digitate spikes; spikes 3 to 7 (usually 4 or 5) per panicle, 1-6 cm. 
long, about 1 mm. thick, ascending; spikelets sessile, very crowded, 1 -flowered, 
1-5-2 (-2.5) mm. long, strongly compressed, arranged in 2 rows along and ap- 
pressed to one side of the very narrow rachis; glumes 1-1.5 mm. long, narrow, 
acute, persistent, the single nerve forming a keel; zone of abscission below the 
lemma; lemma 1.5-2 mm. long, awnless, slightly cartilaginous, pubescent on the 
dorsal keel, with lateral nerves very near the margin. C. inaritimm H.B.K. 

Loamy, usually alluvial, seasonally moist, sometimes alkaline or subsaline, 
soils, capable of surviving periodic submersion about hot springs, nearly through- 
out Tex. to Ariz. (Graham Co.), most abundant in the coastal areas of s.e. Tex. 

256 




Fig. 121: Leptochloa filiformis: a, spikelets on rachis, X 20; b, seed, X 20; c, leaf 
sheath and ligule, X 4; d, floret, X 20; e. habit, showing the long panicles and spread- 
ing-ascending spikes, X %. (From Mason, Fig. 72). 




Fig. 122: Cynodon Dactylon: plant, X I/2; spikelet and two views of floret, X 5. 
(From Hitchcock & Chase). 



and Rio Grande Plains, spring-fall and in the extreme s. in winter; nat. of Euras., 
introd. and ubiquitous in disturbed areas, warmer parts of Am. n. to N. E., 
Mich., la., Colo., Ut., Nev. and Ore. 

Very important as a forage in tame pastures, and as a lawngrass. 

37. Beckmannia Host. 

Two species confined to the North Temperate Zone. 

1. Beckmannia Sysigachne (Steud.) Fern. American slough grass. Fig. 123. 

Annual; culms light green, erect, rather stout, 3-10 dm. tall; blades flat; panicle 
10-25 cm. long, narrow, more or less interrupted; spikes crowded, 1-2 cm. 
long, appressed or ascending; spikelets 1 -flowered, laterally compressed, subcir- 
cular, nearly sessile and closely imbricate, in 2 rows along one side of a slender 
continuous rachis, disarticulating below the glumes, falling entire, 3 mm. long; 
glumes equal in size, inflated, obovate, 3-nerved, transversely wrinkled and with 
a deep keel; lemma narrow, 5-nerved, acuminate with the apex protruding beyond 
the glumes; palea nearly as long as the lemma. 

Marshy flats, ditches, swampy grounds, wet meadows, in mud of irrigated fields 
and edge of lakes and ponds, in N. M. (Rio Arriba, San Juan and Taos cos); 
Man. to Alas.; N. Y. and O. to Pac. Coast, s. to Kan. and N.M.; Asia. 

38. Spartina Schreb. Cordgrass 

Perennials; ligule a fringe of cilia; panicle of several spikes; zone of abscission 
at the base of the spikelet; spikelet strongly laterally compressed, very closely 
imbricate, arranged in 2 rows on the abaxial side of the flattened rachis of the 
spike, 1 -flowered, firm; glumes very unequal, the first shorter than the lemma, 
the second longer than the lemma; palea often longer than the lemma but shorter 
than the second glume. 

A genus of about 16 species, mostly American but a few on the coasts of 
Europe and Africa. 

These plants afford protection for wildlife in coastal and inland marshes. Their 
seeds are eaten by some species of ducks, marsh birds and songbirds, and the 
rootstocks also provide valuable winter food for geese. Muskrats are also known 
to feed on their underground parts. 

1. Spikelets 15-25 mm. long, including the awn; second glume with an awnlike 
tip a third to a half its entire length; keels of second glume and 
lemma with bristles 0.2-0.4 mm. long 6. S. pectinata. 

1. Spikelets 5-15 mm. long, awnless; keel of second glume and lemma often 

minutely pubescent but not pectinate (2) 

2(1). Spikes numbering only 2 to 7 (to 10) per panicle, often remote (the panicle 
axis being 9-20 cm. long); culms only 2-4 mm. thick and rhizomes 
present (3) 

2. Spikes more numerous per panicle and more crowded or if few then culms 

thicker and/ or rhizomes absent (4) 

3(2). Blades usually flat but becoming involute; glumes conspicuously hispid- 
ciliate on the keels; spikes 4 to 8, appressed 4. 5. gracilis. 

3. Blades usually involute; glumes scabrous on the keels; spikes 2 to several, 

ascending to spreading 5. S. patens. 

4(2). Spikes 1-3.5 cm. long; panicle spikelike, 5-10 mm. thick; rhizomes absent; 

leaf blades nearly wholly involute, 2-5 mm. broad at base 

1. S. spartinae. 

4. Spikes 4-15 cm. long; panicles 7-70 mm. broad; rhizomes present; leaf blades 

4-25 mm. broad at base, mosfly flat (5) 

259 




Fig. 123: Bcckmcinnia Syziiiachnc: a, panicle, showing the ascending spikes, X %; 
b, habit, X Vs; c, floret, X 12: d, spikelet, laterally compressed, X 8; e, grain, X 12; 
f, leaf sheath and ligule, X 4. (From Mason, Fig. 59). 





e N 



Fig. 124: Spartina spartinae: a, basal part of plant, X 1^2; b, middle section of plant, 
X 1/2; c, upper part of plant, X Vr, d, ligule, X 2; e, spikelet, X 6. (Courtesy of R. K. 
Godfrey). 



5(4). Panicle mostly less than 3 cm. broad: spikes only 5 to 30 per panicle; 

rhizomes soft; culms 6-15 dm. long 2. S. altemiflora. 

5. Panicle mostly more than 3 cm. broad; spikes usually 25 to 45 per panicle; 

rhizomes firm; culm firm and tough, 9-30 dm. long 

3. 5. cynosuroides. 

1. Spartina spartinae (Trin.) Hitchc. Sacahuista, Gulf cordgrass. Fig. 124. 

Tufted perennial; lowermost internodes occasionally shortly subrhizomatous 
toward the outside of the large tuft but true rhizomes absent; culms numerous, 
5-20 dm. long, 2.4 mm. thick, erect, unbranched; ligule 1-2 mm. long; blades 
2-7 dm. long, 2-5 mm. broad at the base, closely involute essentially the entire 
length, the tips sharp and spinelike; panicle spikelike, 6-40 cm. long, 5-9 mm. 
thick, usually tapered to both ends; spikes 10 to 75 per panicle, 10-35 mm. long, 
3-4 mm. thick, closely appressed and overlapping; spikelets 16 to 40 per spike, 
5-8 mm. long; first glume 2-6 mm. long; second glume 4-8 mm. long; lemma 
about equaling second glume; keels of glumes and lemma minutely hispid. 

Abundant in tight loamy somewhat saline poorly drained flats, marshes, swamps 
and wet coastal prairies, in s.e. Tex. and Rio Grande Plains, extremely abundant 
near the coast, rare and scattered inland (e.g. Gonzales Co.), spring-summer, 
rarely fall; Gulf and Carib. shores, U.S., Mex. and C.A.; also inland in S.L.P., 
Coah. and N. L.; also inland in Arg. and Parag. 

The young shoots emerging after fires are good forage but the older shoots 
are much too tough even for horses. Formerly vast acreage of sacahuista were 
therefore burned over purposely in the ranches of southern Texas; the practice 
is less common now. 

2. Spartina altemiflora Lois. Smooth cordgrass. Fig. 125. 

Perennial from relatively soft deeply buried (and seldom collected) branched 
rhizomes 4-7 mm. thick; aerial culms 6-15 dm. long, 3-14 mm. thick, erect, 
unbranched, leafy; ligule 1-2 mm. long; blades 20-55 cm. long, 4-16 (-25) mm. 
broad at the very base, flat, distally involute and wholly involute on drying; pan- 
icle 1-4 dm. long, 7-22 mm. thick, tapered to both ends, somewhat spikelike but 
lax; spikes 5 to 30 per panicle, 4—10 cm. long. 3-5 mm. thick, appressed or usually 
diverging at angles of 10°-20°, closely overlapping; spikelets 10 to 40 per spike, 
8-14 mm. long; first glume 4-10 mm. long; second glume as long as spikelet, the 
lemma a little shorter; keels of glumes and lemma with some minute pubescence. 
Incl. \ SIT. glabra (Muhl.) Fern. 

Abundant in colonies at the tidally-innundated shores of brackish to hypersaline 
bays and river-mouths, along the Tex. coast, locally common, summer-fall; nat. to 
the e. coast of N.A. from the Maritime Provinces to Tex., and also S.A. from 
Qui. to Arg.; introd. in Wash., and in Fr. and Eng. 

3. Spartina cynosuroides (L.) Roth. Big cordgrass. Fig. 126. 

Perennial from deeply buried (rarely collected) rhizomes 7-15 mm. thick; 
aerial culms 9-30 dm. long, 4-25 mm. thick, erect, unbranched, leafy; ligule 1-3 
mm. long; blades 25-70 cm. long. 10-22 mm. broad at base, flat, at the tip in- 
volute; panicle 15-30 cm. long, 4-7 cm. broad, more or less ellipsoidal; spikes 5 
to 67 (usually 25 to 45) per panicle, 5-15 cm. long, 3-6 cm thick, basally shortly 
naked, usually diverging at angles of 20°-30°, overlapping; spikelets 30 to 70 per 
spike, 9-14 mm. long; first glume 3-7 mm. long; second gUime as long as spikelets, 
the lemma a little shorter; glumes and lemmas minutely pubescent on the keels or 
wholly glabrous. 

Locally abundant in colonies in muck at tidally submerged shores of brackish 
bays and river-mouths, also in marshes, in s.e. Tex. (Chambers. Galveston and 
Harris cos.), summer; coasts from Mass. to Tex. 

262 




Fig. 125: Spardna alternifolia: a, basal part of plant, X i/^; b, section of center of 
plant, X V>; c, top of plant, X V2; d, ligule, X 4; e, spikelet, X 5. (Courtesy of R. K. 
Godfrey). 




Fig. 126: Spartina cynosurohics: a, basal part of plant, X ^'x, b, lower center sec- 
tion of stem, X Mj; c, upper center section of stem, X 1/3; d, inflorescence, X %; e, ligule, 
X 1; f, spikelet, X 31/3. (Courtesy of R. Godfrey). 



4. Spartina gracilis Trin. Alkali cordgrass. Fig. 127. 

Culms 3-10 dm. tall; ligules about 1 mm. long; blades flat, becoming involute, 
15-20 cm. long, very scabrous above, mostly less than 5 mm. wide; spikes 4 to 8, 
closely appressed, 2-4 cm. long; spikelets 6-8 mm. long; glumes long-ciliate on 
the keel, acute, the first 5-6 mm. long, about half as long as the second; lemma 
nearly as long as second glume, ciliate on the keel; palea as long as lemma, obtuse. 

Alkaline meadows and saline marshes and ditches, plains, in Ariz. (Apache and 
Navajo cos.); B. C. to Wash., s. to Kan., N.M. {Hitchcock) and Ariz. 

5. Spartina patens (Ait.) Muhl. Saltmeadow cordgrass. Fig. 128. 

Perennial from creeping rhizomes 2-4 mm. thick; aerial culms 25-29 cm. long, 
1-3 mm. thick, erect, unbranched; ligule about 0.5 mm. long; blades 15-40 cm. 
long, 1.5-3 mm. broad, mostly involute, the tip subspinose; panicle 9-20 cm. long, 
about 1 cm. broad; spikes 2 to 7 per panicle, 1-7 cm. long. 2-3 mm. thick, 
usually diverging at angles of 5°-45°, remote; spikelets 24 to 50 per spike, 7-12 
mm. long; first glume 3-8 mm, long; second glume 7-12 mm. long; lemma shorter 
than second glume; glumes and lemma hispid on keel, at least distally, 

Sandy seasonally moist soil near the coast, salt marshes and wet sandy mea- 
dows, in s.e. Tex. and Rio Grande Plains, common, summer-fall; shores of Great 
Lakes, Atl. and Gulf coasts, cont. N.A. and W.I.; also s. Fr., Corsica and It. 

6. Spartina pectinata Link. Prairie cordgrass. Fig. 127. 

Perennial from firm creeping rhizomes 3-8 mm. thick; aerial culms 75-200 cm. 
long, 3-10 mm. thick, erect, unbranched, leafy; ligule 1-3 mm. long; blades 2-6 
dm. long. 5-10 mm. broad at base and flat, involute toward the tip and more 
extensively involute on drying; panicle 1-3 dm. long. 2-6 cm. broad; spikes 5 to 
20 (rarely more) per panicle, 2-15 cm. long, 3-7 mm. thick, appressed or usually 
diverging at angles of 10°-20°, overlapping; spikelets 40 to 80 (rarely fewer) per 
spike; first glume 5-10 mm. long including an awnlike tip, the keel minutely 
hispid; second glume 15-25 mm. long including an awn-tip about a third to half 
the entire length, the keel pectinate with erect bristles 0.2-0.4 mm. long; lemma 
much shorter than the second glume, apically narrowed and bidentate, on the 
upper half of the dorsal keel pectinate. Incl. var. Suttiei (Farw.) Fern. 

In wet meadows, swampy ground, fresh-water or saline marshes, seepage areas, 
edge of ponds and streams, in Okla. (Ottawa and Alfalfa cos.) and n.-cen. and e. 
Tex., Plains Country and Trans-Pecos, scattered or rare, summer; s. Can., s. to 
N.C., Tenn., Ark., Tex., N.M. {Hitchcock), Ut. and Ore. 

39. Trichloris Fourn. 
A very small American genus, included by some authors in Chloris. 

1. Trichloris crinita (Lag.) Parodi. Fig. 129. 

Tufted coarse perennial; culms 4-12 dm. long; blades elongate, 2-4 mm. broad, 
pilose near the ligule; spikes digitate, 8 to 25 per panicle, 5-12 cm. long, feathery, 
nearly straight, strictly ascending; spikelets each with one fertile floret and one 
staminate or neutral; fertile lemma about 3 mm. long, both lemmas with 3 awns 
about 1 cm. long. 

Deep alluvial silty soil along or near intermittent creeks and along ditc'' 
infrequent in the Tex. Trans-Pecos and rare in w. Rio Grande Plains, N. - 
(Dona Ana Co.) and Ariz. (Graham, Pinal, Maricopa, Cochise and Pima cos. 
spring-fall; Tex. to Ariz, and s. to Dgo. and Coah.; also arid-temp, areas in 
S. A. 




Fig. 127: 1, Spartina pectinata: plant, X i/G; spikelet and floret, X 5. 2, Spartina 
gracilis: panicle, X 1; spikelet, X 5. (From Hitchcock & Chase). 




Fig. 128: Spartina patens: a, habit, X 1/3: b, ligule, X 2; c, spikelet, X 4. (Courtesy 
of R. K. Godfrey). 



40. Hierochloe R. Br. 

About 30 species in temperate and cold regions as well as tropical mountains 
in both hemispheres. 

1. Hierochloe odorata (L.) Beauv. Sweet grass. Fig. 130. 

Culms 3-6 dm. tall, with few to several leafy shoots and slender creeping 
rhizomes; blades 2-5 mm. wide, sometimes wider, those of the sterile shoots 
elongate, those of the culm mostly less than 5 cm. long, rarely to 10 cm. long; 
panicle pyramidal, 4-12 cm. long, from somewhat compact to loose with slender 
drooping branches; spikelets mostly short-pediceled, 5 mm. long; staminate lemmas 
awnless or nearly so; fertile lemma pubescent toward the apex. 

Wet meadows, bogs and moist places, in N. M. (San Miguel and Mora cos.) and 
Ariz. (Apache, Navajo, Coconino and Pima cos.); Lab. to Alas., s. to N. J., Ind., 
la., Ore., and in the mts. to N. M. and Ariz.; Euras. 

This plant, also known as holy grass, vanilla gras«^, and seneca grass, is said to 
be used by the Indians in some parts of the United States for making fragrant 
baskets. 

41. Phalaris L. Canary Grass 

Soft tufted annuals or perennials with broad flat blades and large hyaline 
scalelike ligules; inflorescences terminal dense capitate ovoid or spikelike panicles; 
spikelets sessile, 90 to 800 per panicle, strongly laterally compressed (the plane of 
the glumes perpendicular or at an angle to the axis of the panicle, in transection 
tangential to the panicle); glumes nearly equal, large, cymbiform, enclosing and 
hiding the rest of the spikelet, strongly keeled and usually with wings on the 
upper part of the keels, usually with a strong lateral nerve on each side; zone of 
abscission just above the glumes; fertile floret solitary (persistently subtended at 
the base by 2 awns or scales or glandlike structures representing the remains of 
reduced sterile florets); lemma compressed-ovoid, cartilaginous, nerveless, enclos- 
ing and falling with the palea and caryopsis (grain), usually antrorsely strigose. 

About 20 species in temperate regions. 

1. Perennial with creeping rhizomes; panicle interrupted below, the branches 
spreading in anthesis 1. P. anmdinacea. 

1. Annuals (2) 

2(1). Panicle mostly 2-6 cm. long, tapering to each end; glumes 5-6 mm. long.... 
2. P. caroUniana. 

2. Panicle mostly 2-17 cm. long, subcylindric; glumes 3.5-4 mm. long 

3. P. angiista. 

1. Phalaris anmdinacea L. Reed canary grass. Fig. 131. 

Perennial with creeping rhizomes, glaucous; culms erect, 6-15 dm. tall, gla- 
brous; panicle 5-20 cm. long, pale green or tinged with purple, narrow and dense 
or interrupted below, the branches spreading during anthesis, the lower ones as 
much as 5 cm. long; spikelets 5-6 mm. long; glumes about 5 mm. long, sharply 
keeled, narrow, acute, longer than the lemmas, the keels scabrous, wingless or very 
narrowly winged; fertile lemma lancolate, 3-4 mm. long, shining, with a few 
appressed hairs in upper part; narrow, scale-like sterile lemmas villous, 1 mm. long. 

Sloughs, marshes, wet meadows, in mud and shallow water of ponds, lakes and 
streams, in N. M. (Sandoval Co.) and Ariz. (Coconino Co.); N.B. to Alas., s. to 
N. C, Ky., N.M.. Ariz, and Calif.; Euras. 

2. Phalaris caroliniana Walt. Fig. 1 30. 

Tufted annual; culms 23-100 cm. long, 1-4 mm. thick, erect, sparingly branched 
in the lower part; ligule a hyaline scale 1-5 mm. long; blades 5-12 (-20) cm. long, 

268 




Fig. 129: A, Trichloris crinita: plant, X V2, glumes and florets, X 5. B, T. pluri flora 
(not included here.). (From Hitchcock & Chase). 




Fig. 130: 1, Hicrocliloe odorata: plant, X V.; spikelets, florets and fertile florets, 
X 5. 2, Plialaris caroliiiiana: plant, X 1; glumes and floret, X 5. (From Hitchcock & 
Chase). 



2-9 (-13) mm. broad, flat; panicle 1-6 (-9) cm. long, 8-20 mm. thick, ovoid to 
subcylindric, glumes 4.2-6.7 mm. long, narrowly winged, as viewed from the side 
3 or 4 times as long as broad; "sterile florets" subulate, 1.5-2.5 mm. long; fertile 
floret 3-4.7 mm. long; grain 2-2.3 mm. long. 

Abundant in loamy usually alluvial soils near creeks, in disturbed soils along 
roadsides and in fallow fields and pastures, in shallow water and in wet sandy 
edge of ponds and lakes, in Okla. (Waterfall), throughout Tex., common toward 
the coast, rare in the Trans-Pecos and w. Plains Country, N. M. (Grant Co.) and 
Ariz. (Graham, Gila and Yavapai to Cochise, Pima and Yuma cos.), spring; Va. 
to Okla. and s. to the Gulf States; also Ore., Calif., s. Nev., Ariz, and N.M., s. to 
Son., Chih. and Coah. 

3. Phalaris angusta Trin. 

Tufted annual; culms 55-150 cm. long, 2-6 mm. thick, erect, sparmgly branched 
in the lower part; ligule a hyaline scale 1-3 mm. long; blades 2-25 cm. long, 3-10 
mm. broad, flat; panicle 2.5-17 cm. long, 6-15 mm. broad, cylindrical; glumes 
3-5.5 mm. long, narrowly winged, as viewed from the side nearly 4 times as long 
as broad; "sterile florets" subulate, 0.7-1.5 mm. long; fertile floret 2.1-3.8 mm. 
long; grain 1.4-1.6 mm. long. 

Locally abundant in moist loamy soil near and in ditches, creeks and bayous, 
in s.e. Tex., also Ariz. (Pinal Co.), Mar.-Apr.; Ga. to Tex., w. Ariz., Calif., S. A.; 
introd. into S. Afr. 

42. Oryza L. 

About 25 species in the Old World tropics and subtropics; we have one. 

1. Oryza sativa L. Rice. Fig. 132. 

Robust annual; culms 6-20 dm. long, 4-20 mm. thick, erect, often rooting from 
lower nodes; ligule a firm lacerate scale 2-6 mm. long; blades 1-6 dm. long, 4-14 
mm. broad, flat; inflorescence an open branched drooping panicle 15-40 cm. long, 
each branch bearing a number of large spikelets; zone of abscission below each 
spikelet; spikelets sessile or usually on very short pedicels, appressed to the 
branches, slightly laterally compressed; lowermost parts of spikelets (interpreted 
either as two sterile lemmas or two glumes) small, lance-subulate, scalelike, 2-3 
mm. long; fertile floret solitary; lemma and palea fitting closely together, 7-10 
mm. long, pubescent, brownish, shining, cartilaginous-indurate, the lemma mucro- 
nate (or in some varieties awned). 

Volunteering in ditches and other muddy and seasonally flooded areas in s.e. 
Okla. (McCurtain Co.) and s.-cen. and s.e. Tex., late summer-fall; warm parts of 
the world, indigenous to Old World trop.; in Am. n. to Va. and the Gulf States. 

Economically and for the direct use of mankind this is undoubtedly the single 
most important plant species in the world. 

43. Leersia Sw. 

Perennials with few slender wiry culms; inflorescences lax open panicles with 
capillary branches; zone of abscission at the base of the spikelet; spikelets secund 
along the abaxial sides of the distal portions of the branchlets, overlapping, each 
consisting of a solitary naked fertile floret (glumes or sterile florets absent), 
laterally compressed (both lemma and palea keeled), cartilaginous, with obscure 
or conspicuous nerves. 

About 1 5 species in warmer regions of the world. 

1. Floret only 1 to 1.5 times as long as broad 1. L. lenticularis. 

1. Floret at least twice as long as broad (2) 

2(1). Spikelets 2.5-3 mm. long, closely imbricate and usually parallel with the 
branches of the panicle 4. L. virginica. 

271 





Fig. 131: Phalaris arundinacca: a, floret, showing fertile and sterile lemmas, X 8; 
b, spikelet, showing the strongly keeled glumes, fertile lemma and palea, X 8; c, panicle, 
interrupted below, X 7:,; d, leaf sheath, ligule, blade and mode, X %; e, habit, showing 
creeping rhizome, X %; f, upper part of culm, showing panicle, X %. (From Mason, 
Fig. 79). 




Fig. 132: Oryza sativa: plant, X l-z, spikelet, X 5. (From Hitchcock & Chase). 



2. Spikelets about 4 mm. long, loosely imbricate and usually pendulous and pec- 

tinately arranged at an angle to the branches of the panicle (3) 

3(2). Panicles 10-20 cm. long, open, the branches diverging 2. L. oryzoides. 

3. Panicles 5-10 cm. long, narrow, the branches ascending or appressed 

3. L. hexandra. 

1. Leersia lenticularis Michx. Catchfly grass. Fig. 133. 

Perennial with short scaly rhizomes (these seldom present on prepared speci- 
mens); aerial culms 7-15 dm. long, 1-3 mm. thick, erect or often sprawling and 
distally ascending; ligule a tough scale about 0.5 mm. long; blades 13-40 cm, long, 
1-2 cm. broad, flat; panicle 1-2 dm. long, very open and subpyramidal, often 
nodding, the branches naked about half their length; florets 4-5 mm. long, nearly 
or quite as broad as long, sparsely pubescent, the keels comb-toothed. 

Sloughs, bayous, ditches, swamps and in mud and shallow water, and marshy 
prairies in Okla. (Waterfall) and e. and s.e. Tex., infrequent or locally abundant, 
late summer-fall; Md. to Minn., s. to the Gulf States. 

2. Leersia oryzoides (L.) Sw. Rice cutgrass. Fig. 134. 

Perennial with short slender scaly rhizomes; culms 7-15 dm. long, 2-3 mm. 
thick, often decumbent and rooting at the lower nodes or erect, shortly bearded 
at the nodes; ligule a firm scale about 0.5 mm. long; blades (3-) 7-25 cm. long, 
6-11 mm. broad, flat; panicle 1-2 dm. long, open, the branches diverging, naked 
for less than half their length; florets 3.7-5.5 mm. long, about 2.5 times as long 
as broad, pubescent, the keels comb-toothed. 

Near and along creeks, in marshes, swamps, muddy borders of ponds, ditches 
and rivers, often forming dense zones, in Okla. (McCurtain, Ottawa and Stephens 
COS.) and in e. and n.-cen. Tex.. Edwards Plateau, n.w. part of Rio Grande Plains 
and Plains Country, and Ariz. (Navajo Co.). infrequent, mostly spring-fall; most 
of U. S. n. to Que. and B. C. (not known from Mont., Wyo., Nev. or Mex.) 

The seeds and rootstocks of this species are a favorite food of various ducks, 
marsh birds and shore birds. 

3. Leersia hexandira Sw. Fig. 135. 

Perennial with short slender scaly rhizomes; culms 5-10 dm. long, 1.5-3 mm. 
thick, usually long-decumbent and rooting at the lower nodes, shordy bearded at 
the nodes; ligule a firm scale about 0.5 mm. long; blades 5-18 cm. long, 3-7 (-10) 
mm. broad, flat; panicle 5-9 (-12) cm. long, 1-2 cm. broad, the few branches 
acending or appressed, naked for less than half their length; florets 3.3-4.5 mm. 
long, about 2.5 times as long as broad, sparsely pubescent, the keels minutely 
comb-toothed. 

Near creeks, in shallow water of ditches and wet places, and in rivers and 
resacas in e. and s.e. Tex. and coastal parts of the Rio Grande Plains, infrequent, 
spring-fall; widely distributed in warmer parts of the world, in Am. n. to. Va. and 
the Gulf States. 

4. Leersia virginica Willd. White grass. Fig. 135. 

Perennial with short rhizomes 2-4 mm. thick (these seldom present on pre- 
pared specimens); culms 25-120 cm. long, 1-1.5 mm. thick, often geniculate and 
rooting at a few of the lower nodes but mostly ascending or erect, upper nodes 
minutely bearded; ligule a scale about 1 mm. long; blades 4-10 (-13) cm. long, 
3-8 mm. broad, flat; panicle 5-10 (-18) cm. long, the very few branches diverg- 
ing, naked for more than half their length; florets 2.5-3 mm. long closely ap- 
pressed and parallel to the branches, 2 to 3 times as long as broad, microscopically 
pubescent on sides and keels. 

274 




Fig. 133: Leersia lenticularis: a, basal part of plant, X \(i, b, top of plant, X \(i; c, 
branch of panicle, X 1. (Courtesy of R. K. Godfrey). 




Fig. 134: Leersia oryzoides: a, panicle, X %; b, seed. X 8; c, habit, showing the 
slender creeping rhizomes and the culms with decumbent bases, X Vs; d, spikelet, 
laterally compressed, the glumes wanting, X 8. (From Mason, Fig. 71). 



Swamps and bogs along bayous, rivers and streams, and sand flats on the edge 
of ponds and lakes, in Okla. (Creek Co.) and in e., s.e. and n.-cen. Tex., infrequent 
to rare, spring-fall; e. U.S. w. to S.D., Neb., Kan., Okla. and Tex. 

44. Zizania L. Wild-rice 

Tall aquatic annuals or perennials with flat blades; panicles large, terminal, the 
lower branches ascending or spreading and bearing the pendulous early deciduous 
staminate spikelets, the upper branches ascending (at maturity erect) and bearing 
the appressed tardily deciduous pistillate spikelets; spikelets 1 -flowered, disarticulat- 
ing from the pedicel; glumes obsolete, represented by a small collarlike ridge; 
staminate spikelet soft; lemma 5-nerved, membranaceous, linear, acuminate or 
awn-pointed; palea about as long as the lemma, 3-nerved; stamens 6; pistillate 
spikelet terete, angled at maturity; lemma chartaceous, 3-nerved, tapering into a 
long slender awn; palea 2-nerved, closely clasped by the lemma; grain cylindric, 
1-2 cm. long. 

A genus of 2 species in North America and one in Asia. 

1. Perennial, long-decumbent at base, growing in rapidly flowing water 

1. Z. texana. 

1. Annual, erect, growing usually in shallow still water 2. Z. aquatica. 

1. Zizania texana Hitchc. Texas wild-rice. Fig. 135. 

Coarse perennial; culms long-decumbent and rooting at nodes stoloniform, 
distally ascending, 1-3 m. long, 3-13 mm. thick; ligule a scale 5-15 mm. long; 
blades 12-110 cm. long, 5-23 mm. broad, flat, forming long streamers beneath 
surface of water; panicle 2-3 dm. long, the lower portion with spreading branches 
bearing staminate spikelets, the upper part with ascending or appressed branches 
bearing pistillate spikelets; zone of abscission below the floret or spikelet; spikelets 
consisting of a single naked floret (glumes obsolete or absent); staminate spikelets 
pendulous, 7-9 mm. long, 1.5 mm. broad, not indurated nor awned; pistillate 
spikelets erect, about 10 mm. long and 1 mm. broad, terete or at least not laterally 
compressed, the lemma indurate at maturity and bearing an awn 10-23 mm. long. 

In clear cool fast-flowing spring-water in the San Marcos River, Hays Co., Tex., 
where it is becoming rare, fall-spring, usually early spring; endemic. 

2. Zizania aquatica L. Northern wild-rice. Fig. 136. 

Tall annual; culms robust, to 1.5 m. long, often long-decumbent at base and 
rooting at the nodes, spongy, but usually thickened at the nodes; sheaths glabrous, 
somewhat inflated above; blades flat 5-12 (to 50) mm. wide, densely pubescent 
at the base on both surfaces and on the nodes, otherwise minutely scabrous; ligules 
5-10 mm. long, ovate, hyaline, acute or somewhat lacerate at the summit; panicles 
large, 3-5 dm. long, terminal, monoecious, the lower branches ascending or 
spreading, bearing 1 to 15 pendulous reddish staminate spikelets on short capillary 
pedicels, the upper branches ascending, at maturity erect, bearing 2 to 6 appressed 
pistillate spikelets on short club-shaped pedicels; the staminate spikelets early- 
deciduous and the pistillate spikelets tardily deciduous; spikelets 1 -flowered, dis- 
articulating from the pedicel; glumes obsolete, represented by a small collarlike 
ridge; pistillate spikelet terete, angled at maturity, 4.5-8 cm. long, bearing a long 
bristlelike awn 2.5-6 cm. long (the body of the spikelet 2-3 cm. long); pistillate 
lemma rather firm and tough to thin and papery, strawlike with a somewhat 
lustrous glabrous surface, appressed-scabrous over the entire surface or on the 
margins, at the base and summit, along the awn and sometimes on the 3 nerves, 
the lemma closely clasping the palea by a pair of strong lateral nerves; aborted 
spikelets are very slender and shriveled, without a definite body; caryopsis nar- 
rowly cylindrical, about 1.5 cm. long, pale brown to dark brown. 

277 




Fig. 135: 1, Zizania texana: plant, X V.; pistillate and staminate spikelets, X 5. 2, 
Leersia hexandra: X 1. 3, Leersia virginica: X 1. (From Hitchcock & Chase). 




S^>--. 



Fig. 136: Zizania aquatica: a, top of plant, X %; b, staminate spikelet, X 4; c, 
pistillate spikelet, X 4. (Courtesy of R. K. Godfrey). 



In water and mud of springs, marshes, lakes and ponds, in Ariz. (Coconino Co., 
s. of Flagstaff), June-Sept.; in most of s. Can. and e. U.S., w. to Minn., Ariz, 
and Mo. 

Several varieties are recognized. Our plant is referred to var. augustifoUa Hitchc, 
characterized by having leaves 4—15 mm. wide, ligules 3-10 mm. long, and lower 
pistillate branches with 2 to 6 spikelets. 

This provides the "wild rice" of commerce, and it is still harvested to some 
extent in the Great Lakes region. The seeds are a favorite food of ducks, rails, 
blackbirds, bobolinks and other birdlife, and it is especially valuable in northern 
United States and Canada where it thrives in mud and water of quiet lakes 
and ponds. 

45. Zizaniopsis Doell & Asch. 

A genus of 4 species in North America and South America; we have one 
species. 

1. Zizaniopsis miliacea (Michx. ) Doell & Asch. Southern wild-rice. Fig. 137. 

Coarse perennial from creeping rhizomes, 5-11 mm. thick; culms 9-30 dm. 
long, 5-15 mm. thick, rooting at some of the lower nodes, mostly erect and 
unbranched; ligule a scale 5-15 mm. long; blades 15-100 cm. long, 8-22 mm. 
broad, flat; panicle 3-6 dm. long, 10-17 cm. broad, the main branches verticillate 
and ascending, much verticillately rebranched with each branchlet bearing some 
pistillate spikelets and some staminate ones, both kinds ascending and appressed 
and superficially similar; zone of abscission below the floret; each spikelet consist- 
ing of a single naked floret (glumes obsolete or absent), 6-8 mm. long, ellipsoidal, 
acuminate, not at all laterally compressed; lemma 7-nerved, mucronate or with 
an awn 2-3 mm. long. 

At the edges of streams, in marshes, along sloughs and in shallow water of 
ponds and lakes, in Okla. (McCurtain and Pushmataha cos.) and s.e., e. and 
n.-cen. Tex., Edwards Plateau and extreme n. Rio Grande Plains, locally abundant, 
spring-fall; Coastal States, Md. to Tex., n. to Ky., Ark. and Okla. 

46. Hydrochloa Beauv. 
A monotypic genus of southern United States. 

1. Hydrochloa caroliniensis Beauv. Fig. 138. 

Mostly submerged bottom-rooted aquatic perennial; culms 3-10 dm. long, about 
0.5 mm. thick, often rooted at most nodes, somewhat branched; ligule a scale of 
0.5-1 mm. long; blades floating near surface or usually emergent a few cm., 
2-4 (-6) cm. long, 2-3 (-5) mm. broad; panicles 5-20 mm. long, racemiform, 
few-flowered, the terminal ones with staminate spikelets, the subterminal axillary 
ones with pistillate spikelets; zone of abscission below the floret; each spikelet 
consisting of a single naked floret (glumes obsolete or absent), not indurated and 
scarcely compressed; staminate floret about 4 mm. long, pistillate ones about 2 
mm. long. 

Ponds, lakes and slow-flowing streams in e. Tex., rare, late summer; Coastal 
States, N. C. to Tex. 

This is a very inconspicuous grass and may well be more common than is indi- 
cated by the few collections. It sometimes becomes so thick where it grows as to 
become a nuisance. 

47. Anthaenantia Beauv. 

Erect perennials with short creeping rhizomes; blades narrow, firm, flat, the 
uppermost much-reduced; panicles terminal, narrow, the slender branches ascend- 
ing or appressed; spikelets obovoid, 2-flowered, the lower flower reduced; first 

280 




Fig. 137: Zizaniopsis miliacea: a, habit, about X i^; b, branch, X 1; c, young 
staminate spikelets, X 5; 6, staminate spikelet, X 5; e, pistillate spikelet, X 5. (V. F.). 




Fig. 138: Hydrochloa caroliniensis: a, habit, X V2', b, young staminate spikelet, 
X 5; c, staminate spikelet, X 5; d, young pistillate spikelet, X 10; e, mature pistillate 
spikelet, X 10; f, caryopsis, X 18. (Courtesy of R. K. Godfrey). 



glume absent; second glume and sterile lemma about equal, 5-nerved, the broad 
intemerves infolded, densely villous; sterile lemma with a small palea and some- 
times with a staminate flower; fertile lemma cartilaginous, brown, with narrow 
pale hyaline margins, cymbiform, 3-nerved, subacute. 
An American genus of 2 species. 

1. Blades erect or spreading, rather blunt or rounded at apex, linear, folded at 
base; panicle usually purple 1. A. rufa. 

1. Blades ascending or spreading (on the average shorter and broader than in 
A. rufa), tapering to apex, rounded at base; panicle usually pale.... 
2. A. villosa. 

1. Anthaenantia rufa (Ell.) Schult. Fig. 139. 

Culms slender, 6-12 dm. tall; blades elongate, 3-5 mm. broad, often scabrous; 
panicle 8-15 cm. long, usually purple; spikelets 3-4 mm. long. 

Infrequent in wet savannahs and sandy woodlands, e. and s.e. Tex., summer- 
fall; Coastal States, N. C. to Tex. 

2. Anthaenantia vUIosa (Michx.) Beauv. Fig. 139. 

Differing from A. rufa in the broader, mostly shorter, spreading blades and in 
the usually pale panicles. 

Rare in sandy woodlands and wet savannahs, in mud on edge of ponds, s.e. 
and e. Tex., summer-fall; Coastal States, N.C. to Tex. 

48. Digitaria Fabr. Crabgrass 

A genus of several hundred species in warm regions, sometimes made to include 
the related genera Trichachne and Leptoloma. The introduced annual crabgrasses, 
D. sanguinalis, and the more abundant native D. adscendens and D. diversiflora 
are persistent and pernicious weeds in the loamy soil of plowed fields, lawns and 
flowerbeds. 

1. Digitaria sanguinalis (L.) Scop. Northern crabgrass. Fig. 140. 

Tufted and/ or usually stoloniferous annual freely rooting at the nodes; culms 
15-90 cm. long, 1-3 mm. thick, usually long-decumbent, ascending only at the 
ends; ligule a thin scale 1-2 mm. long; blades 2-7 cm. long, 3-10 mm. broad, 
flat, usually crisped, sparsely or usually densely papillose-pilose; sheaths papillose- 
pilose; panicle axis 1-15 (-30) mm. long; racemes 2 to 11, 4-12 cm. long, 1-2 
mm. thick, often purplish, the wing of the rachis as broad as the central rib; spike- 
let 2.3-3.2 mm. long; first glume present but minute; second glume 1-1.9 mm. 
long, narrow, a third to three fifths (usually half) as long as the spikelet; sterile 
lemma as long as the spikelet, usually with a sparse short antrorse-appressed silky 
fringe on the margins and the 2 to 4 lateral nerves usually with minute inflexible 
pointed cilia (as seen under a powerful lens); "fruit" (the lemmas and its 
enclosures) often pale-plumbeous. 

Disturbed soil along roads, in fields and gardens, along irrigation ditches, 
margin of ponds and spring branches and wet gravel bars, in Okla. (LeFlore, 
Ottawa and Mayes cos.), frequent in the Tex. Plains country and infrequent to 
Trans-Pecos, n.-cen. and e. Tex., s. as far as Travis and Gonzales cos., summer- 
fall; s. Can., N. E., s. to Va., w. and s.w. to Wash., Calif, and Tex.; scattered in 
U. S.; also Son., Chih. and Dgo.; introd. from n. Eur., now widespread in temp, 
areas. 

49. Eriochloa H. B. K. Cupgrass 

Tufted annuals or perennials; inflorescence an elongate panicle of racemes 
attached in 2 rows along 1 side of a more or less flattened axis (or on 2 sides 
when the axis is vaguely broadly triangular in transection); racemes with more 

283 





.v;s;y 










Fig. 139: 1, Anthaemmtia villosa: plant, X 1^2; spikelet and floret, X 10. 2, An- 
thaenaiuhia rufa: spike, X 1. (From Hitchcock & Chase). 



or less flattened (or in transection broadly triangular) rachises; zone of abscission 
at the base of the spikelet below the callus; spikelets attached in 2 rows abaxially 
on the rachis, strongly dorsally compressed, each with one perfect floret, solitary 
or paired or at the bases of the raceme in racemelets of 3 (in extralimital species 
the basal racemelets have up to 15 spikelets in 2 rows along the abaxial side of 
a flattened rachilla, the "raceme" then being a small panicle), commonly the 
uppermost spikelets solitary even when the lower ones are paired and the 
pedicelled one slightly larger than the sterile one of the same pair; first glume 
truncate, about 0.1 mm. long, discolored, closely investing the minute swollen 
portion of the rachilla below the second glume, the swelling and the glume con- 
stituting the "callus"; second glume as large as the spikelet, abaxial, marginally 
often revolute; sterile lemma toward the rachis, nearly as large as the second 
glume; fertile lemma abaxial, thin-cartilaginous but not indurate, stramineous, 
elliptic-oblong, shorter than the second glume, marginally revolute and clasping 
the palea of the same texture, surficially with microscopic transverse rugae or 
puncticulate and apically mucronate or with an antrorsely scabrous awn. 

About 20 species in warm regions. The spikelet measurements given below do 
not include the "callus". 

1. Plant perennial (but flowering the first year); foliage essentially glabrous; 
spikelets slightly acuminate or usually merely tapered to a point, 
usually with a purplish tinge; fertile lemma with an awn 0.9-1.5 
mm. long 1. E. punctata. 

1. Plant annual; foliage finely pubescent (as seen under a lens), rarely glabrate; 
spikelets distinctly acuminate to a very fine point, usually greenish; 
fertile lemma with an awn 0.3-0.8 (-1) mm. long.. ..2. E. contracta. 

1. Eriochloa punctata (L.) Desv. Fig. 140. 

Tufted weak perennial but flowering the first year: culms 3-10 dm. long, 
2-5 mm. thick, commonly geniculate and stoloniform basally, distally ascending, 
leafy; ligule a fringe about 1 mm. long; blades (3-) 10-27 cm. long, 3-10 mm. 
broad, mostly flat or folded, essentially glabrous; panicle dense and elongate 
with numerous broadly overlapping ascending racemes; pedicels merely scabrous, 
without any longer hairs; spikelets solitary or paired or in threes, 4-6 mm. long, 
tapered to the slightly or not acuminate apex, purplish when mature; fertile lemma 
with an awn 0.9-1.5 mm. long. 

Tight loamy moist soil near ponds or seasonally muddy areas, in marshes 
and on river banks in s.e. Tex. and coastal parts of the Rio Grande Plains, 
frequent, spring-fall; warmer parts of Am., n. to La. and Tex. 

Some plants seem intermediate between this species and E. contracta. 

2. Eriochloa contracta Hitchc. Prairie cupgrass. Fig. 140. 

Tufted annual; culms 2-8 dm. long, 1-4 mm. thick, geniculate and infrequently 
shortly stoloniform basally, mostly ascending, leafy; ligule a fringe 1-2 mm. long; 
blades 3-20 cm. long, 2-6 mm. broad, mostly flat or folded, or eventually 
involute, shortly pubescent (like the sheaths); panicle narrow, with overlapping 
erect racemes; pedicels scabrous and also apically with some long erect cilia 
a third to half as long as the spikelet; spikelets solitary or paired, (3.1-) 3.7-4 
(-5) mm. long, somewhat shaggy-pubescent, acuminate to a long fine point, 
greenish to stramineous at maturity; fertile lemma with an awn 0.3-0.8 (-1) mm. 
long. 

Tight loamy usually seasonally moist soil near swales in prairies and at edges 
of fields and roadsides and lawns, in ditches, marshy areas and wet depressions, 
in Okla. (Nowata Co.) and s.e. Tex. and Rio Grande Plains n. to. n.-cen. Tex., 
infrequent w. to e. Plains Country, and Ariz. (Santa Cruz, Pima and Yuma cos), 
spring-fall; Neb. s. to Tex. and La., w. to Colo, and Ariz.; adv. in Mo. and Va, 

285 




Fig. 140: 1, Difjitaria sanf^iiinalis: plant. X '^■y, two views of spikelets and floret, 
X 10. 2, Eriochloo punctata: panicle, X 1; floret, X 10. 3, Eriochloa contractu: panicle, 
X 1; floret, X 10. (From Hitchcock & Chase). 



50. Axonopus Beauv. 

Tufted and usually stoloniferous perennials; blades broad and flat; floriferous 
culm at anthesis short, after anthesis greatly elongating, filiform; panicle a 
terminal pair of ascending divergent linear spikes, with or without another 1 or 2 
spikes attached to the axis subterminally; spikes with flattened or even narrowly 
winged rachises; zone of abscission at the base of the spikelet; spikelets solitary, 
in 2 rows on the abaxial side of (and appressed to) the rachis, considerably 
dorsally compressed; first glume absent; "second" (or only) glume abaxial (away 
from the rachis), as large as the spikelet; sterile lemma appressed to the rachis 
(sterile palea absent); fertile lemma oblong, abaxial, thin-cartilaginous but not 
indurate, the margins revolute and clasping the palea of the same texture; fertile 
floret perfect. 

A genus of warm parts of America, with perhaps as many as 75 species. They 
are of considerable importance in pastures near the coast in east and southeast 
Texas. 

1. Spikelets 4.5-6 mm. long; spikes about 2 mm. thick 1. A. furcatus. 

1. Spikelets 1.7-3 mm. long; spikes about 1 mm. thick (2) 

2(1). Spikelets (2.3-) 2.5-3 mm. long 2. A. compressus. 

2. Spikelets 1.7-2.2 mm. long 3. A. affinis. 

1. Axonopus furcatus (Fliigge) Hitchc. Fig. 141. 

Stoloniferous perennial with floriferous tufts at the nodes; culms 4-10 dm. 
long, compressed, 2-4 mm. wide on the broad axis; ligule a minute firm scale or 
obsolete; blades 5-15 (-25) cm. long, 5-10 (-13) mm. broad, blunt; spikes 2, 
digitate, 4-10 cm. long, about 2 mm. thick; spikelets 4.5-6 mm. long, glabrous, 
apically pointed. 

Moist sand, in marshes, on river banks and wet pine barrens, e. and s.e. Tex., 
infrequent, summer-fall; Coastal States. Va. to Tex.; also Ark. 

2. Axonopus compressus (Sw.) Beauv. Fig. 141. 

Tufted perennial; culms 20-75 cm. long, compressed, about 2 mm. broad on 
the long axis, often rather long-stoloniferous basally, the tufted floriferous culms 
erect and unbranched; ligule a scale about 0.5 mm. long; blades 8-25 cm. long 
(shorter on stolons), 5-7 (-10) mm. broad; spikes 2 to 4, 4-10 cm. long, 1 mm. 
thick; spikelets (2.3-) 2.5-3 mm. long, minutely pubescent basally, apically 
pointed, the point prolonged beyond the blunt end of the fruit. 

Moist or wet sand, s.e. Tex., rare (near Anahuac, Chambers Co.), mostly in 
the fall; widespread in warmer parts of Am., n. to Fla., La. and Tex. 

3. Axonopus affinis Chase. Carpet grass. Fig. 141. 

Tufted perennial; culms 20-75 cm. long, compressed, about 2 mm. broad on the 
long axis, often rather long-stoloniferous basally, forming carpets but the tufted 
floriferous culms erect and unbranched; ligule a scale about 0.3 mm. long; blades 
6-17 (-28) cm. long, shorter on the stolons, 3-6 (-9) mm. broad, flat, blunt; 
sheaths keeled, spikes 2 to 4, 2-10 cm. long, about 1 mm. broad; spikelets 1.7-2.2 
mm. long, very minutely pubescent around the edges, apically rather blunt, the 
"second" glume not much if any prolonged beyond the fruit. 

Moist sand, in wet mucky or sandy meadows, openings in forests, roadsides, 
in s.e. Okla. {Waterfall) and e. and s.e. Tex., very frequent, spring-fall (in 
Calhoun, Jackson and Aransas cos. even as late as Dec. and as early as Feb.); 
widespread in warmer parts of Am. n. to N. C. and the Gulf States, Ark. and 
Okla. 

287 




Fig. 141: 1, Axonopus compressiis: plant, X i/>; two views of spikelet and floret, 
X 10. 2, Axonopus f meatus: plant, X 1; spikelet and floret, X 10. 3, Axonopus affinis: 
two views of spikelet and floret, X 10. (From Hitchcock & Chase). 



51. Paspalum L. Paspalum 

Mostly perennials; ligule a scale; inflorescence a panicle of 1 to several racemes 
on the common axis; raceme with a more or less flattened rachis; the numerous 
spikelets borne in pairs or singly in 2 rows on the abaxial side of the rachis, the 
pedicels of the pairs short and unequal in length; zone of abscission at the base of 
the spikelet at the end of the pedicel; spikelets each with a single perfect floret 
subtended by 2 or 3 scales, when 3 then the lowest one being a minute abaxial 
first glume; next highest one of the adaxial second glume as large or nearly as 
large as the spikelet; the abaxial sterile lemma representing the sole remains of a 
neutral lower floret; fertile lemma adaxial, chartaceous-indurate, convex, the 
margins revolute, clasping the fertile palea of similar texture, the fertile lemma 
and palea and their enclosures and appendages constituting the "fruit." 

A genus of about 250 species in warm regions. Most Paspalums are of great 
economic importance as forage plants. 

I. Racemes 20 to 50 per panicle, eventually deciduous from the panicle axis; 

commonly attached and floating aquatics; spikelets solitary, 1.2-1.7 
mm. long, pubescent 16. P. fluitans. 

1. Racemes fewer, persistent (2) 

2(1). "Second" (only) glume and sterile lemma abruptly pointed beyond the 
blunt fruit (3) 

2. Second (only) glume and sterile lemma not abruptly pointed beyond the 

fruit (5) 

3(2). Spikelets solitary (that is, not paired) and glabrous; fruit with microscopic 
cilia apically 14. P. acuminatum. 

3. Spikelets paired and silky-fringed (4) 

4(3). Racemes (8 to) 12 to 22 per panicle; spikelets 2-3 mm. long 

5. P. Urvillei. 

4. Racemes 3 to 6 (to 11) per panicle; spikelets 2.8-4.1 mm. long 

6. P. dilatatum. 

5(2). Spikelets 3.6-5 mm. long (6) 

5. Spikelets less than 3.6 mm long (8) 

6(5). Spikelets solitary 13. P. vaginatum. 

6. Spikelets paired; fruit brown (7) 

7(6). Spikelet pairs remote, usually not overlapping; first glume present on at 

least some of the spikelets; rachis of raceme 0.5-0.8 mm. broad 

1. P. bifidum. 

7. Spikelet pairs approximate, overlapping; first glume absent; rachis 1-1.5 mm. 

broad 2. P. floridanum. 

8(5) . All the spikelets solitary, never paired (9) 

8. Some and usually nearly aU the spikelets paired (12) 

9(8). Spikelets 1.4-2.3 mm. long 15. P. dissectum. 

9. Spikelets 2.4-3.6 mm. long (10) 

10(9). Panicle axis 3-10 (-19) cm. long; racemes 2 to 9 per panicle 

7. P. laeve. 

10. Panicle axis obsolete or only to 2.5 cm. long; racemes 1 to 3 per panicle (11) 

11(10). Spikelets 2.5-3.2 mm. long; second glume minutely pubescent; first 
glume usually present 12. P. distichum. 

II. Spikelets 3.1-4.5 mm. long; second glume nearly glabrous; first glume usually 

absent 13. P. vaginatum. 

289 



12(8). Fruits (fertile lemmas) brown or brownish-olive at maturity (13) 

12. Fruits (fertile lemmas) whitish or stramineous at maturity (14) 

13(12). Panicle axis 12-25 cm. long; racemes 7 to 25 per panicle; spikelets con- 
spicuously pubescent; fruits pale-brown 4. P. virgatum. 

13. Panicle axis to 13 cm. long; racemes 1 to 15 per panicle; spikelets essentially 

glabrous or minutely pubescent; fruits quite brown. .3. P. Bosciamim. 

14(12). Spikelets orbicular or suborbicular, glabrous 8. P. praecox. 

14. Spikelets longer than broad (15) 

15(14). Spikelets thickly turgidly plano-convex, usually pubescent: rachis rarely 

with purplish coloration; racemes only 1 to 6 per panicle 

1 1. P. pubiflorum. 

15. Spikelets flatly compressed plano-convex; rachis usually with a distinct pur- 

plish color; racemes usually more numerous, 3 to 15 per panicle 
(16) 

16(15). Spikelets (2.1-) 2.3-2.7 (-2.9) mm. long, glabrous 9. P. lividum. 

16. Spikelets (2.2-) 2.5-2.9 (-3.2) mm. long, pubescent 10. P. Hartwegianum. 

1. Paspalum bifidum (Bert.) Nash. Fig. 142. 

Perennial from rhizomes 3-4 mm. thick with pubescent scales; aerial culms 
5-12 dm. long, 2-3 mm. thick, erect, unbranched; ligule a thin brownish scale 
1-5 mm. long; blades 1-5 dm. long, 3-14 mm broad, flat or folded, densely 
pilose at least near the ligule and often on both surfaces; sheaths pilose; panicle 
axis 12-20 cm. long; racemes 2 to 6, 4-16 cm. long, ascending or somewhat 
spreading; rachis 0.5-0.8 mm. broad, triangular in transection, often markedly 
zigzag; spikelets paired or by abortion a few solitary in the same raceme (the pairs 
remote from each other and not much if at all overlapping), 3.6-4.2 mm. long, 
ovate to obovate, brownish, turgidly plano-convex, glabrous; first glume present 
as a minute triangle at the base of the sterile lemma; second glume and sterile 
lemma firm-membranous; fruit brownish-green or olivaceous. Incl. var. projectum 
Fern. 

In moist acid sand near bogs and open woods, in mud and shallow water of 
bayous, sloughs, streams and ponds, in Okla. {Waterfall), infrequent or rare in 
e. Tex., Sept.-Oct.; Coastai States, from Va. to Tex. and inland to Ark. and Okla. 

2. Paspalum floridanum Michx. Fig. 142. 

Robust perennial from short rhizomes 3-6 mm. thick with pubescent scales; 
aerial culms (5-) 8-15 (-20) dm. long, 2-5 mm. thick, erect, unbranched; ligule 
a brownish scale 1-2 mm. long; blades 1-5 dm. long, 4-13 mm. broad, firm, flat 
or folded, glabrous to pilose; sheaths keeled, glabrous to pilose; panicle axis (when 
racemes not solitary) 4-13 (-20) cm. long; racemes (1 or) 2 to 4 (to 6), 4-15 cm. 
long, ascending or somewhat spreading; rachis 1-1.5 mm. broad, usually strongly 
zigzag, the central rib to which the pedicels are attached even more markedly 
zigzag, the very narrow margins thus interrupted; spikelets paired or by abortion 
some solitary on the same raceme, 3.6-5 mm. long, ovate to obovate, usually 
broadly so, brownish, turgidly plano-convex, glabrous; first glume always absent 
or present as a mere minute line at the base of the sterile lemma; second glume 
and sterile lemma firm-membranous, sometimes the latter slightly wrinkled; fruit 
pale-brownish. Incl. var. glabratum Engelm. 

Permanently or seasonally moist clay or sandy loam, seepage areas, flatwoods, 
in and about lakes and marshes, in shallow water in depressions in savannahs, and 
in cat-tail ponds, in Okla. (Pittsburg. Ottawa, Love, Osage, Le Flore and Mayes 
COS.) and e., s.e. and n.-cen. Tex. and extreme n.e. Rio Grande Plains, frequent, 
summer-fall; N. J. to 111., Mo. and Kan., s. to the Gulf States. 

290 





1 




Fig. 142: 1, Paspahim Boscianum: panicle, X 1; two views of spikelet and floret, 
X 10. 2, Paspalum bifidum: panicle, X 1; two views of spikelet and floret, X 10. 3, 
Paspalum floridanum: panicle, X 1; two views of spikelet, and floret, X 10. (From 
Hitchcock & Chase). 



3 Paspalum Boscianum Fliigge. Bull paspalum. Fig. 142. 

Tufted annual; culms 3-10 dm. long, 2-7 mm. thick, ascending, often prostrate 
basally, rooting and genuflexed at the nodes, purple; ligule a brown scale 2-4 mm. 
long; blades 1-4 dm. long, 5-13 mm. broad, flat or folded, pilose near the ligule; 
lowermost sheaths inconspicuously pilose; axis of panicle 5-10 cm. long; racemes 
(2 to) 4 to 11 (to 15), 2-9 cm. long, ascending, arcuate, pilose in the axils; rachis 
2-2.5 mm. broad, olivaceous, the pedicels attached in a narrow central rib, the 
marginal winglike portions mostly broader than the rib; spikelets paired or by 
abortion a few in the same raceme solitary, 2-2.3 mm. long, plano-convex, 
brownish, obovate-orbicular, glabrous; first glume always absent; second glume 
and sterile lemma thin; fruit brown and shining at maturity. 

In moist or wet open ground, along margins of ditches and ponds, reported to 
occur in e. Tex., summer-fall; Coastal States, Va. to Tex. and inland to Tenn. 
and Ark.; W. I. 

4. Paspalum virgatum L. Fig. 143. 

Robust tufted perennial; culms 1-2 m. long, 2-8 mm. thick erect, unbranched; 
ligule a scale 0.5-2.5 mm. long; blades 30-75 cm. long, 10-25 mm. broad, firm, 
flat, marginally serrulate, pilose near the ligule; sheaths pilose at the summit; axis 
of panicle 12-25 cm. long; racemes 7 to 25, 3-15 cm. long, ascending; rachis 
1-1.5 mm. broad, purplish-olive or olive-purple, the central rib (to which the 
pedicels are attached) narrow, the winglike margins slightly broader than the rib, 
commonly with some few scattered cilia; spikelets paired, 2.5-3.2 mm. long, 
brownish or purplish-brown, elliptic to narrowly obovate, much-compressed, 
plano-convex; first glume always absent; second glume softly spreading pubes- 
cent, the hairs longer near the margin; sterile lemma often nearly glabrous; fruit 
pale-brownish. 

Moist clay loam, disturbed places, in wet or swampy ground, in the Tex. s. Rio 
Grande Plains, rare (Cameron Co.); widespread in trop. Am. n. to Tex. and Cuba. 

5. Paspalum UrvUIei Steud. Vasey grass. Fig. 144. 

Tufted perennial, often shortly subrhizomatous basally; culms 7-20 dm. long, 
2.5-8 mm. thick, mostly strictly erect; ligule a scale 3-6 mm. long (base of blade 
pilose); blades 1-4 dm. long, 4-13 mm. broad, flat, essentially glabrous except 
near the ligule; lowerrriost sheaths densely pilose; panicle axis 8-25 cm. long; 
racemes (8 to) 12 to 22, 2-13 cm. long, pilose at the axils; rachis about 1 mm. 
broad, greenish and purplish, flattened, the pedicels attached at the central rib, 
the marginal portions about as broad as the rib; spikelets paired, (2-) 2.2-2.7 (-3) 
mm. long, broadly obovate, greenish-stramineous, much-flattened, plano-convex, 
extended in the broad triangular point beyond the fruit; first glume always absent; 
second glume softly silky-pubescent, this pubescence much longer near the margins 
than in the center; sterile lemma nearly glabrous at the center; fruit elliptic-oblong, 
slightly obovate. 

Loamy disturbed usually very moist soil, in wet savannahs, in ponds and along 
ditches and streams, in s.e. Okla. (Waterfall), e., s.c. and n.-cen. Tex., rare w. to 
Edwards Plateau, spring-fall; nat. of S. A., now distributed in N. A., n. to N. C, 
the Gulf States and Ark.; Calif. 

6. Paspalum dilatatum Poir. Dallis grass. Fig. 145. 

Tufted perennial, shortly subrhizomatous basally; culms 3-15 dm. long, 2-6 
mm thick, erect or somewhat sprawling and slightly genuflexed and rarely rooting 
at the lower 1 or 2 nodes; ligule a scale 2-5 mm. long (base of blade pilose); 
blades 7-36 cm. long, 4-12 mm. broad, flat, essentially glabrous except near the 
ligule; lowermost sheaths pilose; panicle axis (3-) 5-10 (-15) cm. long; racemes 
3 to 6 (to 11), 4-12 cm. long, pilose at ihe axils; rachis 0.8-1.7 mm. broad, 

292 





1 




Fig. 143: 1, Paspahim virgatum: panicle, X 1; two views of spikelet and floret, 
X 10. 2, Paspalum praecox: panicle, X 1; two views of spikelet and floret, X 10. 3, 
Paspahtm lividum: panicle, X 1; two views of spikelet and floret, X 10. (From Hitch- 
cock & Chase). 




(Pfi Hlfchco^kTchLse")""""" ""'"'• "" ■-' '"° "'"'' °' '"""'« ="" "<•-'■ '^ '»■ 



greenish or purplish-olive, flattened, the pedicels attached at the narrow central 
rib, the marginal portions winglike and at least as broad as the rib; spikelets 
paired, (2.8-) 3.2-3.5 (-4.1) mm. long, basally obovate, greenish-stramineous, very 
flattened, compressed plano-convex, extended in a broad triangular point beyond 
the fruit; first glume always absent; second glume softly pubescent, shortly so in 
the middle but near the margins with a long silky fringe; sterile lemma softly 
pubescent; fruit nearly orbicular. 

Loamy disturbed soils in marshy meadows, along streams and irrigation ditches, 
in mud and water of marshes, lakes and ponds, in Okla. (McCurtain and Co- 
manche COS.), abundant in e., s.e. and n.-cen. Tex., infrequent in Rio Grande 
Plains, Edwards Plateau and Trans-Pecos, and Ariz. (Santa Cruz, Pima and Mo- 
have COS.), spring-fall; nat. of S. A., now rather widely distributed in warm-temp, 
areas n. to N. J., Tenn., Ark., Okla. and Ore. 

A persistent weed in lawns, almost impossible to eradicate once it has become 
established. It is an important forage plant. 

7. Paspalum laeve Michx. Fig. 146. 

Tufted perennial, very shortly subrhizomatous basally; culms 3-9 dm. long, 
about 2 mm. thick, erect, unbranched; ligule a brown scale 1-2 mm. long; blades 
6-40 cm. long, 3-10 mm. broad, flat or folded, glabrous or pilose; sheaths some- 
what keeled, glabrous or pilose; panicle axis 3-10 (-19) cm. long; racemes (2 to) 
3 to 6 (to 9), 3-11 cm. long, spreading, pilose in the axils; rachis about 1 mm. 
broad, dark-olive-green, with a zigzag central rib, the pedicels attached on this 
rib where it is nearest the margin, the narrow winglike margins interrupted; 
spikelets solitary, 2.4-3.1 mm. long, very broadly obovate to orbicular, pale or 
stramineous-olive, plano-convex, blunt; first glume always absent; second glume 
and sterile lemma firm-membranous, glabrous. P. longipilum Nash, P. circulare 
Nash. 

Sandy loam, prairies and open forests, wet pine barrens, -marshy ground along 
ditches and borders of lakes, ponds and bayous, wet savannahs, in Okla. 
(McCurtain Co.) and in e. and s.e. Tex. and extreme n.e. Rio Grande Plains 
(Nueces Co.), infrequent, summer-fall; Coastal States, Mass. to Tex. and inland 
to O., Ind., III., Mo., Kan. and Okla. 

8. Paspalum praecox Walt. Fig. 143. 

Tufted perennial, very shortly rhizomatous basally, culms 5-15 dm. long, 1-3 
mm. thick, erect, unbranched; ligule a brown scale 1-3 mm. long; blades 1-3 (-4) 
dm. long, 3-10 mm. broad, flat or usually folded, glabrous to pilose; sheaths 
glabrous to pilose, keeled; panicle axis 5-17 cm. long; racemes (2 to) 4 to 6 (to 
9), 2-7 (—9) cm. long, arcuate, ascending or spreading, shortly bearded and 
sometimes also pilose at the axils; rachis 1.3-2 mm. broad, purplish-olive, with a 
broad central rib to which the pedicels are attached, the marginal winglike por- 
tions firm and narrower than the central rib; spikelets paired or a few by abor- 
tion solitary on the same raceme, 2.2-3.2 mm. long, orbicular to suborbicular, 
yellowish-green, occasionally with a purplish-tinge, highly compressed plano- 
convex; first glume always absent; second glume and sterile lemma membranous, 
glabrous. P. lentiferum Lam. 

Sandy loam, open pine flats, in wet savannahs, cypress swamps, wet pine bar- 
rens and flatwoods, in s.e. Tex., infrequent, summer-fall; Coastal States, Va. to 
Tex. 

9. Paspalum lividum Trin. Longtom. Fig. 143. 

Tufted perennial; culms 50-175 cm. long, compressed, 2-4 mm. thick on the 
long axis, often basally decumbent and freely rooting for up to 1 m., then 
ascending at the floriferous ends; ligule a scale 1-3 mm. long; blades 10-23 cm. 

295 




Fig. 145: Paspaliini cUhitatum: a, floret, showing lemma, X 8; b, florel, showing 
palea. X 8; c, rachis, showing the 2 rows of hairy spikelets, X 4; d. habit, showing the 
noticeably pubescent lowest sheaths, the arching leaves and the spreading racemes, X '/-,; 
e, upper sheath, pubescent only around ligule and on base of blade, X 4. (From Mason, 
Fig. 78). 




Fig. 146: Paspalum laeve: plant, X Vs, two views of spikelet and floret, X 10. 
(From Hitchcock & Chase). 



long, 3-5 mm. broad, flat or folded; panicle axis 3-12 cm. long, curviflexuous; 
racemes 3 to 8, 15-50 mm. long, ascending and curved, floriferous to the base, 
the lower racemes with a few hairs in the axils: rachises 1.5-2.5 mm. broad, thin, 
purplish-olive to olive-purple, rather elongate, spreading, the rather elongate 
spreading pedicels attached along a very narrow central rib. the lateral portions 
of the rachis foliaceous and winglike and usually sparsely papillose-pilose mar- 
ginally; spikelets paired or rarely a few also solitary in the same raceme, (2.1-) 
2.3-2.7 (-2.9) mm. long, obovate, bluntly pointed, with nearly parallel plane 
surfaces or at least very compressed plano-convex, yellowish-green or occasionally 
with a purplish cast; first glume always absent; second glume and sterile lemma 
essentially glabrous. 

Moist tight clay loam in ditches, tanks, wet savannahs, swamps aqd flooded 
pasturelands, and in resacas and shallow lakes, s.e. Tex. and coastal parts of Rio 
Grande Plains, frequent, spring-fall; widespread in warmer parts of Am., n. to 
Ala., La. and Tex. 

10. Paspalum Hartwegianum Fourn. Fig. 147. 

Tufted stoloniferous perennial; floriferous culms 5-15 dm. long, slightly com- 
pressed, 2-5 mm. thick on the long axis, ligule a scale 1-3 mm. long; blades 
10-35 cm. long, 2-6 mm. broad, flat or folded; sheaths keeled; panicle axis 5-15 
cm. long, mostly straight and slender; racemes (3 or) 4 to 8, 2-9 cm. long, 
ascending or somewhat spreading, often slightly curved, floriferous to the base, 
the lower ones usually with a few long hairs in the axils; rachises 1.5-2 mm. 
broad, thin, olive or purplish-olive, the rather elongate spreading pedicels at- 
tached along a very narrow central rib. the lateral portions of the rachis foliaceous 
and winglike; spikelets paired, rarely also a few in the same raceme solitary, 
(2.2-) 2.5-2.9 (-3.2) mm. long, obovate, slightly pointed, with nearly parallel 
plane surfaces or at least very compressed plano-convex, yellowish-green; first 
glume always absent; second glume and sterile lemma shortly and uniformly 
pubescent. 

Moist tight soil, wet prairies, alkaline meadows, in mud and shallow water 
of irrigation ditches and streams, in the Tex. Rio Grande Plains, frequent, spring- 
fall; much of Mex. n.w. to Son.; Tex. 

11. Paspalum pubiflonim Fourn. Fig. 147. 

Loosely tufted perennial; culms 3-15 dm. long, compressed, 2-3 mm. thick 
on the long axis, decumbent and freely rooting in the basal third to half the 
length but usually mostly ascending; ligule a scale 1-3 mm. long; blades 6-30 
cm. long, 5-13 mm. broad, mostly flat, marginally crisped and basally papillose- 
pilose; lower sheaths usualy papillose-pilose; panicle axis 8-62 mm. long; racemes 
2 to 4 (to 6), 2-10 cm. long, ascending or spreading, floriferous to the base or 
infrequently with a naked basal portion 1-3 mm. long and a few long hairs in the 
axil; rachises 1.5-2 mm. broad, broadly triangular, olive-green; spikelets attached 
even along the margins, paired or rarely in the same raceme a few of them soli- 
tary, (2.3-) 2.7-2.9 (-3.2) mm. long, obovate, turgidly plano-convex, greenish 
to stramineous or with a purplish cast, blunt to very slightly pointed; first glume 
small, triangular, usually absent or much-reduced; second glume and sterile lemma 
microscopically pubescent to rarely glabrate. Incl. var. ghibrum Scribn. 

Moist garden loam and moist usually calcareous soil at edges of streams, ponds 
and lakes, along streams and irrigation ditches, in wet meadows, in Okla. (Hughes 
and Cherokee cos.), throughout Tex. (but rare in Plains Country), spring-fall; 
lowlands of s.e. U.S. n. to N.C., O.. Ind., 111.. Mo. and Kan.; much of Mex.; Cuba. 

12. Paspalum distichum L. Knotgrass. Fig. 148. 

Long-decumbent perennial; culms 5-15 dm. long, compressed, 2-3 mm. thick 
on the long axis, extensively creeping, freely rooting, somewhat branched, ascend- 

298 






Fig. 147: 1, Paspalum Hartwegianum: panicle, X 1; two views of spikelet and 
floret, X 10. 2, Paspalum acuminatum: panicle, X 1; two views of spikelet and floret, 
X 10. 3, Paspalum pubiflorum; panicle, X 1; two views of spikelet and floret, X 10. 
(From Hitchcock & Chase). 




Fig. 148: Paspalum (lisiichum: a. floret, showing palea. X 8; b, floret, showing 
lemma, X 8; c, rachis, showing 2 rows of spikelets, X 4; d, habit, showing the de- 
cumbent rooting base, the flat leaf blades and the paired racemes, X i/4; e, leaf sheath, 
ligule and node, densely pubescent, X 2'/2- (From Mason, Fig. 77). 



ing at the simple floriferous ends; ligule a scale 0.5-1 mm. long; blades 3-12 cm. 
long. 2-6 mm. broad, membranous and usually flat or folded, or the tip on drying 
loosely involute, basally broader than the summit of the sheath; sheaths slightly 
keeled at summit, the corner with a few soft hairs and often the lower sheaths 
(when emergent) visibly pubescent ("var. indutum") but these usually lost in 
specimens; racemes usually 2, rarely 1 or 3, 15-70 mm. long, erect or somewhat 
spreading, often arcuate, floriferous essentially to the base; rachises broadly 
triangular in transection, 1-1.5 (-2) mm. broad; spikelets attached nearly at the 
margin by the short pedicels, solitary, elliptic, (2.5-) 2.7-3 (-3.2) mm. long, 
greenish to stramineous, blunt to somewhat pointed; first glume usually present, 
minute, triangular; second glume microscopically pubescent; sterile lemma gla- 
brous or rarely with a few microscopic hairs near midrib. Incl. var. indutum 
Shinners. 

Margins of fresh ponds, streams and lakes, in marshes and on mud and in shal- 
low water, sometimes in brackish areas, in Okla. (Grady and Washita cos.), fre- 
quent in e., s.e. and n.-cen. Tex., Edwards Plateau and Trans-Pecos, infrequent 
in Rio Grande Plains and Plains Country, N. M. (Dona Ana and DeBaca cos.) 
and Ariz. (Pinal, Santa Cruz and Mohave cos.), summer-fall; widespread in the 
warmer parts of the world, in Am. n. to N. J., Tenn., Ark., Okla., Ut., Ida. and 
Wash. 

13. Paspalum vaginatum Sw. Fig. 149. 

Long-decumbent perennial; culms 5-25 dm. long, compressed, 3-4 mm. thick 
on the long axis, extensively creeping and freely rooting, branched, ascending 
only at the simple floriferous ends; ligule a scale about I mm. long; blades 2.5-15 
cm. long, 3-8 mm. broad, firm and stiffly straight, basally narrower than the 
summit of the sheath and folded, tapering to a long-involute tip (occasionally 
near semibrackish water the blades persistently flat); sheaths keeled, the corners 
ciliate; panicle axis 1-10 (-15) mm. long; racemes 1 or 2 (or 3), 2-8 cm. long, 
divaricate; rachises often naked for the basal 2-5 mm., 1-2 mm. broadly tri- 
angular or occasionally very narrowly winged; spikelets attached nearly at the 
margin by the broad short pedicels, solitary, ovate-elliptical, 3.1-4.2 (-4.5) mm. 
long, glabrous, stramineous, pointed; first glume very rarely present; sterile lemma 
thin and often transversely wrinkled; fruit pointed, nearly as long as spikelet, 
apically glabrous. 

Moist saline to brackish sands at edges of lagoons, bays and river-mouths, 
rarely in sub-brackish ponds near the coast, s.e. Tex. and Rio Grande Plains, 
frequent, summer-fall-early winter; widespread in warm coastal areas of the 
world, in Am., n. to N. C. and the Gulf States. 

14. Paspalum acuminatum Raddi. Fig. 147. 

Long-decumbent aquatic or subaquatic perennial; culms 3-10 dm. long, 1-3.5 
mm. thick, soft, freely rooting and rather freely branching, ascending and 
emergent only at the end; ligule a membranous scale 1-3 mm. long; blades 3-20 
cm. long, 2-12 mm. broad, flat, thin; panicle axis 1-3 cm. long; racemes 2 or 3 
(to 5?), 3-7 cm. long, ascending, usually somewhat arcuate; rachis 3-3.5 mm. 
broad, with the spikelets borne in a very narrow central rib, the remainder of 
the rachis forming foliaceous wings; spikelets solitary, elliptic, 3.3-3.5 mm. long, 
glabrous, greenish, apically abruptly pointed beyond the fruit; first glume absent; 
fruit blunt, apically with some minute cilia. 

In fresh water ponds or wet open ground, in the Tex. Rio Grande Plains, rare 
(Cameron and Brooks cos.), spring-fall; lowlands, widespread but scattered in 
trop Am., n. to s. La. and s. Tex. 

301 




Fig. 149: Paspalum vasinatum: a, habit, about X 1/2; b, ligule, X 1; c, portion of 
rachis, X 6; d, spikelet, X 10. (Courtesy of R. K. Godfrey). 






Fig. 150: Paspalum dissectum: a, habit, X I3; b, ligule, X 5; c, part of rachis with 
spikelets, X 6; d, two views of spikelet, X 10; e, floret, X 10. (Courtesy of R. K. 
Godfrey). 



15. Paspalum dissectum (L.) L, Fig. 150. 

Long-decumbent mat-forming perennial; culms 20-75 cm. long, compressed, 
1.5-2 mm. thick on the long axis, freely rooting in the mud, rather freely 
branched; ligule a membranous scale 1-2 mm. long; blades 2-9 (-12) cm. long, 
2-5 mm. broad, thin, flat or folded; panicle axis 3-8 cm. long, slender and 
grooved, 0.2-0.4 mm. thick; racemes 2 to 4, 1-5 cm. long, ascending and slightly 
arcuate; rachis 1.8-3 mm. broad, with the spikelets borne on a very narrow cen- 
tral rib, the remainder of the rachis forming foliaceous wings; spikelets solitary, 
broadly elliptic, 1.7-2 mm. long, 1-1.2 mm. broad, essentially glabrous, greenish 
to stramineous, apically blunt; first glume absent; fruit blunt. 

Forming mats in moist sand at the margins of seeps, bogs and lakes, on muddy 
and sandy banks of ponds and ditches or in shallow water, in Okla. (Okfuskee 
Co.) and e. Tex., infrequent, summer-fall; lowlands of s. U.S., n. to N.J. and 111.; 
Cuba. 

16. Paspalum fluitans (Ell.) Kunth. Fig. 151. 

Long-decumbent or floating aquatic grasses said to be annual; culms 3-10 dm. 
long, 2-5 mm. thick, soft (with much gas-holding tissue), mostly submerged, only 
the floriferous ends emergent; ligule a membranous scale 2-4 mm. long; aerial 
blades 10-25 cm. long, 9-20 mm. broad, very thin and flat; sheaths pubescent, 
their corners triangular-auricled; panicle axis 6-16 cm. long, 0.5-1 mm. thick; 
racemes (20 to) 30 to 50, 25-75 mm. long, ascending or usually arcuate- 
spreading, at maturity deciduous from the axis; rachis 1-1.7 mm. broad, the 
spikelets borne on a very narrow central rib, the remainder of the rachis forming 
thin foliaceous wings; spikelets solitary, 1.2-1.7 mm. long, only about 0.7-0.9 mm. 
broad, pubescent, pale-stramineous, often with a discolored or stained spot at the 
base of the sterile lemma and apically acute; first glume absent. P. repens Berg. 

Forming colonies in fresh water, in mud and water on edge of lakes, sloughs 
and ponds and floating in sluggish streams or standing water, in e. Okla. 
{Waterfall) and s.e. Tex., infrequent, summer-fall; widespread in trop. Am., n. to 
N.C., 111., Ind., Mo. and Neb. 

52. Panicum L. Panic Grass 

Annuals or perennials, widely diverse in habit; spikelets in panicles or less 
commonly in racemes (rarely in spikclike panicles and then sometimes with a 
bristle-like sterile branch subtending some spikelets); pedicels usually present; 
each spikelet falling as a unit, 2-flowered, the lower floret staminate or completely 
reduced, the upper perfect; first glume much shorter than the spikelet, several- 
nerved, membranous; second glume as long as the spikelet or nearly as long; lower 
"sterile" lemma several-nerved, membranous, usually as long as the spikelet or 
essentially so; sterile palea usually obsolete but occasionally (as in P. hians) 
very strongly developed and cupped and/ or hooded; fertile lemma usually some- 
what indurate, strongly convex, the margins rcvolute and clasping the palea of 
the same texture, usually smooth and shining like white cartilage, rarely trans- 
versely rugose. 

A large extremely complex genus (perhaps 500 species) of warm parts of the 
world, made particularly difficult in North America because of the occurrence of 
cleistogamy and occasional wide outcrossing among the "Dichantheliums" or 
dichotomous panic grasses. 

304 




Fig. 151: Paspalum fluitans: a, habit, X Vs; b, ligule, X 2; c, ligule, about X l^^; d, 
portion of rachis, X 10; e and f, two views of spikelet, X 12. (Courtesy of R. K. 
Godfrey). 



1. Basal leaves usually distinctly diflferent from those of the culm, forming a 
winter rosette; plants perennial, in spring producing simple culms 
with mostly narrowly lanceolate blades and terminal panicles with 
numerous spikelets (in most species these not producing viable 
seed); later culms often much-reduced and much-branched, produc- 
ing an autumnal phase usually quite different from the vernal 
phase and with reduced axillary panicles (2) 

1. Basal leaves similar to though usually smaller than those of the stem leaves; 

winter rosette absent; plants annual or perennial; spikelets usually 
nearly all fertile (9) 

2(1). Spikelets blunt and strongly nerved; blades rarely as much as 20 mm. 
broad 6. P. Ravenelii. 

2. Spikelets rarely if ever both blunt and strongly nerved (3) 

3(2). Ligule (or at least a ligulelike tuft at the extreme base of the blade) of 
conspicuous hairs usually (2-) 3-5 mm. long (4) 

3. Ligule less than 2 mm. long to obsolete (5) 

4(3). Spikelets 0.9-1.3 mm. long; "ligule" 2-3 mm. long 2. P. leucothrix. 

4. Spikelets 1.3-2.9 mm long; "ligule" (2-) 3-5 mm. long 3. P. lamiginosum. 

5(3). Spikelets nearly spherical at maturity; blades glabrous, firm, cordate; ligule 
obsolete 5. P. polyanthes. 

5. Spikelets usually obovoid or ellipsoid; ligule usually developed (obsolete in 

P. commutatum and allies) (6) 

6(5). Spikelets 2.3-3.2 mm. long (7) 

6. Spikelets 1.2-2.2 mm. long (8) 

7(6). Ligule obsolete; blade only 5-10 (-15) cm. long, 8-25 mm. wide, glabrous, 
at base cordate and ciliate; spikelets slenderly elHjwoid, 2.4-3.1 mm. 
long, never turgid 8. P. commutatum. 

I. Ligule a muticous scale or a short fringe; blades 10-23 cm. long, 9-30 rrfrn. 

wide, glabrous or scabrous, at base only slightly if at all cordate; 
spikelet turgidly ellipsoid to obovoid or ovoid, 2.3-3.2 mm. long 
7. P. scoparium. 

8(6). Culms delicate, usually less than 30 (rarely to 40) cm. tall; blades filmy, 

usually only 1-3 cm. long and 1-3 mm. wide, often reflexed 

4. P. ensifolium. 

8. Culms delicate or not so delicate, (15-) 20-100 cm. tall; blades firmer (mem- 

branous or more firm), 3-12 cm. long, 3-15 mm. wide, reflexed or 
ascending 1. P. dichotomwn. 

9(1). Plants annual (doubtful cases should be keyed under both alternatives) 
(10) 

9. Plants perennial (11) 

10(9). First glume about a fourth as long as the spikelet 

21. P. dichotomiflorum. 

10. First glume usually proportionately longer 20. P. capillare. 

11(9). Spikelets short-pedicelled along one side of the rachises to form spikelike 
racemes; fertile lemma transversely rugose (except in P. hemi- 
tomum) (12) 

II. Spikelets in open or sometimes contracted or congested panicles (somewhat 

1 -sided in P. anceps and P. rigidulum) (16) 

12(11). First glume nearly equaling the sterile lemma (13) 
12. First glume much shorter than the sterile lemma (14) 

13(12). Racemes spreading; fertile lemma not more than one third the total 
length of the spikelet 11. P. gymnocarpon. 

306 



13. Racemes appressed; fertile lemma nearly as long as spikelet 

13. P. obtusum. 

14(12). Fertile lemma not transversely rugose 12. P. hemitomum. 

14. Fertile lemma transversely rugose (15) 

15(14). Spikelets 2.2-2.4 mm. long 9. P. geminatum. 

15. Spikelets 2.5-3 mm. long 10. P. paludivagum. 

16(11). Sterile palea enlarged and indurate at maturity, expanding the spikelet; 
blades scarcely broader than their sheaths; spikelets about 2.3 mm. 

long, borne toward the ends of the few slender branches 

14. P. hians. 

16. Sterile palea usually absent or (if present) minute (17) 

17(16). Plants with conspicuous creeping scaly rhizomes (18) 

17. Plants without creeping scaly rhizomes (20) 

18(17). Spikelets short-pedicelled, more or less secund along the nearly simple 
panicle branches 15. P. anceps. 

18. Spikelets long-pedicelled, not secund, arranged in an open or contracted 

panicle (19) 

19(18). Panicle compact, strongly contracted, elongate and nodding; plants of 
coastal sands 18. P. amarulum. 

19. Panicle diffuse or only slightly contracted 19. P. virgatum. 

20(17). Panicles narrow and few-flowered; culms erect and wiry; blades drying 
involute 17. P. tenerum. 

20. Panicles open or contracted, many-flowered 16. P. rigidulum. 

1. Panicum dichotomum L. Fig. 152. 

Perennial; vernal phase (Apr.-Aug.) culms tufted, erect or ascending from 
a knotted or loose crown, 3-5 (-10) dm. tall, glabrous but the nodes very often 
with a grayish retrorse beard about 1 (-2) mm. long and often the lower nodes 
geniculate; sheaths essentially glabrous; ligules minute; blades usually spreading, 
the upper often reflexed, 3-12 cm. long, 4-15 mm. broad, glabrous or sparsely 
papillose-ciliate at base, green (often bright, rarely olivaceous) and thin, quite 
flat; panicle usually elongate-ovoid, usually many-spikeletted, 5-12 cm. long, 
with the slightly spreading very slender and often flexuous branches usually 
copiously branched; spikelets 1.4-2.2 mm. long, elliptic, glabrous or pubescent, 
5- to 7-nerved; second glume usually shorter than fertile lemma; autumnal phase 
(June-Dec.) much-reduced, much-branched at some nodes, the lower part usually 
ascending (or reclining from the heavy weight of the top) and bladeless like a 
slender tree-trunk, the upper part copiously bushy-branched with numerous small 
blades 2-4 cm. long and 1-3 mm. broad (thin, green, flat or often involute). 
P. nitidum Lam., P. barbulatum Michx., P. microcarpon Muhl., P. lucidum Ashe, 
P. yadkinense Ashe. 

In swampy and marshy grounds, bogs, wet peaty meadows and margins of 
streams, also in moist sandy woodlands, in Okla. (LeFlore Co.) and in e. and s.e. 
Tex., rare w. to n.-cen. Tex., spring-fall; s.e. Can., e. U.S., Bah. I., Cuba. 

2. Panicum leucothrix Nash. Fig. 152. 

Perennial; vernal phase light olive-green to dark-green; culms 1-5 (-7) dm. 
tall, ascending (often decumbent at base and somewhat geniculate) weak, slender, 
glabrous or appressed papillose-pilose, the nodes pubescent or glabrous; sheaths 
papillose-pilose to puberulent or glabrous; ligule minute but blade at base with 
a ligulelike tuft or hairs 2-3 mm. long; blades 3-8 mm. broad, about 2-5 cm. 
long, glabrous or sparsely villous above, puberulent or glabrous beneath, or even 
velvety-puberulent beneath; panicle 3-8 cm. long, rather densely flowered; spike- 

307 




Fig. 152: 1, Panicum dichotomiim: plant, X V-y, two views of spikelet, and floret, 
X 10. 2, Panicum leucothrix: two views of spikelet and floret, X 10. 3, Panicum poly- 
anthes: two views of spikelet and floret, X 10. 4, Panicum Ravcnelii: two views of 
spikelet and floret, X 10. (From Hitchcock & Chase). 





Fig. 153: 1, Panicum commutatum: plant, X 1; two views of spikelet and floret, 
X 10. 2, Panicum laniiginosum: plant, X 1; two views of spikelet and floret, X 10. 
(From Hitchcock & Chase). 



lets 0.9-1.3 mm. long, pubescent, elliptic; autumnal phase: stems reclining or 
decumbent-spreading, occasionally the culms at first sending out from lower and 
middle nodes long branches similar to primary culms, later producing more or 
less fascicled branches, or usually the culms with crowded branchlets, the whole 
somewhat bushy-branched; blades flat or subinvolute. P. Wrightianum Scribn., 
P. longiligulatum Nash. 

Infrequent in sandy woodlands, often in boggy or moist low places, in pine 
barrens and swamps, in e. and s.e. Tex., spring-fall; Coastal States, Mass. to Tex.; 
also Tenn.; W.I., C.A., Col. 

3. Panicum lanuginosum Ell. Fig. 153. 

Perennial; vernal phase (usually grayish) olive-green or bluish-green, velvety- 
villous to densely spreading-villous throughout or the upper parts of the culm or 
the various parts of the leaves glabrate; culms usually in large clumps, 2-7 dm. 
tall, spreading, often with a glabrous ring below the nodes, the nodes themselves 
usually with a retrorse gray beard; sheaths like the midstems in pubescence; 
ligule a short fringe but blade at base with a ligulelike tuft of hair 3-5 mm. long; 
blades thickish, sometimes stiff, often somewhat incurved or spoon-shaped (when 
fresh), from nearly glabrous to densely velvety or densely villous, 4-10 cm. long, 
5-12 mm. broad, sometimes with a very thin firm margin; panicle (4-) 6-12 cm. 
long, the axis and also often the branches pubescent; spikelets 1.6-2.1 mm. long, 
pubescent, 5- to 9-nerved; autumnal culms widely spreading to matted-decumbent 
or ascending or rarely erect, freely branching from the middle nodes, the branches 
repeatedly branching and much-exceeding the internodes, the ultimate branchlets 
forming flabellate fascicles; blades much-reduced, 2-3 cm. long, usually much- 
exceeding the panicles. P. Thurowii Scribn. & Sm. 

In wet meadows, swales, seepage areas, and wet soil along streams, about ponds 
and lakes, in sandy woodlands and prairies, in Okla. {Waterfall), e. half of Tex., 
to Ariz. (Pima Co.), spring-fall; N. S. and Que. to Mont., s. to Gulf States, 
N.M., Ariz, and Calif, (rare w. of the 100th meridian). 

4. Panicum ensifolium Ell. Fig. 154. 

Perennial, glabrous throughout; vernal culms 2-4 dm. tall, erect or reclining; 
ligule a very minute fringe or obsolete; blades distant, often reflexed, 1-3 cm. 
long, 1.5-3 mm. broad, puberulent beneath (at least toward the tip); panicle 
15-40 mm. long; spikelets 1.2-1.7 mm. long, glabrous or puberulent, 5- to 7- 
nerved; autumnal culms spreading or reclining, sparingly branching from the 
middle nodes, the branches mostly simple. 

Rare in moist sand, boggy soil and shady wettish places, in e. Tex. (Nacog- 
doches and Newton cos ), spring-fall; Coastal States, N. J. to Tex. 

5. Panicum polyanthes Schult. Fig. 152. 

Perennial, completely glabrous (except spikelets); vernal culms erect, 3-9 dm. 
tall, the nodes glabrous or nearly so; ligules absent or a minute fringe in 
genetically contaminated plants; blades 12-33 cm. long, 15-25 mm. broad, firm, 
cartilage-margined, at base cordate and ciliate. the upper scarcely reduced; panicle 
8-25 cm. long, a fourth to half as wide as long, densely flowered, the branches 
mostly viscid; spikelets 1.3-1.8 mm. long, minutely puberulent, obovoid-spherical 
at maturity, broadly ellipsoid when young, 5- to 7-nerved; autumnal phase remain- 
ing erect, producing simple branches from the lower and middle nodes, the thick 
white-margined blades of the winter rosette conspicuous. 

In shallow water of streams, in seepage areas and in sandy moist woodlands, 
in Okla. (McCurtain Co.) and in e. Tex., spring-fall; s.e. U.S. n. to Conn., Pa., 
III., Mo. and Okla. 

310 




3 





1 




Fig. 154: 1, Panicum ensifoUum: plant, X 1; two views of spikelet and floret, X 10. 
2, Panicum amanilum: two views of spikelet and floret, X 10. 3, Panicum anceps: 
spikelet and floret, X 10. 4, Panicum rigidulum: panicle, X 1; two views of spikelet and 
floret, X 10. (From Hitchcock & Chase). 



6. Panicum Ravenelii Scribn. & Merr. Fig. 152. 

Perennial; vernal culms fairly stout and erect, 3-7 dm. tall, densely papillose- 
hirsute with ascending hairs, the nodes short-bearded; sheaths hirsute like the 
culms; ligule a fringe or tuft 3-4 mm. long, on the larger leaves grading into 
additional tuft at blade base; blades thick and firm, 8-15 cm. long, 1-2 cm. broad, 
glabrous above, densely velvety-hirsute beneath; panicle 7-12 cm. long; spikelets 
3.7-4.3 mm. long, sparsely papillose-pubescent, strongly 7- to 9-nerved: autumnal 
phase more or less spreading, branching from the middle and upper nodes, the 
short branches crowded at the summit. 

Sandy woodlands, in wet sandy loam, and in water and mud of lakes and ponds, 
in Okla. (Cherokee and Haskell cos.) and e. and s.e. Tex., spring-fall; Del. to 
Mo., s. to Fla. and Tex. 

7. Panicum scoparium Lam. Fig. 155. 

Perennial; vernal phase grayish-olive-green, velvety-pubescent throughout except 
on a viscid ring below the nodes and at the summit of the sheath; culms 8-15 
dm. long, stout, usually 2-3 (-4) mm. thick, erect or ascending, usually genicu- 
late basally, sometimes scabrous below the nodes, sometimes puberulent; sheaths 
glabrous or hispid, often mottled or white-spotted, commonly swollen basally and 
contracted upward; ligule a fringe 0.5-1.3 (-1.4) mm. long (more than 1 mm. 
long only in the best-developed leaves); blades rather thick, 12-25 cm. long, 9-18 
mm. broad, often stiffish, ascending or spreading, glabrous or scabrous, sometimes 
more or less pubescent beneath; panicle 8-20 cm. long, the axis and branches 
with viscid blotches or these absent; spikelets 2.3-2.6 mm. long, ovate to obovate, 
turg'd, papillose-pubescent to obscurely puberulent to glabrous, pointed (not 
sharply), 7- to 9-nerved; autumnal phase erect, leaning or spreading, freely 
branching from the middle and upper nodes, forming flabellate fascicles. P. 
scabriusculum Ell. 

Sandy woodlands, usually in moist or even boggy areas, in swamps, marsh- 
meadows, and wet soil along ditches, streams and about ponds, in Okla. (LeFlore 
Co.) and e. and s.e. Tex., spring-fall; Mass. to Fla. w. thorugh Ky. to Mo., Okla. 
and Tex.; Cuba. 

8. Panicum commutatum Schult. Fig. 153. 

Perennial; vernal culms erect or decumbent often from somewhat knotty bases, 
25-75 cm. long, sometimes purplish-tinged; nodes never bearded; sheaths glabrous 
or nearly so; ligule a minute scale or usually essentially absent; blades 5-10 (-15) 
cm. long, (6-) 8-25 mm. broad, glabrous on both surfaces but often slightly 
cordate and marginally ciliate near base; panicle 5-12 cm. long, loosely flowered, 
not much or often incompletely exserted from the upper sheath; spikelets 2.4-3.1 
mm. long, 7- to 9-nerved, pubescent, ellipsoid, not very turgid; autumnal culms 
erect or leaning, often widely spreading, not much-branched, the winter rosette 
leaves often with a minute cartilaginous margin. P. Joorii Vasey, P. Ashei Pearson. 

Low or swampy woods in Okla. (Waterfall) and e. Tex.; e. U.S. w. to Mo., 
Okla. and Tex.; Mex. 

9. Panicum geminatum Forsk. Fig. 156. 

Perennial, glabrous; culms terete, tufted, 25-80 cm. long, rarely decumbent 
basally and rooting at the nodes, usually slightly geniculate basally and essentially 
erect; blades 1-2 dm. long, 3-6 mm. broad, flat or toward the apex involute; 
panicle 12-30 cm. long, extremely narrow; appressed spikelike racemes (3 to) 
8 to 18, lower racemes 25-30 mm. long, upper gradually shorter; raceme rachis 
ending in a short naked point; spikelets 2.2-2.4 mm. long, 5-nerved, subsessile, 
abruptly pointed, glabrous, the first glume truncate; fertile lemma and palea 

312 




Fig. 155: Panicum scoparium: a, basal part of plant, X %; b, middle section of 
stem, X Vz; c, upper part of plant, X Mj; d, ligule, about X 2; e and f, two views of 
spikelet, X 10. (Courtesy of R. K. Godfrey). 



transversely rugose. Paspalidium geminatum (Forsk.) Stapf. 

Moist or wet ground or in shallow water, in Okla. (Jefferson Co.) and in e. 
half of Tex., frequent nearest the coast, summer-fall; Fla., La., Tex., Okla. and 
warmer regions of the world. 

10. Panicum paludivagum Hitchc. & Chase. Fig. 157. 

Perennial; vernal culms erect or decumbent often from somewhat knotty bases, 
creeping, rooting, rather succulent, as much as 2 m. long, the lower part often 
submerged, loosely branching; blades 15-40 cm. long, scabrous on the upper sur- 
face; spikelets 2.5-3 mm. long, faintly 3-nerved; fertile lemma obscurely to ob- 
soletely transversely rugose. Paspalidium paludivagum (Hitchc. & Chase) Parodi. 

Scattered in wet places, in shallow water of ponds, lakes and streams, in 
s. Tex. (Cameron, Hidalgo, Brazoria and San Patricio cos.), summer-fall; Fla., 
Tex., Mex.; Guat. 

This is not adequately separable from P. geminatum, being scarcely more than 
a form of that species. 

11. Panicum gymnocarpon Ell. Fig. 158. 

Perennial, rooting at the lower nodes; culms basally prostrate, terminally ascend- 
ing, 3-7 mm. thick; blades 14-25 mm. broad, basally with pronounced corners, 
marginally finely serrate; ligule a thin scale 1 mm. long; inflorescence panicu- 
loid, 12-40 cm. long, 7-25 cm. broad, of 14 to 35 loosely ascending remote or 
remotely whorled branches ("racemes" of some descriptions) with each secundly 
bearing a number of closely set appressed nearly sessile spikelets or (toward the 
base) usually compound with short appressed secondary branchlets (each bearing 
several appressed sessile spikelets); spikelets 5.5-7 mm. long, narrow; first glume 
nearly as long as the sterile lemma, the second glume strongly 3- to 5-nerved 
and surpassing the sterile lemma, both of them acuminate and glabrous; fertile 
lemma 2 mm. long, smooth, shiny. 

Local in wet sand along streams or in shallow water, in mud about lakes and 
ponds, in e. and s.e. Tex. (w. to Anderson and Colorado cos.), fall; Coastal 
States, S.C. to Tex. and inland to Ark. 

12. Panicum hemitomon Schult. Maidencane. Fig. 159. 

Aquatic or subaquatic perennial from extensively creeping rhizomes, often 
producing numerous sterile shoots with overlapping sometimes densely hirsute 
sheaths; culms 5-15 dm. tall, usually hard; sheaths of fertile culms usually gla- 
brous; blades 10-25 cm. long, 7-15 mm. broad, usually scabrous on the upper 
surface and smooth beneath; panicles elongate, very narrow. 15-30 cm. long, the 
branches erect, the lower branches distant, the upper ones approximate, 2-10 cm. 
long; spikelets subsessile, 2.4-2.7 mm. long, lanceolate, acute, 3- to 5-nerved, 
glabrous; first glume about half the length of the spikelet; fertile lemma less 
indurate than usual in Panicum; apex of fertile palea scarcely enclosed by the 
margin of the fertile lemma. 

Frequent (rarely flowering) on margin of lakes, ponds and streams, and in 
shallow water of lakes and ponds, in e. and s.e. Tex., spring (usually May); 
Coastal States, N.J. to Tex.; also Tenn.; Braz. 

13. Panicum obtusum H.B.K. Vine-mesquite. Fig. 160. 

Perennial forming large colonies from extensive stolons; culms in tufts from 
a knotty base at intervals along the stolon, wiry, compressed, 2-8 dm. tall; ligules 
about 1 mm. long; blades mostly elongate, 2-7 mm. broad, glabrous or nearly 
so; panicles narrow, 3-12 cm. long, about 1 cm. broad, the few appressed 
branches densely flowered, the short pedicels sccund; spikelets 3-3.8 mm. long, 
obovoid, brownish, blunt, scabrous; first glume nearly as long as the spikelet; 

314 




Fig. 156: Panicum geminatum: plant, X V2', two views of spikelet and floret, X 10. 
(From Hitchcock & Chase). 




Fig. 157: Paniciim palncUvapum: a, habit, X if;; b, ligiile, X 4; c, spikelet showing 
1st glume, X 7; d, spikelet showing 2nd glume, X 7; e, palea of staminate flower, X 7; 
f, floret showing palea, X 7; g, floret showing lemma, X 7. (Courtesy of R. K. Godfrey). 



fertile lemma smooth and shiny. 

In marshes, seepage areas, about playa lakes, along sloughs, often forming large 
colonies near water or in sporadic overflow areas, in Okla. (Waterfall), the w. 
half of Tex., e. to n.-cen. Tex. and the Coastal Bend area, N. M. (Colfax and 
Valencia cos.) and Ariz, (throughout the state), spring-fall; Mo. to Colo., s. to 
Ark. and cen. Mex. 

14. Panicum hians Ell. Fig. 161. 

Tufted perennial; culms compressed, 2-6 dm. tall, mostly erect, sometimes 
more or less decumbent or prostrate with erect branches; ligules minute; blades 
5-15 cm. long, 1-5 mm. broad, flat or folded, pilose on the upper surface near 
base; panicles 5-20 cm. long, usually loose and open, the primary branches few, 
slender, distant, spreading or drooping, the branchlets borne on the upper half 
or toward the ends only; spikelets in more or less secund clusters, short-pedicelled, 
2.2-2.4 mm. long, 5-nerved, glabrous; palea of the sterile floret becoming enlarged 
and indurate, expanding the spikelet to twice as thick as wide at maturity; fertile 
lemma minutely papillose-roughened, relatively thin for this genus. 

Usually in low places, damp soil, in swamps, marshes, seepage areas, bogs, 
sloughs and about ponds and lakes, Okla. (LeFlore, McCurtain, Atoka and John- 
ston COS.) and e., s.e. and n.-cen. Tex. and Rio Grande Plains, rare w. to Llano 
region, spring-fall; Coastal States, Va. to Tex.; also Mo., Ark., Okla. and Mex. 

15. Panicum anceps Michx. Fig. 154. 

Perennial from branching scaly rhizomes 2-4 mm. thick; culms 3-10 dm. long, 
erect, compressed; sheaths keeled, glabrous to pilose or densely to sparsely villous 
(especially at summit); ligule a scale 0.2-0.6 mm. long, firm; blades elongate, 
4-12 mm. broad, pilose near base or often pubescent on both surfaces; panicles 
15-40 cm. long, the branches ascending or spreading, slender, remote, bearing 
short mostly appressed rather densely flowered branchlets; spikelets slightly oblique 
to the pedicels, 2.4-3.8 mm. long, short-pedicelled, lanceolate, pointed, glabrous, 
often gaping; sterile lemma 5- to 7-nerved; glumes and sterile lemma mostly 
keeled; fertile lemma smooth and shiny and with a very minute tuft of thickish 
hairs at apex. P. rhizomatum Hitchc. & Chase. 

Abundant in sandy well-drained usually forested uplands, in wet prairies, 
swampy meadows, and on edge of streams and ponds, in Okla. (Pushmataha Co.) 
and in e. and s.e. Tex., infrequent w. to n.-cen. Tex., late summer-fall; s.e. U.S. 
w. to Kan., Okla. and Tex. 

16. Panicum rigidulum Nees. Fig. 154. 

Tufted perennial in dense clumps from a short multinoded crown, with numerous 
short-leaved innovations at base; culms 5-10 dm. tall, erect, compressed; sheaths 
keeled; ligules membranous, about 1 mm. long or less; blades erect, folded basally, 
flat distally, 2-5 dm. long, 5-12 mm. broad, glabrous or sparsely pilose on the 
upper side at the folded base; panicles terminal and axillary, 1-3 dm. long, a 
fifth to nearly as broad as long, the long branches erect or spreading, naked at 
base, the appressed to spreading densely flowered branchlets mostly borne on the 
underside of the branches, the pedicels glabrous or bearing near the summit 1 or 
several hairs; spikelets 1.8-2.8 mm. long, short-pedicelled, lanceolate, pointed, 
glabrous; sterile lemma 5- to 7-nerved; glumes and sterile lemma mostly keeled; 
fertile lemma and palea smooth and shiny, the fertile lemma sessile or rarely 
with a very minute stipe and with a minute tuft of thickish hairs at apex. P. 
agrostoides Spreng. and var. ramosius (Mohr) Fern., P. condensum Nash, P. 
stipitatum Nash. 

317 




Fig 158: Panicum gymnocarpum: a and b, habit, X ^i; c, iigule, X %; d, spikelet, 
X 5. (Courtesy of R. K. Godfrey). 




Fig. 159: Panicum hemitomon: a, habit, X V^; b, ligule, X 3; c, spikelet showing 
2nd glume, X 10; d, spikelet showing 1st glume, X 10. (Courtesy of R. K. Godfrey). 



Abundant in moist or poorly drained areas, in wet meadows, on muddy banks 
of ponds, lakes and streams, in shallow water of ponds and lakes, swampy areas 
and along sloughs, in Okla. (McCurtain, Adair, Atoka, LeFlore, Osage and 
Mayes cos.) and e. and s.e. Tex., infrequent w. to n.-cen. Tex., late summer-fall; 
most of e. U.S.; W.I.; Coah. 

17. Panicum tenerum Beyr. Fig. 161. 

Perennial from knotty crowns; culms several, subcompressed, wiry, erect, 4-9 
dm. tall; lower sheaths pubescent toward the summit, with spreading hairs; ligule 
minute; blades 4-15 cm. long, 2-4 mm. broad, erect, firm, subinvolute, pilose on 
upper surfaces toward the base; panicle 3-8 cm. long, very slender, terminal and 
axillary; spikelets short-pedicelled (the pedicel usually with a few long hairs), 
2.2-2.8 mm. long, pointed, glabrous; fertile lemma and palea smooth and shiny. 

Rare in wet places, margins of swamps and wet places in pine barrens, in 
s.e. Tex., rarer still in e. Tex., summer-fall; Coastal States, N.C. to Tex.; W.I. 

18. Panicum amanilum Hitchc. & Chase. Beach panic. Fig. 154. 

Perennial from extensive decumbent subrhizomatous to rhizomatous bases, 
forming clumps as much as 3 m. across; ascending aerial portions of the numerous 
culms to 1 m. long and 1 cm. thick, glaucous, glabrous throughout; ligule a fringe 
about 2 mm. long or at the extreme base of the fringe a firm minute scale; 
blades linear, firm, 2-5 dm. long, 5-12 mm. broad, involute near the tip, pilose 
on the upper surface near the base; panicle large, rather compact, 3-10 cm. 
broad, slightly nodding, densely flowered; spikelets 4.3-5.5 mm. long, acuminate- 
pointed, glabrous; sterile lemma strongly 5- to 9-nerved; lower floret staminate; 
fertile lemma and palea smooth and shiny. 

All along the Gulf beaches in loose dune sand, also on margin of swamps and 
wet places in pine barrens, fall; beaches, N.J. to Mex.; W.I. 

Very doubtfully distinct from P. amarum Ell., which occurs on beaches from 
Connecticut to Georgia, and has been reported to occur in Texas. P. ainanim 
supposedly differs in more definitely rhizomatous habit, with culms rising singly 
at intervals, panicle a fourth to a third the entire height of the plant and not 
more than 3 cm. broad and spikelets 5-6.5 mm. long. 

Panicum amanilum intergrades with P. virgatum inland. 

19. Panicum virgatum L. Switchgrass. Fig. 162. 

Perennial from strong branching scaly horizontal rhizomes; culms stout, robust, 
in large bunches, green or glaucous, tough, 1-2 (-3) m. tall; sheaths glabrous; 
ligule membranous, ciliate; blades 1-6 dm. long, 3-15 mm. broad, flat, glabrous or 
sometimes pilose above near base, rarely pilose all over; panicle 15-50 cm. long, 
open and diffuse; spikelets turgid, often gaping, glabrous, (2.8-) 3.5-5 mm. long, 
acuminate-pointed; first glume clasping, two thirds to three fourths as long as the 
spikelet, acuminate or cuspidate; sterile lemma 5- to 9-nerved; lower floret usually 
staminate; fertile lemma narrowly ovate, smooth and shiny, the margins inrolled 
only in the lower part. 

In moist or seasonally moist open places, fresh or brackish marshes, seepage 
areas, swamps about lakes, edge of ponds and in shallow water of pools, in Okla. 
(Ottawa, Woodward, Creek, LeFlore and McCurtain cos.), nearly throughout 
Tex. but infrequent or rare in the Trans-Pecos, and N. M. (Colfax, Guadalupe 
and Quay cos.), late summer-fall; N.S. and Ont. to N.D. and Wyo., s. to Gulf 
States; Cuba; reported in Jal. and Gro. but perhaps based on misdeterminations; 
reports of its occurrence in Coah. and Chih. are based on specimens of P. bulbo- 
sum. 

320 




Fig. 160: Panicum obtusum: plant, X V2, spikelet and floret, X 10. (From Hitch- 
cock & Chase). 






Fig. 161: a and b, Panicum hians: a, top of plant, X %; b, spikelet, X 10. c-e, 
Panicum tenerum: c, habit, X !^; d, ligule, X 2; e, two views of spikelet, X 7. (Courtesy 
of R. K. Godfrey). 



20. Panicum capillare L. Witchgrass. Fig. 163. 

Annual, freely branched from the base; culms usually somewhat spreading from 
the base, 2-8 dm. long, papillose-hispid to rarely nearly glabrous; sheaths hispid; 
ligule 1-3 mm. long; blades 10-25 cm. long, 5-15 mm. broad, hispid on both 
surfaces; panicles many-flowered, diffuse, often making up half the total length 
of the plant, included at base until maturity, the branches finally divaricately 
spreading, the whole panicle breaking away and rolling before the wind; spike- 
lets 2-3.3 mm. long, pointed or attenuate at the tip, 7- to 9-nerved, glabrous; 
first glume large, clasping; fertile lemma and palea smooth and shining, usually 
olive-brown at maturity. Incl. var. occidentale Rydb. 

Moist soil in waste and cultivated lands, along irrigation ditches, and in wet 
sandy places along streams, about playa lakes and low alluvial soils in Okla. 
(Alfalfa Co.) and in the Tex. Trans-Pecos and Plains Country, infrequent e. to 
n.-cen. Tex. and N. M. (San Miguel and Sierra cos.), often in disturbed ground, 
summer-fall; most of N.A. 

21. Panicum dichotomiflorum Michx. Fall panic. Fig. 164. 

Somewhat succulent branching annual; culms ascending or spreading from a 
geniculate base, 5-10 dm. tall or in robust specimens to 2 m. long; ligule a 
dense ring of white hairs 1-2 mm. long; blades flat, scaberulous and sometimes 
sparsely pilose on the upper surface, 1-5 dm. long, 3-20 mm. broad, the white 
midrib usually prominent; panicles many-flowered, terminal and axillary, mostly 
included in the upper sheath at the base, 1-4 dm. long or more, the main branches 
rather stiff, ascending, the branchlets short and appressed along the main branches; 
spikelets short-pedicelled, narrowly oblong-ovate, 2-3 mm. long, acute, 7-nerved, 
glabrous; first glume only about a fourth as long as the spikelet; fertile lemma 
smooth and shining. 

Moist ground along streams and in disturbed soil, marshy areas, in sluggish 
streams and seepage areas, in Okla. (McCurtain, Nowata, Kay and Pittsburg 
COS.) and in e. half of Tex., more common in low areas near the coast such as 
rice fields, rare in e. part of Plains Country, late summer-fall; N.S. and Me. to 
Minn., s. to Fla. and Tex., occasionally introd. farther w.; W.I. 

53. Sacciolepis Nash 
A genus of about 30 species in warm regions. 
1. Sacciolepis striata (L.) Nash. Fig. 165. 

Perennial; culms extensively creeping, the lower internodes 2-4 mm. thick; 
sheaths usually shortly papillose-pilose; ligule obsolete; blades with conspicuous 
nervature; panicles terminal, not much-exserted, spiciform, 6-15 (-25) cm. long, 
about 1 cm. thick, with numerous appressed branches, the minute ultimate pedicels 
abscising just below the glumes; spikelets not much-compressed, 2-flowered, the 
lower floret staminiferous, the upper perfect; rachilla abscising just below the 
fertile lemma; first glume minute, triangular, 3- to 5-nerved; second glume lanceo- 
late, gibbous basally, 4-5 mm. long, strongly several-nerved; lower lemma as 
long as the second glume, with obscure nerves and a well-developed palea and 
3-stamens; fertile lemma about half as long as the spikelet, very thin-cartilaginous, 
oblong, blunt, the margins revolute, enclosing the palea of the same texture. 

In moist sands near streams, marshes and bogs, in shallow water of lakes and 
ponds, in Okla. (Johnston Co.) and infrequent to rare in e. and s.e. Tex. (Jasper 
Marion, Houston, Cherokee and Wood cos.), late summer-fall; Coastal States, 
N. J. to Tex.; Okla. and Tenn. 

323 




Fig. 162: Panicum virgatum: plant, X Vs, two views of spikelet and floret, X 10. 
(From Hitchcock & Chase). 




Fig. 163: Panicum capillare: plant, X l->; two views of spikelet and floret. X 10. 
(From Hitchcock & Chase). 



54. Echinochloa Beau v. Water Grass 

Annual or rarely perennial; culms rarely erect, often rooting at the nodes; 
leaves membranous, flat; ligule absent in most species; inflorescence an elongate 
terminal panicle of numerous ascending spikelike branchlets that are secundly 
flowered on the abaxial side; spikelets paired in the upper nodes of the spikelike 
branchlets and in several-flowered secondary panicles in the lower part, not at 
all compressed, 2-flowered (the lower floret usually completely reduced, rarely 
staminiferous), turgidly plano-convex; first glume about half as long as the 
spikelet, acute; second glume and sterile lemma membranous, equal, about as 
long as the spikelet, usually stiffly hispidulous along the several nerves, acute; 
glume usually coarsely mucronate or awned (if awned, the awn of the second 
glume much longer than that of the first); sterile lemma enclosing a thin palea 
and rarely 3 stamens and often awned; fertile lemma broadly elliptical, cartilagin- 
ous-indurate, acuminate, the lateral margins revolute, clasping the lateral margins 
of the similarly textured palea but not its acute free tip. 

A genus of perhaps 25 species of warm regions. They are excluded from 
Panicum on the bases of the form of the inflorescence, the usually very coarsely 
pubescent spikelets and the coarsely mucronate or awned glumes. Probably they 
represent merely a part of the very diverse genus Panicum, and should be placed 
therein. These plants are commonly found in muddy places and provide good 
forage locally. 

The seeds of these species provide imjwrtant food for ducks and many other 
kinds of birdlife. 

1. Ligule a row of stiff yellowish hairs; body of sterile lemma 4-5 mm. long.... 
5. E. polystachya. 

1. Ligule obsolete or absent; body of sterile lemma 2.5-4 mm. long (2) 

2(1). "Spikes" of inflorescence 3-20 (-40) mm. long, ascending, often diverging 
from the axis at angles of 20°^5°, only shortly if at all overlap- 
ping; blades 3-6 mm. broad 1. E. colonum. 

2. "Spikes" of inflorescence 10-100 mm. long, ascending or slightly diverging, 

often overlapping a considerable portion of their lengths; blades 
mostly broader than 5 mm. (3) 

3(2). Inflorescence thick, if slender then erect; sterile lemmas unawned or with 
awns to 10 mm. long 2. E. crusgalli. 

3. Inflorescence slender, nodding, dense; sterile lemmas with awns ,4—43 mm. 

long (4) 

4(3). Sheaths usually papillose-pilose or papillose-hispid; spinulose cilia of the 
nerves of the second glume and sterile lemma conspicuously papil- 
lose 4. E. Walteri. 

4. Sheaths glabrous; spinulose cilia of the nerves of the second glume and sterile 

lemma not conspicuously papillose 3. E. cruspavonis. 

1. Echinochloa colonum (L.) Link. Jungie-rice. Fig. 166. 

Diffuse annual; culms erect or procumbent and rooting at the nodes. 1-2 (-3) 
mm. thick basally; ligule obsolete; "spikes" 3-20 (-40) mm. long, ascending, 
appressed or often diverging from the axis at angles of 20°— 45°, remote on the 
axis, only shortly if at all overlapping; second glume and sterile lemma simply 
strongly acuminate, not awned, hispid along the nerves (use lens), about 3 mm. 
long. Panicum colonum L. 

In water of freshwater canals, ditches and pools, in marshes, Okla. (McCurtain, 
Johnston and Cherokee cos.), nearly throughout Tex. (infrequent in Plains 
Country) in moist loamy often disturbed soil, N. M. (Lea and San Juan cos.) and 
Ariz. (Yavapai, Graham, Pinal, Maricopa, Cochise, Santa Cruz, Pima and 

326 




iiiliiilnilil iliiiliiiliiilill 



Fig. 164: Panicum dichotomiflorum: A, habit, x i/^; B, spikelet, showing the dicho- 
tomous florets, x 7; C, ligule, x 4; D, caryopses, x 7. (From Reed, Selected Weeds of 
the United States, Fig. 35). 




Fig. 165: Sacciolepis striata: a-c, habit, X 'A; d and e, two views of spikelet, X 14. 
(a-c, V. F.; d and e, Courtesy of R. K. Godfrey). 



Yuma COS.), summer-fall; nat. to the Old World trop., now widespread in warm 
regions of the world. 

2. Echinochloa crusgalli (L.) Beauv. Barnyard grass. Fig. 167. 

Erect or diffuse annual; culms 2.5-10 mm. thick basally; sheaths smooth; ligule 
obsolete; panicle erect or slightly nodding; "spikes" 1-10 cm. long, ascending, 
lengthily overlapping, often with stiff bristlelike hairs; second glume and sterile 
lemma mucronate or awned, the nerves hispid or spinose-hirsute, 2.5—4 mm. long. 
Panicum crusgalli L. 

Nearly throughout our area in moist often disturbed loamy soil, in marshes, 
seepage areas, and in mud and water of lakes, ditches and floodplains, summer- 
fall; widespread in temp, and trop. areas of the world. 

Variable species; we have two fairly well-marked but intergrading varities: 

Var. crusgalli, with long, somewhat spreading, papillose cilia at the summits 
of the internodes and bases of the branches in the inflorescence and short, very 
thick, papillose cilia along the lateral nerves of the second glume and sterile 
lemma, and somewhat spreading "spikes", and sterile lemmas with awns 0-10 
mm. long; synonyms include E. crusgalli subsp. muricata (Michx.) Shinners, var. 
muricata (Michx.) Shinners and var. microstachya (Wieg.) Shinners, and perhaps 
var. mitis (Pursh) Peterm. 

Var. zelayensis (H.B.K.) Hitchc, with non-papillate ascending cilia in the 
inflorescence or these absent, and short, thinner, not-so-markedly papillose cilia 
along the nerves of the second glume and sterile lemma, usually strictly ascending 
"spikes", and sterile lemma rarely short-awned; synonyms include E. crusgalli 
subsp. zelayensis (H.B.K.) Shinners and var. macera (Wieg.) Shinners. 

Japanese millet is planted in places and occasionally escapes; it is usually called 
E. crusgalli var. frumentacea (Link) W. Wight but is no doubt merely a cultivar 
of var. crusgalli. 

One specimen from near Brownsville, Cameron Co. in the Texas Rio Grande 
Valley, has staminiferous lower florets and therefore corresponds to E. paludigena 
Wieg., which is otherwise identical to, and is to be referred to, E. crusgalli var. 
crusgalli. 

3. Echinochloa cruspavonis (H.B.K.) Schult. 

Diffuse annual, the lower parts of the culms long-trailing in water and mud 
and rooting at the nodes, the lower internodes 4-12 mm. thick; sheaths smooth; 
ligule obsolete; panicles long, slender, conspicuously nodding; "spikes" ascending 
or appressed, 1-4 cm. long, lengthily overlapping, often with stiff bristlelike hairs; 
second glume and sterile lemma with bodies 3-4 mm. long and awns, the awn 
of the lemma 4-29 mm. long, the nerves with spinulose cilia but these not con- 
spicuously papillose. Panicum cruspavonis (H.B.K.) Nees, E. crusgalli var. crus- 
pavonis (H.B.K.) Nees. 

Marshy margins of streams and lakes, infrequent in s.e. Tex. and n. parts of 
Rio Grande Plains, rare in the Trans-Pecos, summer-fall; trop. areas of Afr. 
and Am., n. to Ala., La. and Tex.; also rare in Va. 

4. Echinochloa Walter! (Pursh) Heller. 

Mostly erect annual; culms 4-17 mm. thick basally; sheaths papillose-pilose 
or papillose-hispid at least part of the length or rarely wholly glabrous; ligule 
obsolete; panicles elongate, nodding; "spikes" 2-10 cm. long, ascending or spread- 
ing, lengthily overlapping, often with stiff bristlelike hairs; second glume and 
sterile lemma with bodies 3-4 mm. long and awns, the awns of the lemma 10-43 
mm. long, the nerves (especially the lateral) with conspicuously papillose-spinu- 
lose cilia. Panicum Walteri Pursh. 

329 




Fig. 166: Ecliinochloa colonum: a. culm, leaf sheath and ciliate leaf base, X 3; 
b, spikelet, X 12; c, floret, adaxial view, showing indurated pales, X 12; d, floret, 
abaxial view, showing indurated lemma, X 12; e, habit, showing decumbent stems root- 
ing at the nodes, X Y^. (From Mason, Fig. 62). 




Fig. 167: Echinochloa crusgalU: a, panicle, X %; b, leaf sheath and ciliate leaf 
base, X 3; c, habit, X %. (From Mason, Fig. 63). 



Margins of streams and irrigation ditches, swampy places, in shallow water 
of ponds and in brackish marshes, in Okla. (Murray and Kay cos.) and extreme 
n. edge of Tex. Rio Grande Plains, s. parts of n.-cen. Tex. and e. Tex., infrequent, 
summer; Wise, Va., S.C., Ark., La., Okla., Tex. and Coah. 

5. Echinochloa polystachya (H.B.K.) Hitchc. 

Long-creeping perennial, some of the lower internodes 3-6 mm. thick; nodes 
villous; sheaths smooth; ligule a row of stiff yellowish hairs (use lens); panicles 
slender and usually nodding; "spikes" 2-5 mm. long, strictly ascending and ap- 
pressed, the lower ones only slightly overlapping, often with stiflf bristlelike hairs; 
second glume and sterile lemma with bodies 4—5 mm. long and awns, the awn of 
the lemma 4-18 mm. long, the nerves (especially the lateral ones) with spinulose 
cilia but these not conspicuously pilose. Panicum polystachyum H.B.K. 

Infrequent in moist clay loam, in shallow water, swamps and ditches, coastal 
parts of Tex. Rio Grande Plains and s. part of s.e. Tex., Mar.-Nov.; warm-temp, 
and trop. parts of Am., n. to Cuba and Tex. 

55. Setaria Beauv. Bristle Grass. Millet 

Panicles with many nodes and short branches, each branch system exhibiting 
numerous reduced sterile branohlets which are seen as bristles subtending the 
spikelets; spikelets essentially sessile, each falling as a unit, 2-flowered. the lower 
floret staminate or completely reduced, the upper perfect; first glume much shorter 
than the spikelet, several-nerved, membranous; second glume nearly as long as 
the spikelet, several-nerved, membranous; lower ("sterile") lemma several-nerved, 
membranous, usually not quite as long as the fertile lemma; sterile palea nearly 
obsolete to well-developed and as long as the sterile lemma; fertile lemma indurate, 
strongly convex, the margins revolute and clasping the palea of the same texture, 
smooth or usually faintly to strongly transversely rugose. 

A genus of about 140 species in the warmer parts of the world; closely related 
to certain species of Panicum and probably best treated as a subgenus of that 
genus. 

1. Bristles 4 to 12 below each spikelet; panicles spiciform, not tapering nor inter- 
rupted (2) 

1. Bristles 1 to 3 below each spikelet; panicles tapering or if spiciform then 

usually interrupted in the lower part (3) 

2(1). Plants perennial, from hard knotty subrhizomatous bases; spikelets mostly 
1.2-1.6 mm. broad, elliptic 1. S. geniculata. 

2. Plants annual, from bases that are not hard knotty or subrhizomatous; spikelets 

mostly 1.5-1.9 mm. broad, turgid 2. 5. glauca. 

3(1). Bristles retrorsely scabrous 3. S. verticillata. 

3. Bristles antrorsely scabrous only 4. S. magna. 

1. Setaria geniculata (Lam.) Beauv. Fig. 168. 

Perennial from hard knotty subrhizomatous bases; aerial culms 2-10 dm. long, 
geniculate at the lower nodes, mostly erect; blades 3-8 mm. broad, mostly rather 
strictly erect; panicles 1-8 cm. long, cylindric. about 15 mm. thick, dense, a I -cm. 
transection including 13 to 25 spikelets; spikelets subtended by numerous stiflf 
bristles, mostly 2.5-3 mm. long. 1.2-1.6 mm. broad, elliptic to elliptic-ovate; lower 
(sterile) floret usually staminiferous with a well-developed palea. 

Most common in disturbed moist areas, in mud along streams, salt and fresh- 
water marshes, in mud and shallow water about ponds and lakes, in Okla. (Alfalfa. 
Pittsburg. Mayes and LeFlore cos.), throughout Tex.. N.M. (Hitchcock) and 
Ariz. (Santa Cruz Co.), spring-fall; in warmer parts of Am. n. to Calif., Ariz., 
N.M., Kan., la., W.Va. and Mass. 

332 










Fig. 168: Setaria geniculata: a, spikelet, showing fertile lemma and the few up- 
wardly barbed bristles on branchlet, X 12; b, floret, showing palea, X 12; c, spikelet, 
showing first glume and sterile lemma, X 12; d, rachilla, the bristles remaining and the 
spikelets having fallen off from the branchlets, X 6; e, leaf sheath, showing long-ciliate 
ligule and the sparsely set long hairs at base of the scabrous blade, X 6; f, habit, upper 
part, showing the slender linear panicles, X %; g, habit, lower part, showing the 
knotty branching rhizomes and the erect, ascending leaf blades, X %. (From Mason, 
Fig. 84). 



2. Setaria glauca (L.) Beauv. Yellow Foxtail. Fig. 169. 

Loosely-tufted annual; culms 2-10 dm. long, often geniculate and decumbent 
basally, ascending distally; blades 4-10 mm. broad, ascending; panicles 1-8 cm. 
long, cylindric, about 1 cm. thick, fairly dense, a 1-cm. transection near the 
middle including 11 to 20 spikelets; each spikelet subtended by numerous bristles, 
mostly 2.5-3.2 mm. long, 1.4-2.1 mm. broad, rotundly ovate, turgid; lower (sterile) 
floret usually staminiferous with a well-developed palea. S. lutescens (Weig.) 
F. T. Hubb. 

In wet soil on edge of ponds, lakes and streams, in wet meadows, ditches 
and on gravel bars along streams, in Okla. (Waterfall), nearly throughout Tex. 
but absent from Rio Grande Plains and Plains Country, rare in the Trans-Pecos, 
in N. M. (Sierra Co.) and Ariz. (Apache, Coconino, Gila, Maricopa, Cochise, 
Yavapai, Pima and Yuma cos.), summer-fall; nearly throughout the temp, and 
trop. areas of the world, introd. from Eur. 

3. Setaria verticillata (L.) Beauv. Fig. 170. 

Plants annual; culms to 1 m. long, simple or more often much-branched at 
base, geniculately spreading and rooting at nodes; leaf blades flat, thin, scabrous 
and sparingly pilose, 5-10 mm. wide, 10-20 cm. long; panicle erect, not rigid, 
slightly tapered, sometimes interrupted at base, 5-15 cm. long, 7-15 mm. thick, 
bristles 1 below each spikelet, retrorsely scabrous and 1 to 3 times as long as the 
spikelet; spikelet 2 mm. long; fruit finely rugose. 

Along ditch banks and in muddy or waste places, in Okla. (Muskogee Co.) and 
Ariz. (Coconino, Mohave, Cochise and Pima cos.); Mass. to N.D., s. to Ala., Mo. 
and Okla., w. to Ariz, and Calif., introd. from Eur. 

4. Setaria magna Griseb. 

Robust annual; culms 1-4 m. tall, 5-20 mm. thick basally, prop-rooting from 
the lower nodes but erect and simple; panicles 25-60 cm. long, 2-3 cm. thick, 
dense (the axis mostly hidden); spikelets very numerous, about 2 mm. long; fertile 
lemma smooth, shiny. 

In marshes, wet places, moist ditches, bayous, etc., s.e. Tex., summer-fall; 
Coastal States, N.J. to Tex.; W.I., Yuc, C. R. 

56. Cenchrus L. 

About 160 species in warmer parts of the world. Individuals of this genus 
are exceedingly abundant, especially so in disturbed, sandy, non-forested areas 
and at elevations below 4.000 feet. Several species have been introduced, including 
Pearl Millet and Napier Grass. Some authors segregate the genus into two genera 
on trivial technical grounds. The spiny burs cause pain and sometimes infection 
when they penetrate the skin, and they are noxious to animals when mixed with 
hay. 

1. Cenchrus myosuroides H.B.K. 

Perennial from hard knotty subrhizomatous bases; culms 6-20 dm. long, erect; 
panicle (6-) 10-23 cm. long, 6-12 mm. thick, interrupted at the very base, other- 
wise rather dense, a 1-cm. transection near the middle containing 7 to 10 burs; 
internodes of axis about 1-1.5 mm. long; burs about 3 mm. thick basally, the 
bristles numerous (about 35 to 60 per bur), united only basally in the short cup 
which does not equal the spikelets, greatly unequal (outer ones shortest), spreading 
(outer) or ascending (inner ones), the inner ones stiff, none plumose. 

In ditches and near creeks or springs, infrequent in the Tex. Rio Grande Plains, 
rare in the Trans-Pecos, summer-fall; Col., Ecu., Bol., Chile, Parag., Arg. and 
extreme s. Braz.; also W.I. n. to Fla. Keys; Mex.; Tex. 

334 




Fig. 169: Setaria glauca: a, spikelet, showing first glume and sterile lemma, X 10; 
b, spikelet, showing fertile lemma and the upwardly barbed slender bristles on branch- 
let, X 10; c, floret, showing palea, X 10; d, leaf sheath and ciliate ligule, X 6; e, habit, 
upper part of culm, showing spikelike panicle, X %; f, habit, lower part, showing the 
leaf blades with villous base above sheath, X %. (From Mason, Fig. 83). 



57. Erianthus Michx. Plumegrass 

Perennials, 1-3 m. tall, forming robust clumps; leaves elongate; ligules narrow, 
usually hippocrepiform; panicle 1-9 dm. long, terminal, often pyramidal to clavate 
or even slender; spikelets in pairs, one of each pair sessile, one pedicelled, both 
perfect, usually 4-6 mm. long (not including awn), typically membranous to 
coriaceous, usually dorsally villous with long hairs; sterile lemma hyaline, shorter, 
with usually 1 median nerve; fertile lemma narrow, ovate-lanceolate, hyaline, with 
usually a prominent straight or twisted exserted awn 4-20 mm. long; palea (if 
present) hyaline. 

A genus of 28 species of southeast Asia to southeast Europe, Madagascar, and 
the warmer parts of America. 

1. Culm appressed-hairy below the panicle (2) 
1. Culm glabrous below the panicle (3) 

2(1). Awn straight or slightly flexuous 4. E. giganteus. 

1. Awn loosely twisted 3. E. alopecuroides. 

3(1). Hairs subtending the spikelet few and short or absent; panicle nearly com- 
pletely glabrous; awn straight 1. E. strictus. 

3. Hairs subtending the spikelet as long as or longer than the spikelet; panicle 
very hairy; awn 2 cm. long, coiled 2. E. contortiis. 

1. Erianthus strictus Baldw. Narrow plumegrass. 

Perennial; culms 1-2 m. tall, relatively slender, glabrous; nodes sometimes 
hirsute with stiflf erect deciduous hairs; internode below the panicle glabrous; 
foliage glabrous; lower sheaths narrow and crowded; blades mostly 4-12 mm. 
broad; panicle 2-4 dm. (rarely 8 dm.) long, strict (about 1-2 cm. thick), the 
branches closely appressed; spikelets brown, about 8-1 1 mm. long (not including 
awn), scabrous, nearly naked to sparsely short-hairy at base; awn straight, 15-20 
mm. long; rachis joint and pedicel scabrous. 

Rare in moist sandy places, marshes and swamps, in Okla. {Waterfall), e. and 
s.e. Tex., fall; Va. to Fla. and Tex., n. to Tenn. and Mo. 

2. Erianthus contortus Baldw. Bent-awn plumegrass. 

Perennial; culms 1-2 m. tall, glabrous or sometimes sparsely appressed-pilose 
below the panicle; nodes glabrous or pubescent with erect deciduous hairs; inter- 
nodes below the panicle glabrous; sheaths sparsely pilose at summit or glabrous; 
blades 10-15 mm. broad, scabrous; panicle 15-30 cm. long, narrow, the branches 
ascending but not closely appressed; spikelets 6-8 mm. (excluding awn) long, 
brownish, the basal hairs nearly or about as long as the spikelet; awn about 2 cm. 
long, spirally coiled at base; rachis joint and pedicel villous. 

Rare in moist sandy places, especially wet pinelands, in Okla. {Waterfall), 
e. and s.e. Tex., fall; Md. to Fla. and Tex., n. to Tenn. and Okla. 

3. Erianthus alopecuroides (L.) Ell. Silver plumegrass. 

Perennial; culms robust, 15-30 dm. tall, appressed-villous below the panicle 
and usually on the nodes; sheaths pilose at the summit; blades 12-20 mm. wide, 
scabrous, pilose on upper surface toward base; panicle 2-3 dm. long, silvery to 
tawny or purplish: spikelets 5-6 mm. long, pale, sparsely villous, shorter than 
the copious basal hairs; awn 10-15 mm. !ong, flat, loosely twisted; rachis joint 
and pedicel long-villous. E. divaricatus Hitchc. 

Infrequent in sandy woodlands, usually near water or in seepage, in Okla. 
{Waterfall), c. and s.e. Tex., fall: N.J. to ill., s. Mo. and Okla., s. to Gulf States. 

336 




Fig. 170: Setaria verticillata: a, spikelet, showing short first glumes and the single 
downwardly barbed bristles on branchlets, X 16; b, floret, showing lemma, X 16; c, 
auricled leaf sheath and ciliate ligule, X 4; d, panicle, X if,; e, floret, showing palea, 
X 16; f, habit, upper part, showing panicles, X V-,; g, habit, lower part, showing the 
lax arching leaf blades and roots at the nodes, X %. (From Mason, Fig. 85). 



4. Erianthus giganteus (Walt.) Muhl. Sugarcane plumegrass. Fig. 171. 

Perennial; culms 1-3 m. tall, appressed-villous below the panicle, the nodes 
appressed-hispid, the hairs deciduous; sheaths and blades from nearly glabrous to 
shaggy appressed-villous; blades 4-15 mm. broad; panicle 10-15 (-40) cm. long, 
oblong or ovoid, tawny to purplish; spikelets 5-6 (-7) mm. long, sparsely long- 
villous on the upper part, shorter than the copious basal hairs; awn 10-25 mm. 
long, terete, straight or rarely slightly flexuous; rachis joint and pedicel long- 
pilose. E. saccharoides Michx., E. Tracyi Nash, E. laxus Nash, £. compactus Nash. 

Infrequent in sandy soil, usually near moisture, often in marshes or seepage 
areas, in Okla. {Waterfall), e. and s.e. Tex., fall; N. Y. to Tex.; Cuba; probably 
elsewhere in trop. Am. 

58. Andropogon L. Bluestem 

In the present strict sense this is a genus of some few dozens of species of the 
temperate and subtropical areas of the Old World and New World. 

1. Andropogon glomeratus (Walt.) B. S. P. Bushy beardgrass. 

Perennial; culms erect, 5-15 dm. tall, compressed, with broad keeled overlapping 
lower sheaths, the flat tufts often forming dense usually glaucous clumps, the 
culms from freely to bushy-branching toward the summit; sheaths occasionally 
villous; blades elongate, 3-8 mm. wide; inflorescence dense, feathery, from flabel- 
late to oblong, the paired racemes 1-3 cm. long, about equaling the slightly 
dilated spathes, the enclosed peduncle and ultimate branchlets long-villous, the 
peduncle at least 5 mm. long or often longer; rachis very slender, flexuous, long- 
villous; sessile spikelets 3-4 mm. long, the awn straight, 10-15 mm. long; sterile 
spikelet reduced to a subulate glume or wanting, the slender pedicel long-villous. 
A. virginicus var. abbreviatus (Hack.) Fern. & Grisc. 

Frequent in moist areas, in marshes and swamps, on wet springy slopes and 
in seepage areas, on edge of water about springs and ponds, in Okla. (Haskell 
Co.), e. half of Tex., rare westw., in N. M. (Eddy Co.) and Ariz. (Coconino, 
Mohave, Maricopa, Pinal and Santa Cruz cos.), late summer-fall; s.e. U.S. n. to 
N.E., Ky., Okla.; also N.M., Ariz., Nev., Calif., Mex., W.I. and C.A. 

59. Sorghum Moench 

A large genus centered in the Near East; at least 2 species are cultivated and 
escaped in Texas. 

1. Sorghum halepense (L.) Pers. Johnson grass. Fig. 172. 

Robust perennial; culms 5-15 dm. tall, from extensively creeping scaly rhizomes; 
blades mostly less than 2 cm. wide; panicle open, terminal, of several to numerous 
racemes, 15-50 cm. long; spikelets tardily disarticulating just below each sessile 
spikelet; fertile sessile spikelet 4.5-5.5 mm. long, ovate, appressed-silky, the 
readily deciduous awn 10-15 mm. long, geniculate, twisted below; sterile pedi- 
cellate spikelet 5-7 mm. long, lanceolate. 

Open ground, fields and waste places, along irrigation ditches and in wet depres- 
sions, Mass. to la. and Kan., s. to Fla. and Tex., w. to s. Calif.; nat. of the Medit. 
region but in the trop. and warmer regions of both hemispheres. 

Cultivated for forage, but because of the diflficulty of eradication it becomes a 
troublesome weed. 

60. Manisuris L. Joint-tail 

Perennial moderately tall plants; racemes nearly cylindrical, their rachises gla- 
brous or nearly so and quite thick, the base of each internode on one side sculp- 
tured with a niche into which the spikelets fit closely; pedicellate spikelets reduced, 

338 




Fig. 171: Erianthus giganteus: plant, X i/^; spikelet with pedicel and rachis joint, 
X 5. (From Hitchcock & Chase). 









Fig. 172: Sorfihion halepense: Plant, X Vr, two views of terminal raceme, X 5. 
(From Hitchcock & Chase). 



often rudimentary. 

A small genus of the warmer parts of the world. 

1. Racemes flattened, tardily disarticulating; first glume of sessile spikelet smooth 
1. M. altissima. 

I. Racemes nearly cylindric, readily disarticulating at maturity; first glume of 
sessile spikelet marked with pits or wrinkles 2. M. rugosa. 

1. Manisuris altissima (Poir.) Hitchc. 

Perennial; culms ascending from a long creeping base, compressed and 2-edged, 
4-8 dm. long, freely branching toward the ends; blades flat, 3-8 mm. wide; flower- 
ing branches often short and fascicled; racemes 3-5 cm. or sometimes 1 dm. long, 
compressed; pedicel free or partly adnate to the rachis joint; sessile spikelet 5-7 
mm. long, the keels of the first glume very narrowly winged toward the apex; 
pedicellate spikelet 5-6 mm. long, acute. 

Rare in coastals. Tex., where repeatedly introd. in ponds, ditches and on edge 
of water in the Rio Grande, spring-fall; warmer parts of the world, introd. in Am. 

2. Manisuris rugosa (Nutt.) O. Ktze. 

Perennial; culms mostly rather stout, 7-12 dm. tall, freely branching; sheaths 
compressed-keeled; blades commonly folded, 3-8 mm. wide; flowering branches 
often numerous; racemes 4—8 cm. long, partly included in brownish sheaths; rachis 
joint and pedicel contracted in the middle; sessile spikelet 3.5-5 mm. long, the 
first glume strongly and irregularly transversely ridged, the keels narrowly winged 
toward the summit. 

Infrequent in open woodlands on low often moist or wet sandy loam, in wet 
savannahs and wettish pine woods, in e. and s.e. Tex., summer-fall; Coastal 
States, Va. to Tex.; Ark. 

61. Tripsacum L. 

A small American genus of which we have one species. 
1. Tripsacum dactyloides (L.) L. Eastern gamagrass. Fig. 173. 

Very robust perennial, usually 15-30 dm. tall, often with rhizomes, glabrous 
throughout; blades elongate, 1-2 cm. broad, flat; inflorescence 15-25 cm. long, 
terminal, subdigitate group of a few androgynous spikelike racemes, each with a 
few lower solitary pistillate fertile spikelets at the base and many paired staminate 
spikelets above; pistillate spikelets 7-10 mm. long, occasionally subtended by a 
rudimentary pedicel, arranged on opposite sides at each joint of the thick hard 
articulate lower part of the rachis, sunken in niches of the sculptured rachis, con- 
sisting of one perfect floret and a sterile lemma; first glume coriaceous, nearly 
infolding the spikelet, fitting into and closing the hollow of the rachis; second 
glume similar to the first but smaller, infolding the remainder of the spikelet; 
sterile and fertile lemmas and palea very thin and hyaline; staminate spikelets 
7-1 1 mm. long, paired and 2-flowered; glumes firm, acute; lemma and palea 
hyaline. Incl. var. occidentale Cutler & Anders. 

In marsh-meadows, wet grasslands, seepage areas, in wet mud along streams and 
about ponds, in Okla. (LeFlore Co.), frequent in scattered parts of Tex. but more 
common in the e. half, very rare in the Plains Country, summer-fall; W.I.; e. U.S., 
Coah., N.L., Tarn., S.L.P. 

Fam. 25. Cyperaceae Juss. Sedge Family 

Herbs with tristichous leaves and often triangular stems; blades grasslike, often 
long and linear or gradually tapered; inflorescences diverse; florets often borne 
grouped into spikelets, each floret subtended by a single abaxial scale (apparently 

341 




Fig. 173: Tripsacum dactyloides: plant, X Vl-; pistillate spikelets with rachis joint 
and pair of staminate spikelets with rachis joint, X 5. (From Hitchcock & Chase). 



2 scales in Hemicarpha\ pistillate flower surrounded by a sac in Carex); perianth 
either of bristles or plumes or more elaborate structures or absent; fruit an achene. 
About 4000 species in 90 genera of world-wide distribution. 

1. The unit of the infructescence (i.e., the object bearing one seed and which 
falls from the plant at maturity) comprising not only an achene 
and usually a portion of the style but also a thin bag surrounding 
those structures; monoecious or dioecious 16. Carex 

1. The unit of the infructescence merely an achene with or without attached 

stylar or other floral tissue, but never surrounded by a sac (2) 

2(1). Perianth of 3 stalked scalelike or paddlelike structures, often thickened 
at maturity, with or without 3 bristles in addition 4. Fuirena 

2. Perianth of bristles or plumose structures or absent (3) 

3(2). All or virtually all florets of each spikelet perfect (4) 

3. In each spikelet either the florets all pistillate or all staminate or merely 

some of them strictly staminate (12) 

4(3). Each achene subtended by 2 scales, the lower scale easily visible, the adaxial 
one hyaline, very inconspicuous and often split or torn by the 
growing achene or adhering to it 8. Hemicarpha 

4. Each achene subtended only by one abaxial scale (5) 

5(4). Culms naked, the sheath solitary on the extreme base of the culms and 
entirely bladeless 5. Eleocharis 

5. Culms not so naked, if some of the sheaths bladeless then each culm with 

several of them (6) 

6(5). Scales of spikelets distichous and perianth bristles present; base of style 
not much swollen but almost the entire style below the fork per- 
sistent on the achene 1. Didichium 

6. Scales of spikelet distichous or spirally imbricate and perianth bristles present 

or absent, but if scales distichous then bristles absent; base of style 
swollen or not, persistent or deciduous (7) 

7(6). Swollen style base persistent on the achene as a tubercle of a color and 
texture distinct from those of the achenial body (8) 

7. Style swollen or not but not persistent on the achene (9) 

8(7). Style 3-branched; achene trigonous 6. Bulhostylis 

8. Style 2-branched; achene biconvex 14. Psilocarya 

9(7). Scales of spikelets distichous on the spikelet axis (this obscure in C. sesqui- 
flonis, C. tenuifolius and C. brevifolius) 9. Cyperus 

9. Scales of spikelets spirally arranged (10) 

10(9). Style base swollen 7. Fimbristylis 

10. Style terete, slender, not dilated at the base (11) 

11(10). Perianth of I to 8 bristles or wanting 2. Scirpus 

11. Perianth of numerous elongate silky or woolly bristles 3. Eriophorum 

12(3). Inflorescence bracts basally white, distally green 12. Dichromena 

12. Inflorescence bracts essentially unicolored, green (13) 

13(12). Scales of spikelets visibly distichous; spikelets agglomerated into a tight 
head 1 1. Schoeniis 

13. Scales of spikelets spirally disposed (this obscure in Scleria) or at least not 

definitely distichous (14) 

14(13). Style base enlarged and persistent as a tubercle of a color and texture 
distinct from those of the achenial body; perianth bristles or plumes 
usually present 13. Rhynchospora 

343 



14. Style base not persistent; perianth absent (15) 

15(14). Achene often bony, pearly or crustaceous, supported on a disk or 
appearing sculptured basally; pistillate flowers solitary and borne 
in separate spikelets 15. Scleria 

15. Achene otherwise; spikelets all alike and borne in very large inflorescences 

10. Cladium 

1. Dulichium Pers. 

The genus comprises only one species; confined to North America. 
1. Dulichium arundinaceum (L.) Britt. Three-way sedge. Fig. 174. 

Perennial with creeping rhizomes 2-3 mm. thick and with internodes 2-5 cm. 
long; culms simple, solitary from the nodes of the rhizomes, 2-10 dm. long, 2-5 
mm. thick, erect, with short internodes; lowest leaves with nearly bladeless sheaths, 
the upper with short stiff pointed ascending blades 2-10 cm. long, the upper 5 to 
20 leaves functioning as bracts, each subtending a peduncled spike; peduncle of 
spike only slightly longer than the bract sheath; spike 2-6 cm. long, 15-50 mm. 
thick, of 6 to 15 ascending to eventually spreading spikelets; spikelets of 5 to 10 
distichous scales, the axis with each internode thickened and concave (niched) on 
the fertile side and with 2 narrow vertical wings at the edges of the niche; perianth 
bristles 6 to 9, coarse, longer than the achene, retrorsely serrate; style branches 2; 
achene flattened, beaked with the long persistent style. 

Infrequent or rare in boggy places, edge of streams and swamps, e. Tex. 
(Leon, Robertson, Cass, Madison, Henderson and Wood cos.), fall; wet places 
and in shallow water over much of the lowlands of U.S., n. to Nfld., Que., Ont. 
and B.C., s. to the Gulf States and Calif. 

2. Scirpus L. Bulrush 

Annual or perennial herbs, usually aquatic; leaves either well-developed or 
the blades much-reduced in some species; inflorescences very variable; scales of 
spikelets spirally imbricate; each flower with only a single subtending scale; 
bristles present or rarely absent; styles 2- or 3-branched; achenes plano-convex, 
biconvex or trigonous, usually apiculate but the apex of the same texture and 
color as the rest of the achene (not differentiated as a "tubercle"); style completely 
deciduous. 

About 300 species, cosmopolitan. 

1. Bracts leaflike, none appearing as a continuation of the culm (2) 

1. Primary bract appearing as a continuation of the culm and similar to it in 

texture, color and usually in transectional outline (10) 

2(1). Spikelets in dense spherical or prolate heads 1-2 cm. thick 

1.5. cuhensis. 

2. Spikelets either solitary on their peduncles or in small fascicles or glomerules, 

never in dense heads (3) 

3(2). Achene 3-5 mm. long (4) 

3. Achene about 1 mm. long (5) 

4(3). Achene dull gray-brown, 4-5 mm. long; bristles 6, stiff, retrorsely barbed 
2. S. ftuviatilis. 

4. Achene dark-brown to black, 3>-^ mm. long; bristles 2 to 6, fragile or 

deciduous 3. S. maritiinus. 

5(3). Bristles very long and far-surpassing the scales, conspicuous in fruit 

4. S. cyperinus. 

5. Bristles mostly shorter than the scales or if longer then never exserted from 

the spikelet (6) 

344 




Fig. 174: Dulichium arundinaceum: a, inflorescence, X ^-y, b, base of stems and 
rhizomes, X y^; c, several spikelets, X 3; d, flower with scales removed, X 3. (V. F.). 



6(5). Bristles straight or slightly curved or none (7) 
6. Bristles strongly curved (9) 

7(6). Inflorescence usually 2 or more times compound, the clusters loose; achene 
lenticular or plano-convex; style bifid 5. S. microcarpus. 

I. Inflorescence usually only once compound, the clusters of spikelets commonly 

dense; achene obtusely trigonous; style trifid (8). 

8(7). Rhizomatous; bracts as long as or exceeding the inflorescence; each spike- 
let with 20 to 40 florets 6. 5. atrovirens. 

8. Not distinctly rhizomatous; bracts shorter than the inflorescence; each spikelet 

with 70 to 200 florets 7. S. georgianus. 

9(6). Principal leaves 3-8 mm. wide; sessile spikelets usually glomerate; curling 
bristles mostly much longer than the achene 8. S. Uneatus. 

9. Principal leaves 8-12 mm. wide, sessile spikelets usually solitary; curling 

bristles rarely exceeding tne achene 9. S. fontinalis. 

10(1). Achene 0.8-0.9 mm. long 10. S. molestus. 

10. Achene 1.3-4 mm. long (11) 

11(10). Achene 1.3-1.5 mm. long; culms 0.3-1.8 mm. thick; tufted annuals (12) 

II. Achene 1.5-4 mm. long; culms usually thicker; rhizomatous perennials (13) 

12(11). Achene with vertical rows of minute pits 11. 5. koilolepis. 

12. Achene with horizontal ridges 12. S. supinus. 

13(11). Culms 3-20 dm. long, often sharply triquetrous, 2-8 mm. thick, often 
arcuate (14) 

13. Culms 10-30 dm. long, either terete or only obscurely trigonous, 8-23 mm. 

thick near the base, 2-4 mm. thick just beneath the inflorescence, 
usually rigidly erect (15) 

14(13). Achene 2.5-3 mm. long; lower scales or the spikelets often much longer 
than the rest and with strong venation, bracteolelike; inflorescence 

a solitary spikelet or glomerule of 2 to 4 spikelets 

13. 5. americanus. 

14. Achene 1.8-2.6 mm. long; lower scales of the spikelets not differentiated; 

inflorescence a dense glomerule of 5 to 15 spikelets 

14. S. Olneyi. 

15(13). Achene bristles 2 to 4 (16) 

15. Achene bristles 4 to 6 (17) 

16(15). Sheaths (near base of culm) at margins rather regularly retrorsely 

fimbriate-filiferous; bristles ciliate or plumose, not barbed 

15. S. californicus. 

16. Sheaths smooth or merely lacerate; bristles fragile, barbellate or smooth 

16. 5. heterochaetus. 

17(15). Culm obscurely trigonous or flattened; at least the upper sheath with 

a well-developed blade; achene usually more than 3 mm. long 

17. S. etuherculatiis. 

17. Culm terete; sheaths without blades or a much-reduced blade only; achene 

less than 3 mm. long (18) 

18(17). Scales about 5 mm. long, thin-membranous, pale-brown and with con- 
spicuous elongate reddish glutinous spots (seen under a lens), the 
distal margin lacerate; achene 1.8-2.9 mm. long 18. S. aciitus. 

18. Scale 3-4 mm. long, firm-membranous, dark-brown, nearly smooth (occa- 

sionally with a few reddish gummy spots near the midveins), the 
distal margin nearly smooth to slightly lacerate; achene 1.5-2.2 
mm. long 19. S. validus. 

346 




Fig. 175: Scirpus fluviatilis: a-d, achenes, showing variation in shape (cross section), 
X 6; e, flower, style slender and trifid, the bristles unequal in length, X 3; f and g, 
awned scales, X 4; h, achene, the subtending bristles unequal in length, X 4; i, spikelet, 
X ly-,; j, rhizome, tubers and sharply triangular culms, X %; k, inflorescence with 
nearly sessile rays and longer primary rays, X %; 1, habit, showing rhizomes, tubers, 
sheathing culm leaves and umbellate inflorescence with the involucral leaves unequal 
in length, X %• (From Mason, Fig. 148). 




Fig. 176: Scirpus maritimus var. poliidosiis: a, inflorescence, X ^4; b, lower part of 
stems and rhizomes, X V2; c, spikelet, X 3; d, scales, X 5; e, achene, X 5. (V. F.). 



1. Sclrpus cubensis Poepp. & Kunth. 

Rhizomatous perennial; rhizome 1-5 mm. thick; aerial culms solitary at the 
nodes of the rhizome, to 1 m. tall, sharply trigonous, smooth; leaves all basal 
with blades to 15 mm. broad; inflorescence involucrate, umbel-like; bracts 2 to 
5, leaflike, spreading, unequal, often much-elongate, far-surpassing the umbel; 
branches of umbel very unequal (1 head usually quite sessile), usually 1-3 cm. 
long; each branch terminated by a dense spherical or somewhat prolate head 1-2 
cm. thick; each head of many spikelets; scales about 3 mm. long, reddish, spread- 
ing, tapered to the acute reflexed tip; bristles absent; style bifid; achene about 3 
mm. long, lenticular, apiculate. 

Very rare, known only from Eagle Nest Lake, Brazoria Co., Tex. where collected 
once in 1958, summer-fall; warmer parts of Am., n. to Gulf States; also Afr. 

2. Scirpus fluviatilis (Torr.) Gray. River bulrush. Fig. 175. 

Perennial sedge with horizontal rhizomes forming tubers; culms stout, sharply 
triangular, erect, 1-1.5 m. tall; leaves 8-16 mm. wide; involucral leaves 3 to 5, 
unequal in length, to 20 cm. long; inflorescence umbellate, rays 5 to 12, elongate, 
recurved-spreading, up to 12 cm. long; spikelets acute, 1.6-4 cm. long; bristles 6, 
retrorsely barbed, stiff, unequal in length, nearly as long as the achene; anthers 
2.5-4.5 mm. long; style trifid; achene usually sharply triangular, angled on back, 
dull gray-brown, 4-5 mm. long. 

In shallow water and wet mud of sloughs, swamps, lakes, and along rivers and 
streams, in N. M. (Fernald); Que. to Sask. and Wash., s. to Va., Ind., 111., Mo., 
Kan.. N.M. and Calif. 

3. Scirpus maritimus L. Salt-marsh bulrush. 

Rhizomatous perennial; rhizome several mm. thick, extensive; culms tufted 
along the rhizome, often with tuberlike enlargements basally, 5-20 mm. thick 
above the tuber, 30-100 cm. long, erect, triquetrous; leaves several, well- 
developed; bracts several, flat, leaflike, ascending or usually spreading; inflores- 
cence of 3 to 15 ovoid to ovoid-cylindric erect or ascending spikelets, either all 
sessile or some variously sessile and others peduncled, quite variable; scales 6-10 
mm. long, almost as broad, apically mostly refuse and the midnerve prolonged 
into a point 1-3 mm. long; achenes obovate-apiculate, 3^ mm. long, about 2 mm. 
broad, in transection biconvex or one of the sides more convex or bifaceted than 
the other, ripening to a dark-brown. The species is nearly world-wide. 

We have 2 varieties: 

Var. macrostachyus Michx. Scales firm, maturing to a dark-brown; styles usually 
3-branched. S. robustus Pursh. 

Coastal marshes, s.e. Tex. and Rio Grande Plains, spring-summer-fall. 

Var. paludosus (A. Nels.) Koyama. Fig. 176. Scales thin, translucent, whitish 
to pallid-buff; styles uniformly 2-branched. S. paludosus A. Nels. 

Marshes, salt flats and in mud about ponds and lakes, and along streams, in 
Okla. (Ottawa. San luan, Colfax, Washita, Blaine and Alfalfa cos.), n.-cen. and 
Trans-Pecos Tex., the Plains Country, Edwards Plateau and Rio Grande Plains, 
N. M. (Dona Ana, San Juan. Chaves, Colfax, Quay and Eddy cos.) and Ariz. 
(Apache, Navajo, Coconino and Mohave to Pinal and Maricopa cos.) 

4. Scirpus cyperinus (L.) Kunth var. rubricosus (Fern.) Gilly. Fig. 177. 

Perennial probably from short thick rhizomes; culms 8-20 dm. long. 6-13 
mm. thick basally. 3-4 mm. thick apically where obscurely trigonous; leaves 
numerous; bracts several, leaflike, basally brownish or reddish-brown, ascending, 
the lowest one about as long as or slightly surpassing the inflorescence, the rest 
much shorter; inflorescence a dense decompound panicle (some of the longer 
primary branches 5-11 cm. long), somewhat droopy, of 200 to 500 spikelets. 

349 




Fig. 177: Siirpus cvpcriniis var. ruhricosus: a, habit, X '/a; b, scale, X 15; c, achene, 
about X 15. (Courtesy of R. K. Godfrey). 




Fig. 178: Scirpus microcarpus: a, achene and retrorsely barbed subtending bristles, 
X 12; b, achene (cross section), X 12; c, primary ray of umbel, X %; d, habit, show- 
ing the spreading leaf blades and their basal sheaths, the culm cut off, X l^; e, upper 
part of culm, with entire leaf sheaths and compound inflorescence, the involucral leaves 
extending beyond the inflorescence, X Vr,; f, spikelet, X 8; g, young leaf sheath, X 2; 
h, ovate acute scale with prominent midrib, X 16; i, flower, the style 2-cleft, X 16. 
(From Mason, Fig. 146). 



most of them on slender peduncles 4-10 mm. long, not in glomerules; spikelets 
ovoid to ellipsoid, brown, 3-5 mm. long, of 40 to 100 flowers; scales elliptic, 
1.5-2 mm. long, brown, acute; bristles several, very long, brown, far-surpassing 
the scales; achenes about 1 mm. long, oblong-apiculate, whitish, flattened-triangular 
(the abaxial angle blunt, the inner 2 sharp). 5. rubricosm Fern. 

Wet or boggy places, in water and muddy places, in Okla. (Waterfall) and e. 
Tex., summer; the var. cyperinus is widespread in e. U.S. and Can.; the var. 
rubricosus is found mostly in s.e. U.S. but occurs n. to Mich, and N.E. 

5. Scirpus microcarpus Presl. Fig. 178. 

Perennial with stout rhizomes; culms stout, erect, leafy, subterete, 7-17 dm. 
tall; leaves flat, broad, 1-2 cm. wide, margins scabrous, the blades acuminate, 
often overtopping the stem; involucral leaves 2 to 5, the longer ones usually ex- 
tending beyond the heads; inflorescence a loose spreading compound umbel, the 
primary rays to 10 cm. long; scales green to brown, acute, ovate, with a promi- 
nent midrib, not awned; bristles 4, downwardly barbed, somewhat longer than the 
achene; stamens 2; style 2-cleft; achene whitish, ovate, lenticular, with an obscure 
dorsal crest, mucronate, 1 mm. long. 

Along boggy streams, about springs and in mud at edge of stream, in N. M. 
(Catron, Colfax, Taos and Rio Arriba cos.) and Ariz. (Apache, Navajo, Coconino, 
Yavapai, Gila, Cochise and Pima cos.); Alas, to N.M., Ariz, and Calif. 

6. Scirpus atrovirens Willd. Fig. 179. 

Rhizomatous perennial; rhizome 2-6 mm. thick; culms 5-8 mm. thick basally, 
8-15 dm. long, erect, somewhat trigonous in the upper portion, leafy; bracts 
several, well-developed, leaflike, ascending or spreading, as long as or exceeding 
the inflorescence; inflorescence complicatedly decompound, of 100 to 250 (to 500) 
spikelets in glomerules which in turn are disposed in dense compound panicles, 
some of the primary branches that bear the panicles 5-14 cm. long; spikelets ovoid 
to narrowly ovoid, dark-brown to fuscous, of 20 to 40 flowers; bristles almost as 
long as the achene; scales 1.5-3 mm. long, ovate, acute, with a strong midrib; 
achene oblong, about 1 mm. long, in transection flattened-trigonous (the abaxial 
angle blunt, the others sharp). 

Most of the U.S. (except Pac. States), in and along streams and in wet 
meadows, about lakes and in sloughs. 

We have 2 varieties: 

Var. atrovirens. Scales with a minute mucro only. Rare in moist loam, e. 
Tex. (Angelina Co.), summer; otherwise in e. U.S. and e. Can., one station in 
Ariz. 

Var. pallidas Britt. Scales with a strong mucro or very short awn. 5. pallidus 
(Britt.) Fern. Rare in Tex. Plains Country (Panhandle), Okla. (Osage, Adair, 
Caddo and Woodward cos.), N. M. (Catron, Union, Colfax, Otero and San 
Miguel COS.) and Ariz. (Apache and Navajo cos.), summer; in cen. and w. U.S. 

7. Scirpus georgianus Harper. 

Tufted perennial from thick ascending ligneous caudexes but not distinctly 
rhizomatous; culms 5-15 dm. long, erect (some very shortly decumbent basally), 
3-6 mm. thick just above the caudex, obscurely trigonous above, leafy; bracts 
several, leaflike but reduced in size, ascending, shorter than the inflorescence; in- 
florescence a decompound often droopy panicle, some of the longer branches 3-7 
cm. long, the 50 to 120 spikelets not in glomerules but most of them on pedicels 
2-8 mm. long; spikelets ovoid to usually cylindric, of 70 to 150 (to 200) flowers 
at maturity; scales ovate, about 2 mm. long, acute, brown with very strongly pro- 
nounced green or bufly midnerve; bristles several, about twice as long as the 
achenes or as long as the scales but mostly crumpled and entangled and never 

352 




Fig. 179: a-d, Scirpus atrovirens: a, basal part of plant, X Y-y, b, upper part of plant, 
X V2; c, scale, X 10; d, achene, X 10. e-h, Scirpus Uneatus: e, basal part of plant, X V-y, 
f, inflorescence X 1/2; g, scale, X 10; h, achene, X 10. (V. F.). 



exserted from the spikelet: achene oblong, about 1 mm. long, in transection 
flattened-trigonous (the abaxial angle blunt, the others sharp). S. atrovirens var. 
georgianus (Harper) Fern. 

In bogs and wet mud along streams and about ponds and lakes, infrequent in 
n.-cen. Tex., rare in e. Tex., spring; P.E.I, s. to Ga. and w. to Neb. and Tex. 

8. Scirpus lineatus Michx. Fig. 179. 

Culms strongly ascending, firm, remotely 5- to 10-leaved, with long internodes; 
leaves 3-8 (-10) mm. wide, pale-green, firm; involucre and involucels pale-brown 
at base; umbels terminal and sometimes axillary, loose. 5-20 cm. high, subsecund, 
the terminal with a 1- to 3-leaved involucre much shorter than the long slender 
nodding-tipped rays; spikelets oblong, becoming cylindrical, 5-10 mm. long. 2-3.5 
mm. thick, the lateral ones of each group on smooth pedicels; scales pale-brown 
to rufescent, ovate, sharply and slenderly green-keeled, the sharp tips ascend- 
ing; achene obscurely 3-angled, narrowly ellipsoid to fusiform, long-beaked, papil- 
late; bristles curling, mostly longer than achene. 

Meadows, swales, edge of water of lakes and ponds, and in low wettish thickets, 
in Okla. (Murray, Love, Adair, Stephens, Choctaw, Johnston and Alfalfa cos.) 
and Tex. (San Augustine Co.); Me. to la., s. to Va., Ala., Miss., Tex. and Okla. 

9. Scirpus fontinalis Harper. 

Resembling S. lineatus, tufted short-lived perennial; culms 9-12 dm. tall, ob- 
tusely angled; leaves basal and cauline, the cauline 10 or less per culms; blades 
to 5 dm. long. 8-12 mm. wide; sheath ventral surface purple spotted; inflorescence 
decompound, the branches mostly ascending; bracts reduced or largest similar to 
blades. 1 per branch, tubular-sheathing; spikelets solitary, ovoid to lanceolate, 
4-8 mm. long, about 2 mm. broad, sessile or scaberulous-pedicellate; scales brown 
or reddish, lustrous, green-keeled. 1.5-2 mm. long, acuminate to cuspidate; 
achenes yellowish or brownish, smooth, trigonous or plano-convex, ellipsoid, 
0.7-1 mm. long, stipitate; bristles numerous, reddish, crinkly, smoothish. shorter 
than to slightly exceeding achene. 

Swamp forests, usually over marl. Coastal Plain, Va. to Fla., w. to Okla. 
{Waterfall). 

10 Scirpus molestus M C. Johnst. 

Tufted annual; culms 5-16 cm. long, grayish-green, compressed. 0.2-0.25 mm. 
thick, minutely striate, ascending, often somewhat flexuous or arcuate; sheaths 
short, slightly loose, quite smooth at the hyaline apical-ventral orifice, grayish- 
green, eventually turning brownish-stramineous, never red or purple; blades 2-3 
cm. long, tightly involute, arcuate-setaceous, about as thick as the culms; bract 
solitary, appearing as a continuation of (and as thick as) the culm, 5-10 (-23) 
mm. long; inflorescence a glomcrule of 2 or 3 spikelets, less commonly a solitary 
spikelet; spikelet 2-7 mm. long, ovoid to lance-ovoid, of (10 to) 20 to 30 flowers; 
scales never purplish or reddish, promptly and serially deciduous after anthesis, 
beginning at the bottom of the spikelet. the lowest scale larger than the rest; 
the second or third scale from the bottom 1-1.3 mm. long, gibbous, strongly 
arcuate-convex, broadly ovate, acute, the midnerve forming a broad grayish- 
green keel and mucro, the sides translucent, thin-membranous, unpigmented, 
cellular, with 1 or 2 acrodomc veins near the keel on each side; perianth bristles 
absent; stamens 2; filaments about as long as the achenes; anthers minute; style 
3-branched: achene globose-trigonous, basally rounded or minutely stipitate, 
apically rounded or extremely minutely apiculate, 0.8-0.9 mm. long, the 3 angles 
about equally prominent, the sides flat or slightly concave, surficially pinkish- 
brownish with numerous vertical rows of very minute pits, this pattern and color 
obscured by a more or less thick whitish-waxy coat. 

354 



Frequent in moist or wet sand, often associated with S. koilolepis, e. and s.e. 
Tex., spring; Ark., La. and Tex. 

11. Scirpus koilolepis (Steud.) Gl. 

Tufted annual: roots fibrous; culms cespitose, 4-22 cm. long, dark-grayish- 
green, compressed, 0.3-0.35 mm. thick, minutely striate, ascending, often some- 
what flexuous or arcuate; blades 2-5 cm. long, arcuate-setaceous; bract solitary, 
appearing as a continuation of (and as thick as) the culm, (13-) 17-33 mm. long; 
inflorescence of 1 or less commonly 2 spikelets; spikelets 3-7 mm. long, narrowly 
ovoid, acute, of (7 to) 10 to 14 flowers; scales never purplish or reddish, tardily 
serially deciduous; lowest scale larger than the rest; second or third scale from 
the bottom 2-2.5 mm. long, ovate, acuminate, strongly gibbous, arcuate-convex, 
the midnerve forming a broad grayish-green keel and mucro or apiculus, the 
sides translucent, membranous, cellular, with 1 to 3 acrodome veins near the keel 
on each side; perianth bristles absent; style 3-branched; achene globose to globose- 
oblong, trigonous, basally rounded or shortly stipitate, apically rounded or usually 
minutely apiculate. 1.3-1.5 mm. long, the 3 angles about equally prominent, the 
sides flat or slightly convex, surficially brownish, with numerous vertical rows 
of very minute pits and a thin whitish-waxy-bloom. 

Frequent in moist sandy loam, in bogs about lakes and ponds, depressions and 
marshes in coastal prairies and seepage areas, in Okla. (Johnston Co.), e., s.e., and 
n.-cen. Tex., rare in Edwards Plateau (Burnet Co.), spring; Ga., Tenn. and Ala. 
to Okla. and Tex.; Calif. 

12. Scirpus supinus L. Fig. 180. 

Tufted annual; culms 3-35 cm. long, 0.6-1.8 mm. thick, essentially terete 
(ridged on drying), not or only obscurely and bluntly trigonous; sheaths somewhat 
loose, apically oblique and acute, essentially bladeless; lower bract appearing 
as a continuation of the culm, (1-) 3-10 (-15) cm. long; other bracts much- 
reduced, very inconspicuous; inflorescence a glomerule of 2 to 8 spikelets or occa- 
sionally some of these extended on peduncles 1-3 cm. long; spikelets lance-ovate, 
4-11 mm. long, of 16 to 36 flowers; scales somewhat convex basally, ovate, 
acuminate, acute, with a very strong keel (green turning stramineous) and sides 
which are green-membranous turning firm and buff"y to purple; style 2-branched 
[var. Hallii (Gray) Gray] or 3-branched [var. saximontanus (Fern.) Koyama]; 
bristles variable; achenes 1.3-1.5 mm. long, glabrous, to broadly elliptic, in tran- 
section either plano-convex (var. Hallii) or strongly trigonous (var. saximontanus) 
and surficially with horizontal ridges or wrinkles. 

Frequent in moist areas near the coast and in mud about lakes and ponds, s.e. 
Tex. and Rio Grande Plains (both varieties), rare in n.-cen. Tex. and Plains 
Country (var. saximontanus), spring-summer; var. supinus is widespread in temp, 
parts of the world; var. Hallii in e. U.S. mainly Coastal Plain; var. saximontanus 
in Great Plains, N.D. to Tex. 

Scirpus "supinus." in the present broad sense, has only recently been treated as 
several narrowly defined species, of which three are attributed to our area and are 
characterized as follows: 

S. Wilkensii Schuyler. Styles mostly 2-parted and achenes 2-angled; scales 
mostly 1.9-2.3 mm. wide, the cells at the upper margin of the ventral surface 2 
to 5 times as long as wide; spikelet achenes mostly 1-1.2 mm. wide, with narrow 
acute transverse ridges. 

Ditches, swales and pond margins, s. Tex. (Aransas, Atascosa, Kleberg, Nueces 
and Willacy cos.) spr.-fall; also Tarn. 

S. saximontanus Fern. Style mostly 3-parted and achenes 3-angled; scales usually 
longer than wide; spikelet achenes with more than 15 narrow transverse ridges. 

355 




^J'%- 






d 




i^i' 







Fig. 180: a-e, Scirpus Olncyi: a, habit, X Mi; b, cross section of culm, X 4; c, in- 
florescence, X 1; d, scale, X 5; e, achene, X 8. f-j, Scirpus supinus var. Hallii: f. habit, 
X ift; g. inflorescence, X l~-x, h. achene in scale, X 12; i, scale spread out, X 12; j, 
achene, X 12. (Courtesy of R. K. Godfrey). 



Local in ditches, sink-lakes, ponds and wet prairies, e. (Austin Co.) and s. 
(Aransas, Bexar, Cameron, Hidalgo, Nueces and San Patricio cos.) Tex., Plains 
Country (Tom Green Co.) and Panhandle (Hale and Lynn cos.), spr.-fall; Kan., 
Mo., Neb., O., Okla. (Comanche Co.), S.D., Tex., Wyo., S.L.P. and Tarn. 

S. Bergsonii Schuyler. Styles mostly 3 -parted and achenes 3-angled; scales 
broadly ovate, mostly 2.1-2.9 mm. long and 2.2-3 mm. wide; spikelet achenes 
with fewer than 15 firm undulating transverse ridges. 

Local in ditches and on pond margins in s. Tex., (Kenedy, Kleberg and Nueces 
COS.), summer-fall; endemic. Said to hybridize with S. Wilkensii in Kenedy and 
Nueces counties. 

13. Scirpus americanus Pers. var. longispicatus Britt. Sword-grass, three-square 

BULRUSH. Fig. 181. 

Rhizomatous perennial; rhizomes extensively creeping, reddish-brown, 2-3 mm. 
thick; culms rising at short intervals, (1-) 3-15 dm. long, 2-6 mm. thick, ascend- 
ing in the distal half sharply triquetrous and often somewhat nodding; leaves 2 to 

4, usually 2, with involute blades several cm. long; principal bract solitary, appear- 
ing as a continuation of the stem, (15-) 30-50 (-155) mm. long; (lower scales 
of the spikelets often much longer than the rest and with strong venation, bract- 
like); inflorescence a solitary spikelet or a glomerule of 2 to 4 spikelets; spikelets 
sessile, 7-17 mm. long, 4-5 mm. thick, narrowly ovoid or lance-ovoid, of 28 to 50 
flowers; scales (except lowest) obovoid, brown, 4-5 mm. long, lower ones 
emarginate, with a well-marked buffy midnerve (prolonged into a short awn) and 
firm to membranous deep-brown sides; bristles about 4, about equaling the achene, 
retrorsely barbellate; style 3-branched, less commonly 2-branched; achene 2.5-3 
mm. long, 1.8-2.5 mm. broad, broadly obovate, apiculate, plano-convex, smooth, 
dark-brown when mature. Some of our plants have been known incorrectly as 
var. polyphyllus (Boeck.) Beetle. 

Essentially throughout our region in low often moist ground, in water and 
about seepage areas, spring-summer; nearly throughout temp, parts of the world. 

14. Scirpus OIneyi E. & G. Fig. 180. 

Rhizomatous perennial; rhizomes extensive, 2-4 mm. thick; culms rising at 
intervals, 6-20 dm. long, 4-8 mm. thick, sharply triquetrous most of the length 
(the sides often concave); leaves crowded at the base, usually 2 or 3, the lowest 
ones with loose membranous sheaths and reduced or obsolete, the upper one 
(which still appears basal) with a slightly longer blade; principal bract solitary, 
appearing as a continuation of the stem, 1-4 (-15) cm. long; (lower scales of the 
spikelets not differentiated from the rest); inflorescence a dense glomerule of 5 to 
15 spikelets: spikelets sessile, 5-8 (-12) mm. long, 3-5 mm. thick, mostly ovoid, 
of 24 to 30 (to 40) flowers; scales 3-4 mm. long, the lower ones emarginate, 
brown, the midrib paler, prolonged as a mucro; bristles about 4, about equaling 
the achene, retrorsely barbellate; style usually 2-branched, less commonly 3- 
branched; achene 1.8-2.6 mm. long, 1.5-1.8 mm. broad, obovate, apiculate, plano- 
convex or unequally biconvex. Our plants have been known incorrectly as 

5. chilensis Nees. 

Rare and scattered, wet alkaline or marshy soil, s.e. and e. Tex., Trans-Pecos, 
Plains Country and probably elsewhere, N.M. (Grant, Otero and Socorro cos.) 
and Ariz. (Apache and Coconino, s. to Cochise, Santa Cruz and Pima cos.), 
spring-summer; temp. N.A.; also Br. Hond., Venez. and Chile. 

15. Scirpus californicus (C.A. Mey.) Steud. Giant Bulrush, Tule. Fig. 182. 

Perennial from tight subrhizomatous knots; culms closely tufted, 1-2 mm. long, 
8-22 mm. thick near the base, 2-4 mm. thick near the inflorescence, bluntly tri- 

357 




Fig. 181: Scirpiis americanus: a, habit, X '!•; b. scale, X 12; c, achene, X 12; d, 
cross section of stem, X 14. (Courtesy of R. K. Godfrey). 




Fig. 182: a-d, Scirpus validus: a, habit, X l^; b, cross section of upper stem, X 1; 
c, scale, X 7; d, achene, X 10. e-h, Scirpus californicus: e, cross section of upper stem, 
X 1; f, sheath, X 1; g, scale, X 7; h, achene, X 10. (Courtesy of R. K. Godfrey). 



gonous; leaves few, basal, consisting only of mostly open brownish sheaths whose 
margins are rather regularly retrorsely fimbriate-filiferous: primary bract appear- 
ing as a continuation of the culm, 18-70 mm. long (other bracts reduced, scale- 
like), shorter than the inflorescence; inflorescence 4-12 cm. long, decompound 
with a number of usually drooping branches, altogether with 50 to 150 spikelets; 
spikelets lance-ovoid, 6-1 1 mm. long, of 30 to 50 flowers; scales about 3 mm. 
long, ovate to obovate, dark-brown, some of them emarginate, mucronate, the 
distal margins essentially entire; bristles 2 to 4, subligulate, reddish-brown, each 
one on each side with 15 to 20 reddish-brown closely spaced spreading or often 
somewhat retrorse projections (not barbellate); styles mostly bifid; achene obovate, 
apiculate, about 2 mm. long, brown, plano-convex or biconvex. 

Scattered in mud and shallow water of ponds and lakes throughout Tex. except 
the Plains Country, Okla. (Creek, Sequoyah and Stephens cos.), N. M. (McKinley 
and Rio Arriba cos.) and Ariz. (Mohave, Maricopa, Pima, Santa Cruz and Yuma 
COS.), spring-summer; warmer parts of Am., n. to Gulf States, s. Ariz, and s. 
Calif. 

16. Scirpus heterochaetus Chase. 

Similar to S. acutiis; culms slender, rarely 1 cm. thick, pale green, firm; panicle 
with ascending to spreading very slender smooth to barely scabrous rays; bract- 
lets whitish-brown, glabrous; spikelets mostly solitary, pale-brown to drab or 
whitish-green, lance-acuminate to slenderly ellipsoid, acute to subacuminate, 
7.5-23 mm. long; scales firm or subcoriaceous, deeply emarginate, often slightly 
red-dotted, glabrous; bristles 2 to 4 (mostly 2), fragile, unequal, shorter than 
achene, barbellate or smooth; filaments broad; style 3-cleft; achene trigonous but 
twice as broad as thick. 

Calcareous or other basic deadwaters, shores and swamps, in Okla. (Waterfall), 
June-Sept; e. Mass., s.w. Que., w. Vt. and n. N.Y., Wise, to N.D., s. to cen. Ky., 
111., Mo. and Okla.; n.w. Ida., Wash, and Ore. 

17. Scirpus etuberculatus (Steud.) O. Ktze. Fig. 183. 

Culm 1-2 m. tall, 3-angled (usually sharply so above, obtusely so below), the 
sheath at base extended into a long slender triangular and channeled leaf; in- 
volucral leaf similar (1-2.5 dm. long), continuing the culm; spikelets cylindric 
(1-2 cm. long), single or sometimes proliferously 2 or 3 together, nodding on the 
apices of the 5 to 9 long filiform and flattened peduncles or rays of the dichotom- 
ous umbel-like corymb, or the central one nearly sessile; scales loosely imbricated 
oblong-ovate, acute, pale, thin and scarious, with a greenish nerved back; bristles 
6, firm, furnished above with spreading hairs rather than barbs, equaling the 
slender abrupt beak of the obovoid-triangular shining achene 2.5-3 mm. (-4) long. 

Ponds (in 1 to 3 ft. of water) and fresh to brackish marshes, very local, Fla. 
to s.e. Tex. (Hardin Co.), n. to Del. and Mo. 

Often with a 2nd involucral bract, in this character and in its achene and 
bristles showing alliance with S. fluviatilis. 

18. Scirpus acutus Muhl. Hard-stem bulrush, Tule, great bulrush. Fig. 184. 

Rhizomatous perennial forming extensive colonies; culms 1-3 m. long, rising 
at close intervals from the rhizomes, 8-23 mm. thick near the base, long-tapered, 
2-4 mm. thick just under the inflorescence, essentially terete to very obscurely 
trigonous; leaves 1 or 2 per culm, confined to the very base, consisting of short 
mostly open sheaths with nearly smooth to lacerate margins; blades obsolescent; 
bract appearing as a continuation of the culm, (5-) 10-30 (-55) mm. long, shorter 
than the inflorescence; inflorescence 3-10 cm. long, decompound, with several 
drooping primary branches and 10 to 35 spikelets; spikelets lance-ovoid, at 
maturity 8-15 mm. long, of 20 to 50 flowers; scales about 5 mm. long (the lower 

360 




Fig. 183: Scirpus etuherculatm: a, habit, X 1/3; b, section of aquatic leaf; c, section 
of terrestrial leaf; d, scale, X 6; achene, X 8. (Courtesy of R. K. Godfrey). 




Fig. 184: Scirpus acutus: a, mature achene, the subtending bristles with conspicuous 
retrorse barbs, X 8; b, spikelet, X 4; c, flower without the scale, X 12; d, carinate scale, 
showing the short awn and the cleft ciliate apex, X 8; e, achene (cross section), X 8; 
f, habit, showing stout rhizome, basal sheaths and erect culms, X Vr,; g and h, inflores- 
cences, showing variation, X -'-,. (From Mason, Fig. 157). 



ones emarginate), thin-membranous, pale-brown and with conspicuous elongate 
reddish glutinous spots (seen under a lens), the distal margin lacerate, the mid- 
nerve scabrous and projected as a mucro or short awn; bristles 4 to 6, about 
equaling the achene, retrorsely barbed, on each side of the bristle 10 to 16 well- 
spaced barbs; styles mostly 2-branched; achene obovate, apiculate, plano-convex 
or very unequally biconvex, (1.8-) 2.1-2.4 (-2.9) mm. long. 5. lacustris L. subsp. 
glauciis (Sm.) Hartm., S. Tabernaemontani Gmel., S. lacustris var. occidentalis 
Wats. 

Alkaline or calcareous mud, marshes, usually in water, in Okla. (Le Flore, 
Ottawa, Blaine, Cimarron, Comanche, Bryan and Texas cos.) in the Tex. Plains 
Country and Trans-Pecos, rare e. to n.-cen. Tex., widespread in N.M. and Ariz., 
spring-fall; Eur., much of temp. N. A. s. to Gulf States, Chih., Coah. and Calif. 

This is perhaps only a variety of S. lacustris. Some specimens from the Texas 
lower Rio Grande Plains seem to be intermediate between S. acutus and S. validus. 

19. Scirpus validus Vahl. Great or soft-stem bulrush. Fig. 182. 

Rhizomatous perennial forming extensive colonies; culms 1-3 m. long, rising 
at close intervals from the rhizomes, 8-23 mm. thick near the base, long-tapered, 
2-4 mm. thick just under the inflorescence, essentially terete or very obscurely 
trigonous; leaves 1 or 2 per culm, confined to the very base, consisting of short 
mostly open sheaths with nearly smooth to lacerate margins; blades obsolescent; 
bract appearing as a continuation of the culm, (5-) 10-30 (-55) mm. long, shorter 
than the inflorescence; inflorescence 3-10 cm. long, decompound, with several 
drooping primary branches and 20 to 120 spikelets; spikelets ovoid, 5-10 mm. 
long, of 20 to 50 flowers; scales obovate, 3-4 mm. long, firm-membranous, dark- 
brown, nearly smooth (occasionally with a few reddish gummy spots near the 
midnerve), the distal margin nearly smooth to slightly lacerate, the midnerve pro- 
jected as a mucro or short awn; bristles 4 to 6, mostly slightly surpassing the 
achene, retrorsely barbed (on each side of each bristle 10 to 16 well-spaced barbs); 
styles mostly 2-branched; achenes obovate, apiculate, plano-convex or very un- 
equally biconvex, (1.5-) 1.9-2.1 (-2.2) mm. long. S. lacustris var. condensatus 
Peck. 

In mud and usually in shallow water, Okla. (Alfalfa, Grady, Johnston and 
Stephens cos.), infrequent in scattered parts of e, s.e. and n.-cen. Tex. and Rio 
Grande Plains, N. M. (San Miguel and Taos cos.) and Ariz. (Coconino, Yavapai, 
Gila, Pinal, Cochise and Santa Cruz cos.), spring-fall; temp. N.A. s. to S.A. 

Perhaps only a variety of S. lacustris. 

3. Eriophonim L. Cotton-grass 

About 20 species in North Temperate and Arctic areas, with one in South 
Africa. 

1. Eriophorum polystachion L. 

Colonial from widely creeping rhizomes; culms subterete, mostly 2-6 dm. tall; 
leaves basal and cauline; blade well-developed, the lower ones usually somewhat 
elongate, 2-6 mm. wide, flat or essentially so for most of its length, becoming 
narrow and triangular or channeled toward the tip; uppermost culm leaf with well- 
developed blade usually equaling or exceeding the sheath; involucral bracts several, 
unequal. 2 or more of them noticeably foliaceous at least above the broadened 
more chartaceous base, the longest one usually surpassing or equaling the in- 
florescence; spikelets 2 to 8, most or all of them individually pedunculate, in a 
compact to open umbelliform cyme, the peduncle more or less compressed, smooth 
or sometimes minutely scabrous-hirtellous; scales tawny to brownish or blackish- 
green, very thin distally, the slender midrib attenuated distally and not reaching 

363 




Fig. 185: a-c, Fuirena scirpoidea: a, habit, X Vi; b, two views of scale, X 5; c, 
ovary and perianth scales, X 10. d and e, Fuirena squarrosa: d, two views of scale, X 5; 
e, ovary and perianth scales, X 10. f-j, Fuirena simplex: f, habit, X i-.; g. sheath and 
ligule, X 2\<,\ h, spikelet, X 3; i, two view of scale, X 5; j, ovary and perianth scales, 
X 10. (V. F.). 



the tip; anthers usually to about 4 mm. long; bristles numerous, white or nearly 
so; achenes blackish, 2-3 mm. long, broadly oblanceolate to obovate, 2 to 3 times 
as long as wide. E. angustifolium Honck. 

In wet bogs, cold swamps and marshes, in N. M. (Taos Co.), Apr.-Aug.; Nfld. 
to Ore. and N.M. 

4. Fuirena Rottb. Umbrella-grass 

Perennials, usually rhizomatous, the lowest leaves often with reduced blades, 
the upper 1, 2 or 3 leaves functioning as bracts with each subtending a very much 
condensed often glomerulelike inflorescence of 1 to 10 spikelets; spikelets globose 
to oblong-cylindric; scales numerous, spirally imbricate, usually pubescent, all 
fertile, usually obovate and awn-tipped (awn short in one species); perianth of 3 
stalked scalelike or paddlelike structures often thickened at maturity, often addi- 
tionally three perianth bristles alternating with these stalked structures; style 
branches 3; achene plumply trigonous, shiny, apically tapering into a more or 
less persistent indurate linear style base often nearly as long as the achenial body 
itself. 

The genus is related to, and should be included within, Scirpus, according to 
some authors. A small genus of 40 species in warmer regions of the world. 

1. All or nearly all blades reduced; awns of spikelet scales only about 1 mm. long, 
ascending 1. F. scirpoidea. 

1. Nearly all blades well-developed, only the lowest reduced; awns of spikelet 

scales usually 2-4 mm. long, often spreading apically (2) 

2(1 ). Each of the 3 prominent perianth parts with an acuminate apex which often 
arches toward the style 2. F. squarrosa. 

2. Each of the 3 prominent perianth parts with an acute, blunt or even emarginate 

apex and often subapically on the dorsal side with a mucro or a 
minute awn 3. F. simplex. 

1. Fuirena scirpoidea Michx. Fig. 185. 

Strongly rhizomatous; only the middle sheaths with small blades; inflorescences 
often only at the uppermost node and reduced to 1 to 3 spikelets; scales of spike- 
lets with very short straight awns; the 3 expanded perianth parts tapering to their 
acumens. . 

Rare in wet sand, s.e. Tex. (Aransas and San Patricio cos.), summer; coast- 
wise, Fla. and Ga. to Tex.; Cuba. 

2. Fuirena squarrosa Michx. Fig. 185. 

Scales of spikelet with long often decurved awns; expanded perianth parts 
tapering to the nonmucronate acumen which is often incurved to the style. 
F. hispida Ell., F. breviseta Cov. 

Frequently in usually acid soils of marshes and bogs, e. and s.e. Tex., s. to 
Aransas Co. and Okla. {Waterfall), summer; parts of e. U.S. w. to e. Okla. and 
Tex.; Cuba, P.R. 

3. Fuirena simplex Vahl. Fig. 1 85. 

Scales of spikelet with long awns; expanded perianth parts variable but usually 
apically blunt or refuse and dorsally just below the tip with a mucro or minute 
awn. 

Frequent in wet areas, about springs, in shallow water on edge of ponds and 
lakes, usually in calcareous mud, Okla. (Love, Stephens, McCurtain, Comanche 
and Grady cos.), w. part of Tex., e. to n.-cen. Tex. and Rio Grande Plains and 
N. M. (Eddy co.), later summer-fall; Guat. and Br. Hond. n.w. to Mo., Neb., 
N.M., Son. and Baja Calif. 

365 



5. Eleocharis R. Br. Spikerush 

Annual or perennial broomlike sedges usually in aquatic environments; leaves 
reduced to mere bladeless sheaths; inflorescence solitary, terminal, spiciform (the 
bract reduced to a mere basal scale or usually absent), bearing few to many 
perfect flowers crowded in 3 to many ranks; scales spirally imbricate or rarely 
distichous (as in E. Baldwinii and perhaps E. minima), usually closely crowded, 
remaining so even when the achenes mature in some species (in others serially 
deciduous starting at the base of the spike), of various textures but always glabrous; 
perianth bristles 6 to 9 (or in some species reduced or absent); stamens usually 3, 
in some species often reduced to 2 or 1; styles 2- or 3-branched, basally enlarged 
into a persistent base (called the "tubercle") capping the achene, with a post- 
anthetic zone of abscission between this base and the more slender portion, 
variously shaped and textured, either well-demarcated from the body of the 
achene or appearing to merge with it (as in E. parvula and E. obtusa, etc.); achene 
body plano-convex or isolaterally or isosceleslike trigonous (the trigony often 
obscure) to nearly terete, of various shapes, textures, colors and surficial sculptur- 
ing. 

A cosmopolitan genus said to comprise about 200 species. 

1. Tubercle 1.2-1.7 mm. long, about as broad as the body of the achene 

1. E. tuberculosa. 

1. Tubercle less than 1.1 mm. long (2) 

2(1). Achenes with about 6 longitudinal ridges with fine horizontal lines (tra- 
beculae) between the ridges (3) 

2. Achenes various but not trabeculate (6) 

3(2). Culms strongly compressed, 2-edged, often C-shaped in transection, 0.6-1.3 
mm. broad 2. E. Wolfii. 

3. Culms neither strongly compressed nor 2-edged (4) 

4(3). Anthers 0.5-1 mm. long 3. E. acicularis. 

4. Anthers less than 0.5 mm. long (5) 

5(4). Anthers 0.3-0.4 mm. long; perennial with creeping rootstocks 

4. E. radicans. 

5. Anthers 0.25-0.4 mm. long; aimual, forming dense tufts 5. E. bella. 

6(2). Culms sharply triquetrous or quadrangular in transection, 2.5-4 mm. broad 
across each side, 5-8 dm. long (7) 

6. Culms not as above, if triquetrous or quadrangular then much less coarse (8) 

7(6). Culms quadrangular; achenial body 1.7-2.3 mm. long; tubercle 1-1.5 mm. 
long 6. E. quadrangulata. 

7. Culms triquetrous; achenial body 1.4-1.7 mm. long; tubercle 0.7-1 mm. long 

7. E. fistulosa. 

8(6). Tubercle coronalike, 0.3-0.5 mm. high, 0.8-1 mm. broad, capping and 

often broader than the trigonous obpyramidal body 

8. E. melanocarpa. 

8. Tubercle not as above, if coronalike then the body not trigonous (9) 

9(8). Achene biconvex, lustrous, brown when mature; style branches 2; tubercle 
forming a narrow lamelliform cap on and in outline confluent with 
the body (10) 

9. Achene trigonous or biconvex, if biconvex then the style branches 3 and/ or 

the tubercle not lamelliform (11) 

10(9). Spikelcts lanceolate, acuminate; scales acute 9. E. lanceolata. 

10. Spikelets broadly ovoid to ovoid-cylindric, obtuse; scales obtuse.... 10. E. obtusa. 

366 



11(9). Culms 1.5-9 mm. thick; spikelets of 40 to 350 flowers; achenes bicon- 
vex (12) 

11. Culms 0.1-1.4 mm. thick; spikelets of 5 to 80 flowers; achenes either bicon- 

vex or trigonous (16) 

12(11). Culms with complete septa (as revealed by dissection) (13) 

12. Culms not septate or irregularly and incompletely septate (15) 

13(12). Culms 1.5-3.5 mm. thick; septa 2-5 mm. apart; tubercle depressed, 
0.1-0.2 mm. high, in outline confluent with the body; body of 
achene 0.9-1.1 mm. long 11. E. montatia. 

13. Culms 4-9 mm. thick; septa mostly farther apart; tubercle conic, 1-1.2 mm. 

long; body of achene 1.8-2.2 mm. long (14) 

14(13). Septa very crowded just below the spikelet 12. E. interstincta. 

14. Septa not very crowded just below the spikelet 13. E. equisetoides. 

15(12). Body of achene about 2 mm. long, the surface cellular, appearing as if 
embedded in plastic; scales obtuse; spikelet 19-36 mm. long, cylin- 
dric 14. E. cellulosa. 

15. Body of achene 1.2-1.8 mm. long, surface smooth or micropunctate; scales 

usually acute; spikelets 8-25 mm. long 15. E. macrostachya. 

16(11). Achenes biconvex, lustrous, black when mature, the bodies 0.5-1 mm. 
long; tubercles 0.05-0.2 mm. long; style branches 2(17) 

16. Achenes trigonous or if obscurely so then not black when mature (19) 

17(16). Perennial usually with slender rhizomes; flowers 15 to 25 per spikelet; 
scales obviously keeled 16. E. flavescens. 

17. Annuals, densely tufted; flowers 28 to 80 per spikelet; scales not or incon- 

spicuously keeled (18) 

18(17). Body of achene 0.7-1 mm. long; tubercle 0.1-0.2 mm. long; culms 
0.4-1 mm. thick 17. E. caribaea. 

18. Body of achene 0.5-0.6 mm. long; tubercle 0.05 mm. long; culms 0.2-0.3 

mm. thick 18. E. atropurpurea. 

19(16). Body of achene rather sharply trigonous, broadest near the middle, 
apically confluent in outline with the tubercle which is pyramidal 
and 0.1-0.2 mm. long; rhizomatous mat-formers; culms 2-12 cm. 
long, 0.1-0.4 mm. thick 19. E. parvula. 

19. Body of achene either not sharply trigonous or (if so) not confluent with the 

tubercle, or else plants otherwise habitally (20) 

20(19). Tubercle columnar or slightly tapered, blunt, 0.6-1 mm. long, con- 
fluent with the body of the achene (21) 

20. Tubercle shorter or if as much as 0.6-1 mm. long then constricted basally, 

not confluent (22) 

21(20). Culms usually less than 1 mm. wide, not flattened; spikelets 4-7 mm. 
long, mostly of 2 to 7 flowers; achene reticulate 20. E. pauciflora. 

21. Culms usually over 1 mm. wide, flattened; spikelets 8-17 mm. long, mostly of 

12 to 30 flowers; achene smooth 21. E. rostellata. 

22(20). Tubercle 0.6-1 mm. long, high-pyramidal, basally truncate; body of 
achene 1.2-1.7 mm. long, surficially cellular (the cells with promi- 
nent margins) and olivaceous brown to olivaceous gray when ma- 
ture 22. E. tortilis. 

22. Tubercle 0.05-0.7 mm. long, mostly pyramidal, low to depressed-pyramidal 

or globose; body of achene 0.5-1.8 mm. long, surficially smooth to 
warty or punctate but not cancellate, variously colored (23) 

367 



23(22). Spikelets of 5 to 20 flowers; culms 0.1-0.3 mm. thick; achenes rather 
sharply trigonous, mostly whitish or maturing to shades of olive, 
surficially smooth; sheaths long-oblique apically (24) 

23. Spikelets of 20 to 110 flowers; culms 0.2-1.4 mm. thick; achenes mostly not 

so sharply trigonous (except in E. tenuis, E. cylindrica and E. 
austrotexana), maturing (except in E. tenuis and E. elongata) through 
shades of yellow to golden-brown or brown; sheaths truncate or 
only very slightly oblique apically (26) 

24. Spikelets ovoid, 2-5 mm. long; scales rarely appearing distichous (except in 

lance-elliptic, 3-4.5 mm. long, buffy to ferruginous-buflf 

23. E. Baldwinii. 

24. Spikelets ovoid, 2-5 mm. long; scales rarely appearing distichous (except in 

E. minimal), ovate, shorter, usually whitish to purplish (25) 

25(24). Culms about 0.1 mm. thick, strongly recurved, 3-7 (-10) cm. long; 
spikelets of 5 to 10 flowers; body of achene 0.7-0.8 mm. long, 
maturing through whitish or olive to olive-gray; tubercle pyramidal, 
0.15-0.3 mm. high 24. E. minima. 

25. Culms 0.1-0.3 mm. thick, mostly erect, 4-28 cm. long; spikelets of 8 to 15 

flowers; body of achene 0.5-0.6 mm. long, pearly white; tubercle 
depressed-pyramidal, 0.05-0.15 mm. high 25. E. microcarpa. 

26(23). Scales broadly ovate, subcartilaginous medially, firm-membranous mar- 
ginally, stramineous in color, somewhat lustrous; body of achene 
ripening through shades of olive-whitish to brownish-olive and 
finally to a rich dark-chocolate-brown; bristles conspicuous, reddish- 
brown at maturity 26. E. albida. 

26. Scales mostly thinner, membranous and usually with some dark pigmenta- 

tion (27) 

27(26). Body of achene light-green, with about 12 rows of coarse transversely 
linear ceHs; bristles 6 or 7, equaling the achene, greenish; culms 
often floating on the surface of water 27. E. elongata. 

11. Body of achene (except in E. tenuis) ripening through shades of yellow to 
golden-brown; bristles various but not as above (28) 

28(27). Body of achene minutely but pronouncedly warty or pitted in vertical 
lines, 0.6-0.8 mm. long, ripening through shades of ivory to 
greenish-olive; tubercle pronouncedly depressed, 0.1-0.2 mm. high, 

not much-constricted basally; culms 0.2-0.3 mm. thick 

28. E. tenuis. 

28. Body of achene minutely punctate-reticulate to smooth but not warty, 0.6-1.8 

mm. long, ripening through shades of yellow to brown; tubercle 
usually conic-globular, usually constricted basally; culms 0.4-1.4 
mm. thick (29) 

29(28). Scales of spikelet apically rounded, hyaline only in a very narrow 
rounded border at the apex (30) 

29. Scales of spikelet deltoid or ovate-acute to lance-acuminate, with a more or 

less acute more or less extensive hyaline apex (32) 

30(29). Spikelet lincar-cylindric, acute; body of achene distinctly trigonous, 
smooth and satiny 29. E. cylindrica. 

30. Spikelet linear-lanceolate or narrowly ovoid to oblong and apically blunt: 

body of achene obscurely trigonous (31) 

31(30). Spikelets linear to narrowly lanceolate, acuminate; achenes smooth or 
finely pitted; scales acute or acutish 30. E. Parishii. 

31. Spikelets ovoid to oblong, usually apically blunt; achenes punctulate-reticulate 

to nearly smooth; scales mostly obtuse 31. E. montevidensis. 

368 



32(29). Body of achene 1.2-1.8 mm. long; tubercle 0.2-0.7 mm. long; styles 
mostly 2-branched, rarely 3-branched (33) 

32. Body of achene 0.7-1.2 mm. long; tubercle 0.1-0.2 mm. long; styles 3- 

branched (34) 

33(32). Styles always 2-branched; body of achenes very faintly reticulate- 
punctulate to essentially smooth; common 15. E. macrostachya. 

33. Styles 2- or 3-branched; body of achene distinctly reticulate-punctulate; ex- 

ceedingly rare 32. E. fallax. 

34(32). Culms 30-45 cm. long, with complete septa at regular short intervals 
(as revealed by dissection); body of achene with at least 2 distinct 
angles, the third sometimes also fairly sharp, the surface essentially 

smooth; scales merely acute, about 2 mm. long 

33. E. austrotexana. 

34. Culms 8-28 cm. long, not septate; body of achene obscurely trigonous, ;he 

surface somewhat punctulate-reticulate; scales with long-acuminate 
scarious or hyaline apexes which often become split (bifid) during 
elongation (35) 

35(34). Culms strongly compressed, 0.6-1 mm. thick in the flat dimension; deep 
east Texas 34. E. compressa. 

35. Culms variable, somewhat to not at all compressed, 0.3-0.8 mm. thick; 

Edwards Plateau, Plains Country, s.e. Tex. and Okla 

35. E. acutisquamata. 

1. Eleocharis tuberculosa (Michx.) R. & S. Fig. 186. 

Tufted perennial, often with ascending rhizomes 3-6 mm. thick; culms 15-80 
cm. long, compressed, 0.5-1 mm. thick in the longer dimension, erect, wiry, 
sulcate, grayish-yellow; sheaths grayish-yellow, shortly oblique and acute; spikelets 
ovoid to lance-ovoid, 5-15 mm. long, blunt to acute, with 25 to 40 flowers; scales 
ovate to nearly orbicular, about 3 mm. long, blunt, grayish-yellow to stramineous, 
firm (chartaceous to subcartilaginous), not keeled, marginally slightly thinner than 
medially; bristles several, brownish, usually surpassing the achenial body; style 
3-branched; achenial body broadly obovoid, 1.2-1.7 mm. long, obscurely trigo- 
nous, stramineous to olivaceous, surficially with pronounced large cells (the cell- 
walls prominent), lustrous; tubercle 1.2-1.7 mm. long, irregularly stele-shaped- 
conic, apically rounded, toward the base flared out mushroomlike and as broad 
as the body, very strongly truncate, the connection to the body very thin. 

Frequent in moist sand, wet meadows, about lakes and ponds, and along 
streams, in s.e. and e. Tex., May-Nov.; coastal provinces and states, N.S. and 
N.H. to Tex.; also Tenn. and Ark. 

2. Eleocharis Wolfii (Gray) Patt. 

Perennial (?); rhizomes slender, creeping, fragile; culms tufted, 2-edged, 
somewhat concavo-convex or C-shaped in transection, 12-30 cm. long, 0.6-1.3 
mm. broad, erect; sheaths apically scarious, oblique; spikelets ovoid-lanceolate, 
acute, 5-10 mm. long, 18- to 34-flowered; scales narrowly ovate, acute, usually 
with 2 purple longitudinal stripes and the rest stramineous, firm or marginally 
scarious; bristles absent; style 3-branched; achenial bodies narrowly obovoid, 
0.8-0.9 mm. long, pearly, obscurely trigonous to terete, with about 9 longitudinal 
ridges and between each 2 ridges about 40 close horizontally elongate cells 
(trabeculae) ; tubercle depressed-conic, about 0.1 mm. long, much narrower than 
the body. 

Rare in wet sand and wet swales in prairies. Plains Country and s.e. Tex., 
probably scattered elsewhere, spring-summer; Sask., Ind., 111., Mo., Kan., Colo., 
(?) Okla., Tenn., La. and Tex. 

369 






Fig. 186: Eleocharis tuberculosa: a, habit, about X i/>; b, sheath, about X 5; spike- 
let, about X 8; d, achene, about X 15. (Courtesy of R. K. Godfrey). 









Fig. 187: a-d, Eleocharis acicularis: a, habit, X ^2; b, sheath, X 12; c, spikelet, X 8; 
d, achene, X 50. e, Eleocharis radicans: e, achene, X 50. (Courtesy of R. K. Godfrey). 



3. Eleocharis acicularis (L.) R. & S. Fig. 1 87. 

Rhizomatous perennial forming mats; roots not fleshy; rhizomes 0.3-0.6 mm. 
thick, extensively creeping; aerial culms 2-23 cm. long, 0.2-0.4 mm. thick, about 
8-costate and -sulcate, often somewhat flattened or angulate; sheaths thin, reddish 
below, pallid and membranous or hyaline terminally, oblique; spikelets narrowly 
ovoid to ovoid-elliptic, 2-5 mm. long, 5- to 15-flowered; scales membranous, whit- 
ish to usually dark-purplish-red (or marginally pallid), ovate, 1.5-2 mm. long, 
rather truncate to acute; bristles 3 or 4, or usually (in Texas material) reduced or 
absent; stamens 3, anthers 0.5-1 mm. long; styles 3-branched; achenial body 
obovoid, obscurely trigonous to usually nearly terete because of the turgid sides, 
0.5-0.7 mm. long, pearly-white, with a number of longitudinal ribs and between 
each 2 ribs 25 to 40 close horizontally elongate facets or cells; tubercle conic, 
0.075-0.15 mm. long, constricted basally, much narrower than the achenial body. 
E. Reverchonii Svens. 

Muddy river banks, meadows, vernal pools, edge of lakes and marshes, in Okla. 
(Kay and Alfalfa cos.), nearly throughout Tex. except Trans-Pecos and e. Tex., 
N. M. (San Miguel, Rio Arriba, Catron, San Juan, Socorro and Grant cos.) and 
Ariz. (Apache and Coconino cos.), infrequent or locally abundant, Feb.-summer; 
most n.-temp. areas of the world, in Am. s. to Calif., Chih., and the Gulf States. 

4. Eleocharis radicans (A. Dietr.) Kunth. Fig. 187. 

Densely matted perennial, the rhizomes very short; culms succulent (pressed 
flat in specimens), only 3-8 cm. long, 0.6-1 mm. thick, erect; sheaths mem- 
branous, tight; spikelets ovoid, 3-4 mm. long, 6- to 12-flowered; scales ovate- 
lanceolate, greenish-stramineous; bristles usually 4, slender, white, retrorsely 
toothed, variable in length, in some specimens reduced or absent; stamens 2, 
anthers 0.3-0.4 mm. long; style 3-branched; achenial bodies narrowly obovoid, 
0.7-0.9 mm. long, pearly, obscurely trigonous or usually essentially terete, with 
several longitudinal ridges and (between them) many (30 to 40) close horizon- 
tally elongate cells (trabeculae) in each longitudinal series; tubercle conic, 0.1-0.2 
mm. long, much narrower than the body. Scirpus radicans Poir. (an illegit. name), 
Eleogiton radicans A. Dietr., Eleocharis Lindheimeri (Clarke) Svens. 

Rare in marshy areas, wet sand and gravelly stream banks, in Okla. {Waterfall), 
e. and s.e. Tex. and Ariz. (Coconino, Pinal and Cochise cos.), spring (-summer?); 
Va., Mich., Tex., Okla., Ariz., Calif., Son., Gr. Ant., S.A.; H.I. 

5. Eleocharis bella (Piper) Svens. 

Dwarf annual with fibrous roots and caespitose culms, often forming dense 
round tufts 5-10 cm. in diameter; culms capillary, furrowed, 2-6 cm. tall, light 
green; basal leaf sheaths loose, obliquely truncated; spikelets 1-3 mm. long, 3- to 
15-flowered; scales with purplish brown sides and green midrib; bristles none; 
stamens 2, anthers 0.25-0.4 mm. long; stigmas 3; achenes white or cream-colored, 
0.6-0.8 mm. long, with numerous longitudinal ribs, about 30 fine transverse lines 
between the ribs; tubercle compressed-conical. 

Montane meadows, borders of marshes and lakes, wet, muddy or springy places, 
in Ariz. (Apache, Coconino and Cochise cos.); Mont., Ida. and Wash., s. to N.M. 
and Ariz. 

6. Eleocharis quadrangulata (Michx.) R. & S. Fig. 188. 

Tufted perennial; culms 5-8 dm. long, 2.5-4 mm. thick, erect, sharply 4-angled, 
not septate; sheaths membranous, brownish or less commonly reddish, apically 
oblique; spikelets cylindric, 20-42 mm. long, 3.5-4.5 mm. thick, with 40 to 90 
flowers; scales rotundly obovate to ovate, 5.5-6 mm. long, 3-5 mm. broad, 
medially nearly flat, stramineous and subcartilaginous, laterally broadly chartace- 

372 




Fig. 188: Eleocharis quadrangulata: a, habit, showing the rhizome, the basal leaf 
sheaths, the tall 4-angled culms, and the cylindric spikelets, X I5; b, flower, showing 
the rounded scale, the 3 stamens and the trifid style, X 6; c, mature achene, the 
tubercle elongated and triangular, and the slender subtending bristles, X 8; d, culm, 
showing the sharp angles (cross section), X 6; e, spikelet, X IVi. (From Mason, Fig. 
144). 





Fig. 189: Elcocharis mehinocarpa: a, habit, X if); b, sheath, X 3; c, spikelet, X 3; 
d, achene, X 30. (Courtesy of R. K. Godfrey). 



ous to hyaline, the distal margin with slightly darker coloration; bristles about 6, 
slender, unequal, some equaling the body, others surpassing the tubercle, with 
minute retrorse serrulations; style 2- or 3-branched; achene body biconvex to 
turgidly biconvex, 1.7-2.3 mm. long, brown (yellow when immature), shiny; 
tubercle high-conic to deltoid or oblong, 1-1.5 mm. long, 0.8-1 mm. broad, 
basally constricted, dark. 

Infrequent in mud and in shallow water at edge of ponds and lakes in Okla. 
(Le Flore, Pushmataha, Muskogee, Ottawa, Latimer and Atoka cos.) and in e. 
and s.e. Tex., rare in n. part of Rio Grande Plains, late spring-fall; most of e. 
U.S., w. to Wise, Mo., Okla. and Tex.; also Jal. 

7. Eleocharis fistulosa (Poir.) Schult. 

Tufted perennial, apparently rather similar to E. quadrangulata but the culms 
sharply triangular and the spikelets and scales averaging slightly smaller; achene 
body 1.4-1.7 mm. long; tubercle 0.7-1 mm. long. 

Rare in Tex., Rio Grande Plains, summer-fall (?); widely distributed in the 
warmer parts of the world, in Am. n. to Cuba and Tex. 

8. Eleocharis melanocarpa Torr. Fig. 189. 

Densely tufted perennial; culms 2-6 dm. long, flattened, about 1 mm. thick 
in the larger dimension, on each side paucicostate and paucisulcate; sheaths 
apically firm and thickened, mucronate; spikelets narrowly ovoid, obtuse, 6-12 
mm. long, 4-5 mm. thick, with 20 to 40 flowers; scales ovate, 3-3.5 mm. long, 
with a pale buffy very firm midrib, passing laterally through firm-brown to 
membranous-stramineous marginally; bristles dark-brown, shorter than the 
achene tubercle, retrorsely toothed or much-reduced; style 3-branched; achenial 
body obpyramidal-trigonous, 0.8-1 mm. long, apically truncate, ripening through 
fuscous to black, glossy; tubercle paler, caplike, 0.3-0.5 mm. long, 0.8-1 mm. 
broad, often broader than the body and overhanging its truncate apex, depressed 
centrally with a slight pointed umbo. 

Rare in moist sandy often boggy loam, e. Tex. (Leon and Upshur cos.), 
summer-fall (?); Coastal States, Mass. to Tex.; also Ind. and Mich. 

Plants of this species appear to combine some characters of E. rostellata and 
some of E. obtusa. 

9. Eleocharis lanceolata Fern. 

Densely tufted annual; culms 1-2 dm. long, 0.3-0.9 mm. thick, erect; sheaths 
apically firm and oblique; spikelets lanceolate to lance-ovoid, of 30 to 80 flowers, 
acute; scales ovate, firm, brownish-stramineous, with a narrow scarious margin, 
acute, falling promptly in series from bottom to top of spikelet; bristles 6 or 7, 
usually surpassing the tubercle; style 2- or 3-branched; achenial body 0.9-1.1 
mm. long, 0.7-0.8 mm. broad, biconvex, pyriform in outline, smooth, shiny, 
ripening to a brownish color; tubercle forming a dark broad low-deltoid crown 
on the body and in outline merging with it, not constricted basally, about 0.4 mm. 
long, 0.5-0.6 mm. broad. E. obtusa var. lanceolata (Fern.) Gilly. 

In moist or wet loamy soils and muddy margins of ponds and lakes, in Okla. 
(Mcintosh, Pittsburg. McCurtain, Atoka and Ottawa cos.) and in n.-cen. and 
n.e. Tex. (Grayson and Bowie cos.), summer-fall (?); Mo., Kan., Ark., Okla. and 
Tex. 

10. Eleocharis obtusa (Willd.) Schult. Fig. 190. 

Densely tufted annual (rarely persisting more than 1 season); culms 3-50 cm. 
long, 0.3-1.6 mm. thick (fleshy and sometimes seemingly broader when pressed 
flat), erect, striate; sheaths often slightly purplish basally, apically firm and 

375 







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Fig. 190: Eleocharis ohtusa: a. habit, X V.; b, sheath. X 12; c, spilcelet, X 8; d, 
achene, X 40. (Courtesy of R. K. Godfrey). 






Fig. 191: Eleocharis interstincta: a, habit, X %; b, sheath, X 3; c, spikelet, X 2; 
d, achene, X 10. (Courtesy of R. K. Godfrey). 



oblique; spikelets broadly ovoid to nearly cylindric, of 50 to 100 flowers (50 to 80 
in var. ohtusa, 60 to 100 in var. detonsa), obtuse; scales oblong to suborbicular, 
firm, drab-stramineous with a narrow scarious margin, obtuse, falling promptly 
in scries from bottom to top of spikelet; bristles several, varying from surpassing 
the tubercle to essentially absent; style 2- to 3-branched; achenial body biconvex, 
pyriform, 0.8-1.2 mm. long. 0.7-1 mm. broad, smooth and shiny, ripening through 
shades of yellow-green to brown; tubercle forming a dark broad low-deltoid crown 
on the body and in outline merging with it, not constricted basally, 0.1-4 mm. 
long, 0.5-1 mm. broad (in var. ohtusa the tubercle 1.7 to 3 times broader than 
long; in var. detonsa 2.8 to 4.5 times broader than long). E. Engehnannii Steud. 

Locally abundant in moist sandy soils, in wet meadows, shallow water of ponds 
and edge of lakes, and mud of swamps, in Okla. (widespread), N.M. (Catron, 
Eddy and Socorro cos.) and Ariz. (Apache and Coconino cos.), the var. ohtusa 
in e. and s.e. Tex. passing into var. detonsa (Gray) Drapalik & Mohlenbrock in 
n.-cen. Tex. and Edwards Plateau (Enchanted Rock area only), spring-summer; 
o\er much of temp. N.A. [and perhaps including the Euras. £". ovata (Roth) 
R. cSc S. as var. ovata (Roth) Drapalik & Mohlenbrock]. 

11. Eleocharis montana (H.B.K.) R. «fe S. 

Perennial, basally subrhizomatous but not extensive; culms densely tufted, 3-8 
dm. long. 1.5-3.5 mm. thick, erect, terete, with complete septa 2-3 mm. apart; 
sheaths basally reddish, apically lineolate. very firm, only very slightly oblique, 
mucronate; spikelets lanceolate, 8-24 mm. long, acute, with 110 to 240 (to 350) 
flowers; scales ovate and acute to broadly lanceolate, about 2 mm. long, medially 
burty-brown and membranous, marginally hyaline and paler; bristles 6 to 8, brown- 
ish, unequal, the longer ones about equaling the achenial body; style 2-branched 
(in Texas material); achenial body 0.9-1.1 mm. long, obovate. biconvex (not 
turgidly so), with 2 definite angles (in Texas material), ripening through shades 
of pallid chartreuse and yellow to olive-brown, surficially punctulate-reticulate; 
tubercle 0.1-0.2 mm. long, depressed-deltoid, about half as broad as the body 
and scarcely restricted basally, almost merging with the body. 

Scarce in wet places, s.e. Tex. and s. as far as Nueces Co., N.M. (rather 
widespread) and Ariz. (Pima and Pinal cos.), summer; widespread in S.A. and 
C.A., W.I., n. to Ariz., N.M., Tex., La. and Fla. 

12. Eleocharis intersHncta (Vahl) R. & S. Fig. 191. 

Tufted perennial; culms 5-10 dm. long, 4-9 mm. thick, erect, essentially terete, 
septate, the septa closer together as the spikelet is approached; sheaths often 
tinged dark-red, apically firm, oblique; spikelets cylindric, 22-42 mm. long, 5-7 
mm. thick, with SO to 140 flowers; scales (sub) cartilaginous, 3.5-5 mm. long and 
broad, obtuse, rounded, stramineous to buffy-stramineous, marginally darker and 
thinner, medially flat with a faint narrow midvein which is more heavily pig- 
mented distally; bristles 6, exceeding the achene, brownish, stout, subcartilaginous, 
flattened, with (usually rctrorse) serrulations; styles 2- or 3-branched; achene 
body biconvex, 1.8-2.2 mm. long, brown (\ellow when immature), shiny; tubercle 
high-conic, 1-1.2 mm. long, O.S mm. broad, dark, slightly constricted basally. 

Infrequent to rare in mud and in water on edge of streams, lakes and ponds, 
in e. Tex., Rio Grande Plains and Edwards Plateau, probably elsewhere, summer- 
fall; Fla.. Tex.. Berm.. W.l. s. to Bol. and Braz. 

13. Eleocharis eqiiisctoides (Fll.) Torr. Fig. 192. 

Tufted perennial, exceedingly similar to E. interstincta but the septa not as 
crowded just below the spikelet and the bristles slightly shorter and thinner on 
the average. 

378 




Fig. 192: Eleocharis equisetoides: a, habit, X Vs; b, sheath, X 3; c, spikelet, X 2; 
d, achene, X 8. (Courtesy of R. K. Godfrey). 




Fig. 193: Elencharis cellulosa: a, habit, X Vk b and c, two views of sheath, X 3; 
d, spiiie, X 4; e, achene, X 15. (Courtesy of R. K. Godfrey). 



Rare in water of lakes and ponds, in e. and s.e. Tex., summer-fall; Coastal 
States, Mass. to Tex.; also Ind., Mich., Wise, and Mo. 

14. Eleocharis cellulosa Torr. Fig. 193. 

Tufted perennial; culms 5-8 dm. long, 2-5 mm. thick, erect, essentially terete 
or irregularly compressed and striate; sheaths usually reddish, apically oblique, 
membranous; spikelets cylindric, 19-36 cm. long, 3.5-5 mm. thick, with 50 to 90 
flowers; scales broadly ovate to obovate, 5-6 mm. long, 3-3.5 mm. broad, medially 
with a prominent midrib and subcartilaginous and stramineous, striate and brown- 
penicillate, in texture passing laterally to chartaceous and finally to hyaline, in 
color to pallid-buff, the distal margin finely white-hyaline, submarginally with a 
thin brown line; bristles about 6, slender, mostly exceeding the achene and not 
serrulate; style 3-branched; achene body biconvex, about 2 mm. long, brownish, 
surficially distinctly cellular (the cells quadrangular, appearing as if embedded in 
clear plastic), apically umbonate (forming a buttonlike base which is the podium 
for and merges into the tubercle); tubercle conic-deltoid, 0.6-1 mm. long, 0.4-0.6 
mm. broad, dark, not at all constricted basally but appearing as a continuation 
of the umbo of the body although differing texturally (being noncellular). 

Infrequent in fresh-water and mud, occasionally forming mats in shallow 
water, and in depressions, in the Tex. Edwards Plateau, rare in Rio Grande 
Plains, exceedingly rare in e. Tex., spring-fall; Coastal States, N.C. to Tex.; 
Mex.;W.I.;Berm. 

15. Eleocharis niacrostachya Britt. Creeping spike rush. Fig. 194. 

Rhizomatous perennial; rhizomes 1-2.5 mm. thick, often reddish; culms in tufts 
along the rhizome, 18-50 cm. long, 0.9-3 mm. thick, erect, often appearing 
slightly spongiose and irregularly sulcate on drying, occasionally compressed; 
sheaths tight, apically truncate or very slightly oblique, very firm, in many speci- 
mens mucronate, basally dark-reddish-brown; spikelets 8-25 mm. long, 3 mm. 
thick, lanceolate or linear-lanceolate, acute, of 40 to 100 flowers; lowest 1 to 3 
scales sterile, firm, obtuse, the lowest one sometimes completely encircling the 
base of the spikelet; fertile scales lanceolate to broadly lanceolate, more or less 
acute, about 3 mm. long, with a green or stramineous midrib (which does not 
reach the apex), a firm buffy to castaneous lateral and subapical zone and a hya- 
line margin and apex; bristles 7 or 8, brownish, unequal, the longest usually as 
long as the tubercle; style 2-branched, the upper part promptly deciduous from 
the base; achenial body obovate to pyriform, 1.2-1.8 mm. long, usually more 
turgidly convex on one (abaxial) side than on the other, surficially nearly smooth 
or very faintly reticulate-punctate in an open pattern, lustrous, ripening through 
shades of yellow to golden-brown; tubercle 0.3-0.7 mm. long, conic to depressed 
or even subglobular, grayish, texturally like pumice or rotted bone, usually about 
half as broad as the body, basally constricted. Some workers refer these plants to 
the Old World complex known by the name E. palustris (L.) R. & S., (?) E. calva 
Torr., E. xyridiformis Fern. & Brack. 

Common and widespread in most of our area, in marshes, vernal pools, wet 
meadows, ditches, flooded lands and alkaline mud, spring-summer; Minn, to III., 
Mo., Kan., Okla. and Tex., w. to s. Alas., Calif, and s. to cen. Mex.; Col. 

16. Eleocharis flavescens (Poir.) Urban. Fig. 195. 

Perennial, often with elongate fleshy rhizomes 0.5-1 mm. thick; culms either 
densely tufted or rising singly from the nodes of the rhizome, 4-35 cm. long, 0.3- 
1 mm. thick, ascending, firm to flaccid, often sulcate when dried; sheaths apically 
oblique, hyaline, fragile, promptly becoming loose and withered on drying; spike- 
lets 3-6 mm. long, ovoid, acute or blunt, with 15 to 25 flowers at maturity (the 

381 




Fig. 194: EleocUaris macrostachya: a, habit, showing the tall erect culms with 
truncate hasal leaf sheaths and the creeping rhizomes, X %; b-g, variations in form and 
size of achene. tubercle and subtending bristles, X 12; h, flowers, showing the lanceolate 
scale, X 6; i, terminal spike, the lower scales empty. X 2. (From Mason, Fig. 143). 




Fig. 195: Eleocharis flavescens: a, habit, showing a tufted plant and rhizomes with 
single culms arising from the nodes, X %; b, ovate obtuse spikelet, X 6; c, emarginate 
basal leaf sheaths, X 6; d, mature achene, the tubercle conic and acute, the subtending 
bristles as long as or slightly longer than achene, X 24; e, elliptic scale with pale mid- 
vein, X 20; f, flower, showing the bifid style and the 3 stamens, X 20. (From Mason, 
Fig. 139). 



numerous more apically situated primordia never maturing) ; scales ovate to ovate- 
oblong, firm to membranous, somewhat striate, with a strong greenish keel-like 
midrib and brown-stramineous sides; bristles about 7, pallid to pure white, quite 
variable in length but usually about equaling the tubercle; style 2-branched; 
achenial body obovate to pyriform, 0.8-0.9 (-1) mm. long, biconvex, shining, 
microscopically pitted, ripening through shades of chartreuse and olive brown 
to purplish-brown or even purplish-black; tubercle conic, yellow to greenish-white, 
acute, 0.1-0.2 mm. long, about 0.1 mm. broad, basally very slightly constricted. 
E. olivacea Torr., E. ocreata (Nees) Steud. 

Rare in moist soil, on mud and in shallow water, sometimes on floating logs, 
in e. and s.e. Tex. and Edwards Plateau, probably elsewhere, and Ariz. (Pima 
Co.), spring-fall; e. N.A. w. to Minn, and Tex.; Ariz, and Calif.; V/.I., Mex., 
S.A. Easily confused with E. caribaea. 

17. Eleocharis caribaea (Rottb.) Blake. Fig. 196. 

Densely tufted annual (when plants are covered slowly with shifting sand the 
bases elongating upward somewhat like rhizomes) or perhaps rarely perennial; 
culms 4-30 cm. long, 0.4-1 mm. thick, terete (or striate and sulcate on drying); 
sheaths apically oblique, firm; spikelet 3-6 mm. long, ovoid to broadly ovoid, 
obtuse, of 28 to 50 flowers; scales broadly ovate, 1.5-2 mm. long, firm, when 
mature stramineous to pallid-buff'y and with inconspicuous midrib, obtuse, even- 
tually serially deciduous from lowest to highest; bristles about 7, dark-colored, 
usually about equaling the tubercle; style 2-branched; achenial body (0.7-) 
0.8-1 mm. long, obovate to pyriform in outline, biconvex, ripening through 
shades of pale-green to purplish-black, shiny; tubercle conic (depressed or acute), 
(0.05-) 0.1-0.2 mm. long, pallid-greenish or whitish, slightly constricted basally. 

Locally abundant in moist calcareous soil, wet mud, wet lake shore and 
streams, in Okla. (Carter, Love and Stephens cos.), in most parts of Tex. (absent 
from Plains Country and e. Tex.), and Ariz. (Gila and Pima cos.), summer-fall; 
widespread in warmer parts of the world; in Am. n. to Gulf States, casual 
elsewhere. 

Has been known incorrectly as E. geniculata (L.) R. & S.; the latter is a species 
of coarse, tropical perennials not occurring in our region. 

18. Eleocharis atropurpurea (Retz.) J. & C. Presl. Fig. 196. 

Densely tufted annual; culms 3-12 cm. long, 0.2-0.3 mm. thick, arcuate- 
erect, terete (sulcate or striate on drying); sheaths apically oblique, firm; spikelet 
narrowly ovoid, 2-4 mm. long, of 40 to 80 flowers; scales ovate to narrowly so, 
about 1 mm. long, obtuse to abruptly acute, firm-membranous, with a green 
midrib, brown to purplish laterally; bristles several, usually colorless, translucent, 
about equaling the achenial body or much-reduced; style 2-branched; achenial 
body 0.5-0.6 (-0.7) mm. long, obovate to pyriform in outline, biconvex, when 
mature quite jet black, shiny; tubercle conic, about 0.05 mm. long, whitish, 
constricted basally. 

Rare and local in moist sandy soil, in mud along streams and marshes in Okla. 
(Blaine and Alfalfa cos.), e. Tex. (Bastrop Co.), Edwards Plateau (Burnet Co.), 
Plains Country (Hale Co.) and Rio Grande Plains (Hidalgo Co.), and N. M. 
(Sandoval Co.), scattered, summer; scattered in warmer parts of both hemis- 
pheres, in Am. n. to la.. Neb., Colo, and Wash. 

19. Eleocharis parvula (R. «& S.) Link. Fig. 197. 

Tufted annual (?) spreading by short stolons or rhizomes 0.2-0.5 mm. thick, 
forming mats in mud; culms 2-7 (-12) cm. long, 0.1-0.4 mm. thick, usually 
sulcate or irregularly flattened; sheaths extremely short and inconspicuous, hyaline, 
often slightly reddish; spikeiets ovoid to cylindric, 2-9 mm. long, stramineous, 

384 




Fig. 196: a-e, Eleocharis caribaea: a, habit, X ^^; b and c, two views of sheath. 
X 5; d, spikelet, X 5; e, achene, X 40. f-i, Eleocharis atropurpurea: f, habit, X %; g, 
sheath, X 8; h, spikelet, X 5; i, achene, X 40. (Courtesy of R. K. Godfrey). 






f 1 







Fig. 197: a-d, Elcocharis Baldwinii: a. habit. X i^.; b, sheath. X 12; c. spikeict. X 8; 
d, achene, X 35. e-i, Elcocharis parvula: c. habit, X V-; f, sheath. X 12; g and h, 
spikelets, showing variation, about X 25; i, achene, X 40. (Courtesy of R. K. Godfrey). 



medially chartaceous, laterally membranous and marginally hyaline; bristles usually 
reduced and essentially obsolete in our plants, most of which are of the var. 
anachaeta (Torr.) Svens.; stamens 3; style 3-branched; achenial body ovoid to 
obovoid, trigonous, 0.8-1 mm. long, passing through shades of gray to fuscous or 
black at maturity, smooth, usually somewhat shiny; tubercle conic-trigonous, 
much narrower than the body of the achene and confluent with it, scarcely 
differentiable except under high magnification, 0.1-0.2 mm. long. Scirpus nanus 
Spreng. (non-Poir.), E. membranacea (Buckl.) Gilly. 

In mud and shallow water of lakes, ponds and stream banks, occasionally in 
salt marshes, infrequent to locally abundant, essentially throughout Tex., in Okla. 
(Kay, Stephens, Grady, San Miguel and Garvin cos.), N.M. (Chaves and Eddy 
cos.) and Ariz. (Navajo Co.), spring-fall; var. parvula is widespread in Eur., 
N. Afr., the Near East and N.A.; var. anachaeta is scattered in w. N.A. 

20. Eleocharis pauciflora (Lightf.) Link. 

Perennial with filiform rhizomes bearing small leafy tubers; culms capillary, 
grooved, erect, 7-14 cm. tall or sometimes 40 cm. tall, usually less than 1 mm. 
thick, not proliferous; basal leaf sheaths 2-3 cm. long, truncate; spikelets 4-7 
mm. long, ovate 2- to 7-flowered; scales lanceolate, acuminate, purplish-brown 
bristles 2 to 6, shorter than to as long as or longer than the achene; style trifid; 
achene trigonous, the surface finely reticulate, yellowish-brown, about 2 mm. long; 
tubercle a subulate beak merging into the dark base of the style. 

Boggy or otherwise wet places at high elevations in the mts., tolerant of salt 
and alkali, Ariz. (Apache and Coconino cos.), circumboreal, e. to 111. and N. J. 

21. Eleocharis rostellata (Torr.) Torr. Fig. 198. 

Tufted perennial with short often erect rhizomes to 5 mm. thick; culms 25-80 
(-150) cm. long, flattened (1-1.4 mm. thick in the broader dimension), on each 
side usually 3- or 4-costate, wiry, tough, erect or the more elongate ones arching 
and taking root as the spikelet touches the ground, thus stoloniform; sheaths 
firm, apically slightly oblique; spikelets lanceolate, acute, 8-17 mm. long, 2.5-4.5 
mm. thick, with 12 to 30 flowers; scales ovate, 3-3.5 mm. long, the upper ones 
more acute than the lower, medially rigid and with a strong stramineous midrib, 
passing laterally through chartaceous to membranous texture and in color through 
shades of brown to pale-brown or stramineous marginally; bristles firm, regularly 
serrulate, pale-brown, about equaling the tubercle; style 3-branched; achene body 
obscurely trigonous or turgidly plano-convex, obovoid, brownish, shiny, 1.5-1.7 
mm. long, apically narrowed and merging with the tubercle; tubercle oblong or 
stelelike, 0.7-1 mm. long, 0.3-0.4 mm. thick basally (at attachment but narrower 
most of the length). 

Mud in upland areas, springs, alkaline marshes and seeping wet meadows, in 
Okla. (Texas Co.), frequent in Tex. Plains Country, infrequent on Edwards 
Plateau, N. M. (Otero, DeBaca, San Juan, Valencia, Sandoval, Eddy and Grant 
COS.) and Ariz. (Coconino, Yavapai, Graham, Cochise and Santa Cruz cos.), 
summer-fall; N.S. and Me. to Fla., inland in Ont. to N.J., Mich., Wise, 111., Kan., 
Okla., Tex., Coah., B.C. to Wyo., Ut., Cahf., N.M.; Berm, Cuba, Hisp., n. Mex., 
mts. of Ecu. and Arg. 

22. Eleocharis tortilis (Link) Schult. Fig. 199. 

Tufted perennial; rhizomes ascending, 2-3 mm. thick; culms 15-50 cm. long, 
0.5-1 mm. thick, usually flattened or irregularly 3-costate and -sided, often twisted, 
wiry, grayish to yellowish; sheaths grayish or yellowish, shortly oblique and acute 
or blunt, firm; spikelets ovoid to lance-ovoid or cylindric-ovoid, 6-14 mm long, 
of 13 to 38 flowers; scales ovate to suborbicular, about 3 mm. long, blunt, firm 
(subcartilaginous medially to chartaceous marginally), yellowish or grayish-strami- 

387 




Fig. 198: Eleoclioris rostellata: a, habit showing the wiry culms, some procumbent 
and rooting at the tips, X '.-,; b, mature obtusely trigonous achene with surface finely 
reticulate, the tubercle subulate and continuous with the apex of the achene, X 12; c, 
spikelet, X 4; d, flower, X 8; e, scale, X 8. (From Mason, Fig. 137). 





Fig. 199: Eleocharis tortilis: a, habit, X 1/2; b, sheath, X 5; c, spikelet, X 5; d, achene, 
X 20. (Courtesy of R. K. Godfrey; b, V.F.). 



neous, sometimes with a subterminal purplish splotch especially when immature; 
bristles several, brownish, often surpassing the achenial body; style 3-branched; 
achenial body broadly obovoid, 1.2-1.7 mm. long, obscurely trigonous, the sides 
convex, surficially pronouncedly large-cellular (the cell walls prominent), lustrous, 
olivaceous-brown or gray; tubercle pyramidal, 0.6-1 mm. long, usually acute, 
basally narrower than the body, truncately constricted to the very narrow attach- 
ment. 

Infrequent in moist or wet sandy soil and seepage areas in e. Tex., May-Nov.; 
coastal areas, N. Y. to Tex. 

23. Eleocharis Baldwinii (Torr.) Chapm. Fig. 197. 

Tufted annual; culms 6-20 cm. long, 0.1-0.25 mm. thick, ascending or often 
strongly recurved and stoloniform; sheaths mostly reddish, long-oblique, blunt, 
hyaline; cleistogamous few-flowered spikelets usually abundant at base of plant 
among the sheaths; ordinary spikelets mostly narrowly elliptic. 4-7 mm. long, of 
5 to 10 flowers, frequently proliferating when the recurved culm (stolon) touches 
the ground; scales pseudodistichous, the lowest linear and with a strong green 
midnerve, the others progressively broader toward the top of the spikelet, lance- 
elliptic, 3-4.5 mm. long, buffy to ferruginous-buff", membranous, strictly appressed, 
acute; bristles several, pallid, about equaling the achenial body or reduced; style 
3-branched; achenial body ovate, 0.7-0.8 mm. long, whitish-buffy to olive or 
brownish-olive, trigonous (angles distinct and sides nearly flat), smooth; tubercle 
pyramidal-trigonous, 0.2-0.3 mm. long, acute, constricted basally. 

In bogs and about pools, near Caddo Lake, La. (part of this lake extends into 
e. Tex.), summer-fall; N.C., Ga., Fla., La., (Tex.?). 

24. Eleocharis minima Kunth. Fig. 200. 

Tufted annual; culms 3-7 (-10) cm. long, about 0.1 mm. thick, extremely weak, 
often flexuous and recurved, quadrangulate-sulcate; sheaths dark-reddish, apically 
long-oblique, blunt, hyaline; reduced (cleistogamous?) spikelets often present at 
the base of the plant among the culms; ordinary spikelets 2-4 mm. long, ovoid, 5- 
to 10-flowered, usually blunt; scales ovate to narrowly ovate, blunt or shortly 
acute, 1.5-2 mm. long, brown and membranous (midrib paler), marginally hya- 
line; bristles about 5 to 7, whitish, about as long as the body of the achene; style 
3-branched; achenial body obovoid, 0.7-0.8 mm. long, sharply trigonous (the 3 
sides slightly convex), ripening through olive-whitish to pale-olive or even dark- 
olive-gray, often somewhat mottled, darker near the angles and the ends, essen- 
tially smooth; tubercle sharply pyramidal-trigonous, 0.15-0.3 mm. long and broad, 
slightly constricted basally. 

Rare in mud and shallow water of lakes, ponds and slow-flowing streams, cypress 
swamps, in s.e. Tex. (Aransas and Jackson cos.), spring and fall; trop. Am. s. to 
s. Braz. and n. to Ga., Tex. and Calif. 

25. Eleocharis microcarpa Torr. Fig. 200. 

Tufted annual; culms 4-28 cm. long, (0.1-) 0.15-0.3 mm. thick, mostly erect 
or ascending (less commonly weak and somewhat flexuous). often quadrangulate- 
sulcate (at least when dry); sheaths short, stramineous or slightly tinged with pink 
basally, apically long-oblique, blunt and hyaline; spikelets never at the base of the 
plant, always terminal on elongate culms, ovoid, 2-5 mm. long, 8- to 15-flowered, 
often proliferous (sending out culms instead of flowers, usually from the axil of 
the lowest scale), the spikelet then slightly inclined; lowest scale differentiated, 
bractlike, sterile, lanceolate to linear, often a third to three fourths the entire 
length of the spikelet, consisting mostly of a prominent green midnerve with 
reduced membranous sides; other scales ovate, about 1.5 mm. long, blunt, the 

390 







Fig. 200: a-e, Eleocharis microcarpa: a, habit, X V2', b. sheath, X 12; c, spikelet, 
X 10; d, scale, X 20; e, achene, about X 50. f-i, Eleocharis minima: f, habit, X V-y, g, 
sheath, X 16; h, spikelet, X 8; i, achene, about X 35. (Courtesy of R. K. Godfrey). 





iT'^" ^vVn ^'f'''^'"'"'' ^'!^'d^- a, habit. X Vy, b. sheath, X 12; c, spikelet, X 5; d, 
achene, X 40. (Courtesy of R. K. Godfrey). 



median distal portion purplish (midrib paler) and membranous, the median proxi- 
mal portion whitish, the margins white-hyaline; bristles somewhat variable, in our 
specimens much reduced or usually absent; styles 3-branched; achenial body 0.5- 
0.6 mm. long, obovoid, trigonous (angles not very prominent, sides convex), 
pearly-white, lustrous, smooth; tubercle 0.05-0.1 (-0.15) mm. long, depressed- 
pyramidal, buffy-white, slightly constricted basally. E. Brittonii Small, E. LundelUi 
Svens. 

On sandy loams, in mud and shallow water of ponds and streams, and depres- 
sions in savannahs, frequent in s.e. Tex., infrequent in e. Tex., spring-fall; coastal 
areas, Conn, and N.J. to Tex.; also Tenn. and Ind. 

26. Eleocharis albida Torr. Fig. 201. 

Rhizomatous perennial; rhizomes extensive, 1-2 mm. thick, orangish-brown; 
culms tufted at intervals along the rhizome, 5-30 cm. long, about 1 mm. thick, 
erect, essentially terete, stramineous or basally slightly pinkish; sheaths apically 
truncate or shortly oblique and firm but membranous, basally often pinkish to 
red; spikelets ovoid to ovoid-cylindric, 5-16 mm. long, of 30 to 90 flowers, rarely 
proliferating; scales broadly ovate, subcartilaginous medially, firm-membranous 
marginally, stramineous, shiny; bristles 5 to 8, when mature reddish-brown, some 
often surpassing the achenial body, others half as long; style 3-branched; achenial 
body broadly obovoid, 0.8-1 mm. long, trigonous (the 2 inner angles sharper and 
more definite than the abaxial one, the faces only slightly convex), maturing 
through shades of olive-whitish to brownish-olive and finally to a rich dark- 
chocolate-brown, lustrous; tubercle varying from conic to globular, 0.15-0.3 
mm. long, paler than the body at maturity, constricted basally. 

Frequent in moist perhaps brackish sand and on lake margin and in water, in 
coastal parts of Rio Grande Plains and s.e. Tex., spring-summer; coastal areas, 
Md. to Mex.; Berm, 

27. Eleocharis elongata Chapm. Fig. 202. 

Culms very slender, usually less than 1 mm. wide, elongate, 5-8 dm. long, often 
floating on the surface of the water, flattened or obscurely angled; roots fibrous; 
stolons abundant, brown or straw-colored, elongate, with culms rising from the 
nodes; spikelets 1-1.5 cm. long, about 2 mm. wide, acute; style 3-branched; 
stamens 3; scales linear, obtuse, 3.5 mm. long, striate, greenish, conspicuously 
broadened with brown just within the hyaline margin; achenes 1.5 mm. long 
including the style base, triangular, light-green, obovate (the inner face broadest, 
with about 12 rows of coarse transversely linear cells), abruptly narrowed at the 
summit to a short acute neck one-fourth the width of the achene from which 
rises the short acute deep-brown style base; bristles 6 or 7, equalling the achene, 
greenish, prominently toothed. 

In quiet water of lakes and ponds in Tex. (Hardin Co.); Fla. to Tex. 

28. Eleocharis tenuis (Willd.) Schult. var. verrucosa (Svens.) Svens. 

Rhizomatous perennial; rhizomes 1-2 mm. thick, scaly-fibrous, castaneous- 
fuscous; culms tufted at intervals along the rhizomes, 15-50 cm. long, 0.2-0.3 
mm. thick, weakly ascending, 4- or 5-sulcate or simply angled; sheaths basally 
purplish-red, apically firm, truncate to very slightly oblique, usually with a 
minute mucro; spikelets oblong or narrowly ovoid to lance-ovoid, 3-9 mm. long, 
of 20 to 40 flowers; scales ovate to obovate, obtuse, about 2 mm. long, with a 
greenish or stramineous midrib and firm castaneous to purplish-black sides, 
marginally very narrowly scarious; bristles 2 or 3, promptly deciduous, very short; 
styles 3-branched; achenial body broadly obovoid to suborbicular, distinctly 
trigonous, 0.6-0.8 mm. long, ripening through shades of ivory to greenish-olive, 
surficially minutely but pronouncedly warty or pitted in vertical lines; tubercle 

393 




6 ■ ■/ J- tret 1 

».:ivj- C--C.-S. ^ - 
'-<--*, t. E' «-■ *■ 




Fig. 202: Eleocharis elongata: a, habit, X Va b, sheath, X 12; c, spikelet, X 5; d, 
achene, X 35. (Courtesy of R. K. Godfrey). 




Fig. 203: Eleocharis Parishii: a, scale, X 10; b, toothed truncate leaf sheath, X 6; 
c and d, habit, showing average and small plants, the slender erect fascicled culms and 
the creeping rhizomes, X %; e, flower, X 10; f, trigonous obovoid achene, the surface 
faintly reticulate, the tubercle conic and the subtending bristles longer than the achene, 
X 20; g, spikelet, lineae-lanceolate, acute, X 6. (From Mason, Fig. 138). 



strongly depressed-pyramidal, 0.1-0.2 mm. long, slightly constricted basally. 

Infrequent in moist or wet sand, wet forested areas, along ditches and in wet 
mud along sloughs, in Okla. (Payne Co.) and e. Tex., rare in s.e. Tex., spring; 
temp. e. N.A., w. to 111., Mo., Okla. and Tex. (the var. verrucosa in the w. part 
of that distribution area). 

29. Eleocharis cylindrica Buckl. 

Rhizomatous perennial; rhizomes slender (1-2 mm. thick); culms 15-30 cm. 
long, 0.4-0.5 mm. thick, about 4-sulcate and -angled, erect; sheaths faintly 
reddish-brown basally. apically firm, truncate or very slightly oblique, mucronate; 
spikelets linear-cylindric, 8-17 mm. long, 2-2.5 mm. thick, acute, of 50 to 60 
flowers; scales about 2 mm. long, ovate, acute, medially thin-membranous, brown 
(the midnerve pale), marginally white-hyaline, slightly convex abaxially; bristles 
pale-brown, 0.05-0.1 mm. long, extremely inconspicuous; style 3-branched; 
achenial body 0.6-0.8 (-1 ) mm. long, obovoid, strongly and obviously trigonous 
(the sides slightly concave, the angles prominent but not sharp), ripening through 
canary-yellow to golden-brown or dark-brown, essentially smooth and satiny, 
apically conspicuously and abruptly narrowed to a short cylindric pedestal; 
tubercle depressed-pyramidal, about 0.1 mm. long and about as wide or pyramidal 
and about 0.3 mm. long. 

Rare, probably in shallow water or calcareous mud, in Tex. Plains Country 
(Lubbock Co.) and Trans-Pecos (Presidio Co.), June-July; endemic, to be sought 
in N.M. and Chih. 

30. Eleocharis Parishii Britt. Fig. 203. 

Perennial (or sometimes annual?) with slender creeping reddish rhizomes; 
culms slender, striate, erect, 1-3 dm. tall, in fascicles or tufted; leaf sheaths 
reddish-brown at base, usually becoming straw-colored at the obliquely truncate 
apex, usually with a minute tooth; spikelets linear-lanceolate, acute, 10-15 mm. 
long, many-flowered; scales ovate-oblong, acute to obtuse, chestnut-brown or 
dark-brown, with a short hyaline tip; bristles 6 or 7, as long as to longer or 
shorter than the achene; style trifid; achene trigonous, ellipsoid or obovoid, yellow 
to light-brown, smooth or faintly reticulate under magnification; tubercle short- 
subulate to conic. 

Moist soil, wet meadows or rooted in shallow water to form small mats in 
N.M. (Grant and Valencia cos.) and Ariz, (widely distributed); Ore. to N.M., 
Ariz., Calif, and n. Mex. 

31. Eleocharis tnontevidensis Kunth. Fig. 204. 

Rhizomatous perennial; rhizomes extensive, 1-2 (-2.5) mm. thick, usually dark- 
reddish; culms 1-5 dm. long, 0.4-1 mm. thick, erect, rather soft, sometimes slightly 
compressed, in pressed specimens often irregularly sulcate and showing incom- 
plete and weak septa; sheaths basally dark-reddish, apically quite firm, truncate 
or only very slightly oblique and weakly mucronate; spikelets very variable in 
shape, from globular to cylindric or ovoid to elliptic, apically blunt, 3-14 mm. long, 
with 24 to 70 (to 110) flowers; scales mostly oblong to oblong-ovate. 2-3 mm. 
long, obtuse to slightly emarginate, the median portion membranous and brownish 
to atrocastaneous (with or without a paler midnerve), marginally scarious, often 
somewhat convex abaxially, concave adaxially (this true even before the achenes 
mature, so the spikelets appear filled out soon after anthesis); bristles 4 to 6. some 
of them usually equaling the tubercle; style 3-branched; achenial body obovoid 
to pyriform-obovoid. (0.8-) 0.9-1.1 (-1.2) mm. long, turgid, obscurely trigonous, 
ripening through shades of yellow to golden-brown or even dark-brown, punctuate- 
reticulatc surficially (varying from as rough as in E. compressa to nearly smooth 
as in the plant called E. Palmeri), lustrous; tubercle precisely to irregularly conic, 

396 






Fig. 204. Eleocharis montevidensis: a, habit, X i/^; b, sheath, X 10; c, spikelet, X 5; 
d, achene, X 40. (Courtesy of R. K. Godfrey). 






V ^n\?^'- ^'"'''S'J,'"'!' f^ff°^- a. habit, X 1,^; b, sheath, X 5; c, spikelet. X 5; d, achene, 
X 20. (Courtesy of R. k. Godfrey). 



(0.1-) 0.2-0.3 (-0.4) mm. long. E. arenicola Torr., E. Palmed Svens. 

In moist soil, in shallow water of streams and ponds and in wet granitic sands, 
in Okla. (Roger Mills, Alfalfa, Grady, Johnston and Bryan cos.), essentially 
throughout Tex. (rare in extreme e. and extreme w.), N. M. (Sandoval Co.) and 
Ariz. (Coconino, Yavapai, Pima, Cochise and Santa Cruz cos.), spring (-summer); 
cen. Mex. n. to Ore., Ida., N.M., Okla., the Gulf States and S.C; also s. Braz., 
Urug. and Arg. 

32. Eleocharis fallax Weath. Fig. 205. 

Perennial much like E. macrostachya but styles 2- or 3-branched, the achenes 
averaging smaller (body 1.2-1.7 mm. long and tubercle 0.2-0.5 mm. long) and the 
body more distinctly and regularly punctate (much as in E. montevidensis) . 

Rare in (brackish?) mud, s.e. Tex. (collected once in Matagorda Co.), summer 
(?); coastwise, Mass. to Tex.; Cuba. 

33. Eleocharis austrotexana M. C. Johnst. 

Densely tufted perennial (probably with short slender matted reddish rhizomes); 
culms 30-45 cm. long, erect, 0.8-1.1 mm. thick, essentially terete, with 12 to 15 
minute striae in dried specimens and very weak but complete transverse septa 2-3 
mm. apart (otherwise hollow); sheaths 2-5 cm. long, tight, mostly reddish, apically 
quite firm, truncate or only very slightly oblique and with a seta or mucro to 
1 mm. long; spikelets lanceolate, acuminate, acute, 8-13 mm. long, of about 50 
to 70 flowers; scales ovate and acute to broadly lanceolate, about 2 mm. long, 
medially buffy-brown (midnerve paler) and membranous, marginally hyaline, whit- 
ish; bristles about 6 to 8, pale-brown, translucent, inconspicuous, persistent, un- 
equal, the longer ones about equaling the achenial body; style 3-branched; achenial 
body obovoid-pyriform, 0.7-0.9 mm. long, obscurely trigonous (the 2 inner angles 
definite, though not sharp, the abaxial one obscure), ripening through shades of 
yellow to golden-brown, surficially nearly smooth, slightly lustrous (under very 
high magnification punctulate-reticulate); tubercle depressed-pyramidal, about 0.2 
mm. long and broad, slightly constricted basally. 

Rare in Rio Grande Plains and s.e. Tex., Apr.; endemic. 

34. Eleocharis compressa Sulliv. 

Rhizomatous perennial; rhizomes 2-4 (-6) mm. thick, usually short and forking, 
forming dense thick mats; culms tufted along the rhizome, 9-20 cm. long, erect, 
strongly compressed, 0.6-1 mm. broad in the flat dimension, several-striate on each 
side; sheaths usually reddish basally, apically firm and truncate or only very 
slightly oblique, with a mucro; spikelets ovoid to narrowly ovoid, 5-12 mm. long, 
with 20 to 40 flowers; scales broadly lanceolate, the lower medial portion chestnut- 
brown or chestnut-fuscous (the mid-nerve somewhat paler), the margins and the 
long-attenuate sometimes bifid (split) apex translucent-scarious; bristles 1 to 5, 
promptly deciduous, very short; style 3-branched; achenial body broadly obovoid, 
turgid, obscurely trigonous, about 1 mm. long, ripening through yellow to a golden- 
brown, surficially granular-roughened or reticulate (rougher than in the following 
species but not as rough as in E. tenuis); tubercle 0.1-0.2 mm. long, depressed- 
to globose-conic, usually slightly constructed basally. E. elliptica Kunth var. com- 
pressa (Sulliv.) Drapalik & Mohlenbrock. 

Rare in loamy usually moist soil and in shallow water of ponds and streams 
in Okla. (Latimer Co.) and in e. Tex. (San Augustine Co.), spring; most of n.e. 
U.S.; also Ont., Sask., Ga., Okla. and Tex. 

35. Eleocharis acutisquamata Buckl. 

Rhizomatous perennial; rhizomes 2-4 (-6) mm. thick, usually short and forking, 
forming dense thick mats; culms tufted along the rhizomes, 8-20 (-28) cm. long, 

399 



0.3-0.8 mm. thick, slightly compressed or usually merely irregularly several-angled; 
sheaths usually slightly pinkish basally, apically firm and truncate or only very 
slightly oblique, not mucronate; spikelets narrowly oblong or cylindric to narrowly 
elliptic, usually with a blunt point, 3-11 mm. long, of 24 to 44 flowers; scales 
broadly lanceolate, the lower medial portion brown (the midnerve slightly paler), 
the margin and the long-attenuate sometimes bifid (split) apex translucent-scarious; 
bristles several, extremely short and promptly deciduous; style 3-branched; 
achenial body broadly obovoid-pyriform, turgid, obscurely trigonous, 0.9-1.2 mm. 
long, ripening through yellow to golden-brown, surficially very minutely granu- 
lar-roughened and obscurely reticulate; tubercle conic to essentially globular, 0.1 
mm. long (rarely to 0.2 mm.), basally constricted. Probably conspecific with 
E. compressa. 

In calcareous loamy (usually slightly moist) soil, in water of ponds and lake 
margins, seepage areas, in Okla. {Waterfall) and on Tex. Edwards Plateau and 
n.-cen. Tex., infrequent s. to s.e. Tex. (Refugio Co.) and in e. Plains Country, 
spring. 

6. Bulbostylis Kunth 

Essentially glabrous perennial forming tight swards of limited extent or less 
commonly annual herbs; culms closely tufted, 4-30 cm. long, 0.2-0.6 mm. thick, 
wiry, erect; leaves setaceous, about half as high as and even thinner than the 
culm; primary brach setaceous, often appearing as a continuation of the culm or 
spreading, 3-22 mm. long; other bracts setaceous, much-reduced; inflorescence 
umbelliform or cymose, simple or compound, 5-40 mm. long or occasionally re- 
duced to a glomerule or even rarely a single spikelet; spikelets lance-cylindric, 
dark-brown, of 7 to 25 perfect flowers; scales spirally imbricate, ovate, obtuse 
to acute or rarely retuse, dark-brown, 1-2 mm. long, strongly keeled (the keel 
paler), occasionally slightly gibbous, glabrous to strigose or puberulent, marginally 
smooth to slightly fimbriate; perianth bristles absent; style 3-branched, the base 
enlarged and persistent as a tubercle 0.5-1 mm. long, differentiated in texture 
and color from the achenial body; achenial body obovoid or usually obpyramidal, 
strongly triquetrous, 0.7-0.9 mm. long, maturing through shades of white to 
pale-buffy-white or grayish, with papillae or transverse ridges. Stenophyllus Raf. 
(a rejected name). Many authors, with much justification, include Bulbostylis in 
Fimhristylis. 

About 100 species in warm regions. 

1. Achenes papillose, maturing yellowish or grayish; cyne typically compound 
1. B. ciliatifolia. 

1. Achenes transversely ridged or rugose; cyme simple (2) 

2(1). Strong perennial; achene with about 20 minute but (under a lens!) con- 
spicuous and pronounced transverse rugae on each face, maturing 
to a grayish color 2. B. juncoides. 

2. Annual; achenes with about 10 indistinct transverse ridges on each face, 

maturing to a bufl'y-white (3) 

3(2). Spikelets 2 or more in each inflorescence, at the apex of the culms, not 
sessile in axils of basal leaves; leave sheaths usually sparsely villous, 
at least at the summit; achenes all alike 3. B. capillaris. 

3. Spikelets usually solitary at the apex of the culms and others sessile in axils 

of leaves; leaf sheaths glabrous; middle achenes of basal spikelets 
larger than those of the culms 4. C. Funckii. 

1. Biilbosfylis ciliatifolia (Ell.) Fern. Fig. 206. 

Characters given in the generic description and the key. 

Uncommon in periodically wet sandy soil of open woods and hillsides in Okla. 

400 




Fig. 206: Bulbostylis ciliati folia: a, habit, X Vz; b, achene, X 30. (Courtesy of R. K. 
Godfrey). 



(Waterfall) and e. and s.e. Tex., summer-fall; from Va. s. to Fla., w. to Tex. 
and Okla. 

2. Bulbostylis juncoides (Vahl) Kukenth. Fig. 207. 
Characters given in the generic description and the key. 

Locally frequent in rock crevices and seepy areas in Chisos and Davis Mts. in 
the Tex. Trans-Pecos, rare in granite area of Edwards Plateau, w. to Ariz. 
(Yavapai, Cochise, Santa Cruz and Pima cos.), summer; Tex. and Ariz., s.e. to 
Guat.; Hisp., Bol. to Urug. and Arg. 

Our plants are referable to the var. ampliceps Kukenth. (which name is 
probably not the earliest applicable one in the varietal rank). 

3. Bulbostylis capillaris (L.) Clarke. 

Characters given in the generic description and the key. Fimbristylis capillaris 
(L.) Gray. 

Infrequent in sandy soil and in crevices of granitelike rocks which decompose 
to sandy soil, seepage areas, in Okla. (Johnston Co.), e., s.e., and n.-cen. Tex. 
and Edwards Plateau (Central Mineral Region), rare in Tex. Trans-Pecos, N.M. 
(Dona Ana, Grant and Socorro cos.) and Ariz. (Yavapai, Greenlee, Gila, 
Cochise, Santa Cruz and Pima cos.), spring-summer; widespread in warm-temp. 
N.A., s. to Calif., Ariz., N.M., Okla. and the Gulf States; Tarn., Cuba, reported 
in Chih. 

4. Bulbostylis Funckii (Steud.) C. B. Clarke. 

Similar to B. capillaris except that the spikelets are usually solitary, apical and 
sessile in the axils of the leaves with achenes 1-1.2 mm. long, and that the leaf 
sheaths are glabrous. 

Wet soil, in canyons, N.M. (Socorro Co.), Ariz. (Mohave, Gila, Cochise and 
Pima COS.) and Chih., s. to cen. S.A. and the W.I. 

7. Fimbristylis Vahl 

Perennial or annual, the culms solitary or in tufts, or variously rhizomatous, 
rigid or lax, leafy toward the base; leaves filiform to narrowly or broadly linear, 
glabrous to pubescent, flat or involute, ligulate or eligulate, the sheaths closed 
or partly open at maturity of the leaf; spikelets lanceolate or oblong to ovoid or 
round in outline, terete or somewhat flattened or angled, either solitary and 
terminal on the scapes or in simple or compound umbelliform systems involving 
pedunculate and sessile spikelets of cymules, the whole inflorescence as well as 
the cymules composing it often subtended by a leafy involucre; fertile scales 
glabrous or variously pubescent, subdistichous to more often spirally arranged, 
deciduous, all but the lowermost fertile; florets perfect; perianth absent (the flower 
produced on a short pedicel joint which usually disarticulates with the achene); 
stamens one to three; anthers oblong, basifixed, sometimes apiculate, the two 
thecae at maturity longitudinally and laterally dehiscing; style 2- or 3-branched, 
the unbranched portion flattened and fimbriate for at least a portion of its length 
or (more rarely) subterete or angled, the style base either flattened or swollen 
but in any event not persistent at the summit of the achene; achene lenticular 
or trigonous; surface of achene smoothish, cancellate or warty, usually made up 
of isodiametric or horizontally arranged rectangular cells, these either concave 
or protuberant. 

Over 200 described species, in a variety of habitats in warm temperate to 
tropical regions of the world. 

(Adapted from Robert Krai in Sida 4, No. 2. 1971.) 

I. Style -l-branched (2) 
1. Style 2-branched (3) 

402 





Fig. 207: a and b, Bulbostylis juncoides: a, habit, X i.^; b, achene, X 10. c-e, 
Scleria Muhlenbergia: c, habit, X Vo; d, achene, X 12; e, hypogynium from below, 
X 12. (a-c, V. F.; d and e. Courtesy of R. K. Godfrey). 



2(1). Achene trigonous, the surfaces smooth or warty; ligule of short hairs 
present 1. F. autumnalis. 

2. Achene not trigonous or only obscurely so, obovoid, the surfaces usually warty; 

ligule absent 2. F. miliacea. 

3(1). Ligule of short hairs present (this characteristic is most noticeable in those 
entities that have broadly linear flattened leaf blades but is difficult 
to detect in those extremes that have very involute narrow leaf 
blades) (4) 

3. Ligule absent (9) 

4(3). A system of slender pale or reddish rhizomes present; robust perennials 
with tall wandlike culms (5) 

4. Rhizomes absent or (if present) thickened and composed of stout contiguous 

culm-bases; perennial or annual species (7) 

5(4). Outer surface of spikelet scales uniformly pubescent; spikelets elliptic- 
oblong, the apices of the bracts acutish and with the midrib ex- 
serted as a prominent mucro; backs of leaf bases often pubescent 
3. F. thermalis. 

5. Outer surface of spikelet scales glabrous or puberulent apically; spikelets 

ovoid to lance-ovoid, rarely oblong, the apices of the bracts rounded 
with the midrib somewhat exserted; backs of the leaf bases seldom 
pubescent (6) 

6(5). Fertile scales puberulent toward the tip; scapes usually flattened, often 
scabrous-edged distally; edges of leaves (especially toward the tip) 
scabrid; achene finely but definitely reticulate; in upper edges of 
salt marshes, dune swales or fresh marshes on the Coastal Plain 
4. F. caroliniana. 

6. Fertile scales usually smooth; scapes more slender, terete or broadly oval in 

cross section and smooth distally; edges of leaves usually not 
scabrid; achene smoothish or with longitudinal rows of shallow 
isodiametric pits; moist or wet prairies, river sloughs, marshes and 
springy places in west Texas 11. F. puberula var. interior. 

7(4). Face (one side) of achene smoothish or with many (15 or more) longi- 
tudinal row of shallow pits or cells (thus finely striate) 

5. F. tomentosa. 

7. Face (one side) of achene more closely reticulate, usually with 12 or less 

longitudinal rows of horizontally oriented rectangular cells (8) 

8(7). Perennial with spreading hard pale-green leaves; achenes lacking warts 

6. F. dichotoma. 

8. Annual with spreading or ascending leaves; achenes with warts 

7. F. annua. 

9(3). Low often densely tufted weedy annual; leaf blades linear-filiform 

8. F. Vahlii. 

9. Taller more robust wider-leaved perennials (10) 

10(9). Plants densely cespitose; bases of leaves hard, leathery, usually very dark- 
brown or castaneous, often quite lustrous, deeply set in substrate; 
common to brackish coastal habitats 9. F. castanea. 

10. Plants in small tufts or culms solitary; bases of leaves thickened and hard 

or culm bases bulbous but in any case more shallow-set in sub- 
strate; either with stout contracted rhizomes or with fasciculate 
clusters of narrow orange-brown rhizomes; from sandy acid pine- 
land savannahs or oak barrens to heavy prairie soils but not in 
brackish coastal habitats (1 1) 

404 



11(10). Base of culms bulbous, often joined together into a stout knotty rhi- 
zome; old leaf bases often persisting as shreddy remnants; outer 

surface of fertile scales usually with some puberulcnce 

10. F. puberula. 

11. Base of culms rarely bulbous, usually producing fascicles of slender orangish 
rhizomes; old leaf bases not persisting as shreddy remnants; outer 

surface of fertile scales seldom with any puberulence 

11. F. puberula var. interior. 

1. Fimbristylis autumnalis (L.) R. & S. Fig. 208. 

Cespitose annual, usually 5-20 cm. tall; leaves glabrous, spreading, subdis- 
tichous, from half as long as the culms to equaling the culms; blades linear (to 
4 mm. broad), flat, the backs with numerous raised veins, the margin a pale 
cartilaginous ciliate-scabrid border; sheaths broader, keeled, with a broad scarious 
tan entire margin, joining the blade at an acute angle or truncate; ligule present 
as a line of short pale hairs; scapes flat, similar to the leaf blades, the edges often 
harsh; longest involucral bract with blade similar to that of the leaves, seemingly 
a continuation of the scape, shorter to longer than the inflorescence; spikelets 
linear-oblong to lanceolate, usually 3-7 mm. long, pale- to dark-brown, in an 
open to densely paniculate system of cymes, the primary rays usually ascending; 
fertile scales ovate-lanceolate, usually keeled, entire, the midrib excurrent as a 
mucro; stamens usually 2, rarely 1, 0.2-0.3 mm. long; style 3-branched, much 
longer than the achene, trigonous at the base, subterete above toward the branches, 
entirely smooth; achene trigonous-obovoid, apiculate, about 1 mm. long, pale- 
brown, the surface smooth to quite verrucose. 

Moist to wet sands, peats, silts or clays, primarily of disturbed sunny ground, 
in marshes, and mud and water at edge of streams, ponds and lakes, in Okla. 
(Mayes, Ottawa, Love, Mcintosh, LeFlore, McCurtain and Sequoyah cos.) and 
most of Tex.; various provinces of e. N.A.; Carib., I., Mex. and C.A.; also Old 
and New World trop. 

2. Fimbristylis miliacea (L.) Vahl. Fig. 209. 

Cespitose annual to 5 dm. tall (rarely to 1 m.); leaves equitant, distichous, from 
one half the length of the plant to nearly as long, rigid, smooth, flabellately spread- 
ing, tapering evenly from broad clasping sheaths into the blade, thence continuing 
to taper into a slender tip, the numerous veins raised and evenly spaced; margin 
of the blade narrow, pale, cartilaginous, antrorsely ciliate-scabrid, the margin of the 
sheath somewhat broader, scarious and entire; sheaths keeled, often bladeless; 
ligule not evident; scapes slender but rigid, flattened or somewhat angled in cross 
section toward the base, more flattened distally but often with a double margin 
along each edge; spikelets subglobose to ovoid or short-cylindrical, 2-4 mm. long, 
on flattened scabrous pedicels in a compound loose to congested system of cymes; 
longest involucral bract usually shorter than the inflorescence; fertile scales ovate, 
pale- to (usually) dark-brown, smooth, the apex obtuse to rounded or emarginate, 
the margin entire, the midrib paler by contrast or greenish and rarely excurrent; 
stamens 1 or 2, the anthers less than 1 mm. long; style 3-branched, the unbranched 
portion not much longer than the achene, subterete below, more flattened and 
fimbriate above toward the branches; achene obovoid (usually narrowly so), apic- 
ulate, about 1 mm. long, pale-brown, reticulate, the cells narrowly rectangular and 
horizontally oriented in 4 to 6 rows on a face, the longitudinal ribs usually more 
prominent and usually verrucose. 

Sandy peat, peat-muck and silt of open areas such as savannahs, pond, lake or 
river shores, cult, areas (particularly rice fields), in the U.S. from N.C. s. in the 
Coastal Plain into peninsular Fla., w. along the Gulf Coast into Tex.; throughout 
the Carib. I., Mex. and C.A. 

405 




Fig. 208: a and h, Fimhrixlylis castanea: a, habit, X %; b, achene, X 13. c and d, 
Fimhristylis auiumnalis: c, habit, X i^; d, achene, X 15. e, Fimhristylis dichotoma: 
e, achene, X 16. f, Fimhristylis caroliniana: i, achene, X 16. (Courtesy of R. K. 
Godfrey). 



3. Fimbristylis thermalis Wats. 

Rhizomatous perennial, solitary or in small tufts, to about 1.5 m. tall; leaves 
one third to one half the length of the scapes; blades linear, 1-4 mm. broad, flat 
to somewhat involute, glabrous or with some pubescence toward the sheath and 
apex on lower surface, upper surface just above ligule usually puberulent, veins 
numerous and prominent on the lower surface, the pale marginal vein or veins 
cartilaginous and ciliate-scabrid; sheath much broader, clasping, indurate, usually 
with some pubescence, stramineous to dull-brown, with a broad and scarious 
margin that is usually entire and converging to the blade at an acute angle; ligule 
of short pale hairs present; spikelets oblong-cylindric to lance ovoid, 1-2 cm. 
long, pale dull-brown, 1 to many in a closed to rather open paniculate system of 
cymes; longest bract of the inflorescence shorter than the inflorescence; scapes 
rather rigid, about the width of the leaves, glabrous, many-ridged, subterete below, 
progressively flattened toward the inflorescence, the edges of the flattened portion 
scabrous; fertile scales ovate, subentire, pale dull-brown, dorsally uniformly puberu- 
lent, the midrib by contrast paler and exserted as a prominent cusp; stamens 3, 
the anthers about 2 mm. long; style branches 2, the style flattened and fimbriate 
from the base to above the point of branching; achene lenticular-obovoid, about 
1.5 mm. long, dark lustrous-brown, finely reticulate, the individual foveae hori- 
zontally rectangular and arranged in numerous vertical lines; joint of achene short, 
persistent on fruit. 

On usually highly mineralized sandy substrate of marshes and about hot springs 
in Ariz. (Coconino Co.); s. Calif., Nev., Ut. and Ariz., s. to B. Calif, and Coah. 

4. Fimbristylis caroliniana (Lam.) Fern. Fig. 208. 

Rhizomatous perennial, 1.5 (-2) m. tall; culrns solitary or in small tufts, the 
bases rather shallowly set in the substrate; leaves subdistichous, usually spreading, 
about half as long as the scapes; blades firm, linear, 2.5 (-7) mm. wide, the sur- 
faces smooth or in some cases pubescent near the ligule or the upper face, the 
backs with several raised nerves, the pale margin hyaline and scabrid; leaf-sheath 
broader, clasping, firm, pale- to dark-brown, glabrous to sparsely pubescent, with 
a wide stramineous to tan or reddish-brown scarious margin (this gradually or 
abruptly passing into the blade and often ciliate at this point); ligule of appressed 
hairs, usually complete; scapes about the width of the leaf blade, glabrous, many- 
ribbed, subterete toward the base, usually flattened toward the apex (in which 
case the edges scabrid); longest bract of the involucre much shorter than the in- 
florescence to but slightly exceeding it, the back glabrous to puberulent, the margin 
harsh; spikelets ellipsoidal to lance-ovoid or oblong, 5-15 mm. long, blunt to acute, 
pale-dull-brown to reddish-brown, a few to many in a compound umbellate sys- 
tem of cymes, the edges of the peduncles scabrid; fertile bracts ovate, glabrous or 
puberulent on the backs toward the apex, the margin entire, the surface marked 
by a thick usually paler area of midrib (this sometimes excurrent as a short 
mucro); stamens 3, the apex of the flattened filaments narrowed, the anthers 
about 3 mm. long; style 2-branched, flat, fimbriate from near the base to slightly 
beyond the point of branching; achene lenticular-obovoid, about 1 mm. long, 
pale- to deep-brown, often lustrous, finely reticulate with the reticule composed 
of several fine rows of foveae or horizontally oriented rectangular cells; pedicel 
joint very short, usually persistent. 

Brackish, alkaline or mildly acid sands or sandy peats of beaches, dune 
swales, lake shores, roadside ditches, more rarely savannahs or flatwoods. Coastal 
Plain from N.J. s. into the Fla. Keys and w. along the Gulf Coast to Tab.; Cuba. 

5. Fimbristylis tomentosa Vahl. 

Cespitose annual to 7.5 dm. tall; leaves from half as long to nearly the length 

407 



of the mature culms; blades linear, 2-4 (-5) mm. broad, usually flat but some- 
times slightly involute, spreading to ascending, the surfaces pubescent, the backs 
with several prominent raised nerves, the margin evident as a pale cartilaginous 
narrow border which is ciliate-scabrid; leaf sheath broad, usually tomentose, 
with a wide brownish subscarious margin (this long-ciliate and truncate above at 
juncture with blade); ligule present as horizontal line of short pale hairs; scapes 
rather rigid, subterete basally, usually flattened or oval in cross section just below 
inflorescence, smooth or variously pubescent; spikelets at maturity a rich-reddish- 
brown, lance-ovoid, 4-6 mm. long, acute, usually many in a rather dense pani- 
culate system of cymes the primary branches of which are usually ascending, 
pubescent (spikelets solitary in depauperate specimens); longest involucral bract 
exceeding inflorescence, leaflifle in its vestiture, always with a prominently hairy 
sheath; fertile bracts ovate, at maturity glabrous, reddish-brown except for a 
paler often greenish area of midrib (this usually exserted as a short cusp, backs 
of the midrib of lowermost scales often with some hairs); anthers 2, 0.7-1 mm. 
long; style 2-branched, flattened, the edges fimbriate from near the base to the 
base of the branches; achene obovoid, slightly apiculate, including the pedicel 
1.7-2 mm. long, lenticular, finely foveate (pitted) with the pits arranged in many 
vertical rows, sometimes slightly umbonate, at maturity a dark- to pale-brown 
except for the pale margin; pedicel joint persistent, to 0.5 mm. long. 

Moist to wet sands, silts or clays of disturbed habitats such as pond or river 
banks, roadside ditches, canals or agricultural grounds, Coastal Plain from N.C. 
s. to n. Fla. and w. into Tex. 

6. Fimbristylis dichotoma (L.) Vahl. Fig. 208. 

Tufted perennial to 5 dm. tall or more; leaves from half as long to nearly 
the length of the culms; blades linear. 2-5 mm. broad, flat to somewhat involute, 
often glaucous and spreading, usually glabrous or rarely the lower surface pubes- 
cent, with several prominent nerves, the margin evident as a pale cartilaginous 
border that is ciliate-scabrid; sheaths broad, usually appressed-pubescent, with 
a wide tan or reddish-brown subscarious margin that is ciliate and subtnmcate 
apically; ligule present as a horizontal line of short hairs; scapes rigid, subterete 
basally, usually flattened or oval in cross section just below the inflorescence, 
the flattened edges usually scabrid; longest involucral bract usually longer than 
the inflorescence, the blade similar to a leaf blade, the sheathing base sometimes 
pubescent and ciliate; spikelets drab to brownish or reddish-brown, usually lance- 
ovoid to oblong, 4-8 mm. long, acute, in an open to dense simple or compound 
umbellate system of cymes (spikelets solitary in depauperate specimens); fertile 
bracts broadly oblong to ovate, acute to obtuse at apex, the margin entire, the 
surface smooth and pale- to dark-brown except for a paler often greenish midrib 
that terminates at the apex or is excurrent as a short cusp; anthers 1 or 2, about 
1 mm. long; style 2-branched, flattened with the edges fimbriate toward the 
point of branching; achene lenticular-obovoid, sometimes fairly tumid, about 1 
mm. long or slightly longer, apiculate. white to brownish, striate-reticulafe. the 
cells rectangular, shallowly concave, horizontally arranged in (5) 10 to 12 longi- 
tudinally rows. 

In moist or wet sunny savannahs, fields, grasslands and along roadsides in s.e. 
Tex.; Old World species fast becoming a weed throughout the lower Coastal 
Plain of s.e. U.S. 

7. Fiiiibristyli.s annua (All.) R & S. Fig. 210. 

Cespitosc, decumbent to ascending or erect annual, to 5 dm. tall (usually much 
lower); leaves from half as long to nearly the length of the mature culms; blades 
usually narrowly linear, glabrous to tomentose, 1-2 (-4) mm. wide, the backs 

408 




Fig. 209: a and b, Fimbristylis miliacea: a, habit, X V3; b, achene, X 20. c and d. 
Fimbristylis puberula: c, habit, X %; d, achene, X 16. (Courtesy of R. K. Godfrey). 




Fig. 210: Fimbristylis annua: a, habit, X 1/2; b, spikelet, X 5; c, spikelet with lower 
achenes fallen, X 5; d, scale, X 5; e, achene, X 5. (V. F.). 



with several prominent raised nerves, the often pale margin cartilaginous and 
usually ciliate-scabrid; sheaths broad, smooth or pubescent, with a wide sub- 
scarious margin that is smooth or pubescent, pale brown, toward its apex ciliate 
and truncate or acute; ligule present as a horizontal line of short hairs; scapes 
lax to rigid, ascending or erect, subterete basally, flattened or subterete above 
at juncture with inflorescence; longest involucral bract similar to leaves in its 
width and indument, shorter or longer than the inflorescence, the sheathing base 
smooth or hirsute; spikelets lance-ovoid or oblong, 3-8 mm. long, acute, greenish 
to tan or brown to a dark-reddish-brown, in a few- to many-spikeletted simple 
or compound umbellate system of cymes (spikelets solitary in depauperate speci- 
mens); fertile bracts broadly oblong to ovate, the apex acute to obtuse, the margin 
entire, the surface smooth, the paler midrib seldom excurrent; anthers 1 or 
rarely 2, about 1 mm. long; style 2-branched, flattened, ahe edges fimbriate from 
the base to the branches or entire basally; achene lenticular, ovoid or obovoid 
and quite tumid, about 1 mm. long, apiculate, white to brownish, often irides- 
cent, striate-reticulate, the rectangular cells shallowly concave and horizontally 
arranged in from 5 to 12 longitudinal rows per side, the longitudinal ribs more 
conspicuous than the horizontal; surface of achene often verrucose, the warts 
forming either along the longitudinal ribs or over entire cells. F. Baldwiniana 

410 



I 



(Schult.) Torr., F. alamosa Fern. 

On a variety of moist sunny substrates such as savannahs, roadsides, grass- 
lands and disturbed or cultivated areas, in mud on edge of ponds and streams, in 
Okla. (Adair and Mayes cos.) and mostly s.e. Tex.; in temp, to trop. climates 
of both hemispheres. 

8. Fhnbristylis Vahlii (Lam.) Link. Fig. 211. 

Cespitose low annual, the culms to 1.5 dm. tall (usually much lower); leaves 
one third as long as the scape to equaling or exceeding it; blades linear-filiform, 
spreading-recurved, less than 1 mm. broad, somewhat involute, the backs with 
several prominent raised veins, often with small stiff ascending hairs, the margin 
somewhat thickened and similarly hairy; leaf sheath broad, stramineous or pale- 
brown, usually smooth or with a scattering of small hairs, the margin scarious, 
entire, passing gradually into the blade; ligule absent; scapes stiffly ascending, 
wiry, slightly broader than the leaves, glabrous, many-ribbed, subterete; spikelets 
lance-ovoid to linear-ellipsoidal or oblong, 5-10 mm. long, usually acute, pale- 
greenish-brown, 3 to 8 in a dense terminal cluster that are subtended by several 
leaflike involucral bracts (these always exceeding the inflorescence and usually 
at least the length of the basal leaves); fertile bracts ovate-lanceolate or oblong- 
lanceolate, glabrous, stramineous or pale-green, the midrib conspicuous, dark- 
green and pK>inted beyond the scale as a short erect or slightly recurved mucro; 
stamen 1, the anther less than 0.5 mm. long; style 2-branched, much longer than 
the achene, subterete, the base swollen, the surface smooth or papillate from about 
the midpoint to the point of branching; achene obovoid, tumid, 0.5-0.7 mm. long, 
pale, sometimes slightly iridescent, reticulate, the individual rectangular cells ar- 
ranged horizontally in 5 to 7 vertical rows on a side. 

Fine sands, silts or clays, usually alluvial or shoreline situations, often on areas 
of disturbed bottomland, in mud and wet sand on edge of ponds and lakes, in 
Okla. (LeFlore, Pittsburg, Stephens, Mcintosh and McCurtain cos.), e. and s. 
Tex. and Ariz. {Kearney & Peebles); S. C. s. to n. Fla., w. to Tex.; scattered lo- 
calities in inland states; in w. U.S., Calif, and Ariz.; Mex. and C.A. 

9. Fimbristylis castanea (Michx.) Vahl. Fig. 208. 

Densely cespitose perennial to 1.5 (-2) m. tall, the bases of the plants castaneous, 
deep-set in substratum, the outer leaves of a tuft and the older leaves persistent as 
imbricated scales; leaves from one third the length of the culms to nearly as long; 
blades usually very narrowly linear (rarely to 2 or 3 mm. broad), ascending, thick 
(often semicircular in cross section), most frequently involute, smooth (particu- 
larly toward the base), the nerves on the back numerous and indistinct but the 
marginal nerve or nerves ciliate-scabrid with ascending stout-based hairs; sheathing 
portion of the leaf broad (broadening gradually toward the base), pale-brown to 
dark-brown or very deep-lustrous-reddish-brown, thick and rigid, the broad margin 
thin or even scarious, entire except for the truncate or rounded ciliate apex; ligule 
of hairs either absent or incomplete but a color change evident on the upper 
surface of the leaf at the collar; scapes slender, wandlike, as wide as the blades 
or somewhat wider, many-ribbed, terete toward the base of the plant, subterete to 
oval or elliptical in cross section upwardly; longest bract of the involucre usually 
shorter than the inflorescence or about the length of the inflorescence (rarely 
longer), the blade somewhat flattened, ciliate-scabrid; spikelets usually ovoid or 
lance-ovoid, very rarely cylindrical, 5-10 mm. long, rarely longer, the mature 
ones usually pale- to dark-brown, dull, in a dense to open ascending or spreading 
umbellate compound system of cymes; fertile bracts broadly ovate, smooth, brown, 
usually dull, the margin entire or becoming arose with age, the apex rounded; 
veins of the mid-portion of the scale obscure or visible as faint pale lines that 

411 





1©/ 






Fig. 211: Fimhristylis Vahlii: a, habit, X 1; b, habit, X 2; c, scale, X 50; d, achene, 
X 50. (Courtesy of R. K. Godfrey). 



converge apically to form a short mucro; stamens 2 or 3, the anthers about 2 mm. 
long; style 2-branched, flattened, fimbriate from the base to the point of branch- 
ing; achene lenticular-obovoid or obpyriform, 1.5-2 mm. long, reddish-brown or 
dark-brown, often lustrous, scalariform-foveate or reticulate, the individual cells 
almost isodiametric or horizontally rectangular and usually arranged in numerous 
fine vertical rows. 

Moist sands or muck of coastal marshes, dune swales or estuary banks (rarely 
alkaline situations inland), L.I., s. along the Atl. Coast into the Fla. Keys, along 
the Gulf Coast s. and w. into Tarn, and the Yuc. Peninsula; Bah. I., Cuba. 

10. Fimbristylis pubenila (Michx.) Vahl. Fig. 209. 

Perennial to 1 m. tall; culms solitary or in small tufts, the bases often hard, 
knotty and jointed together into short thick rhizomes on which the old leaf bases 
often persist as shreddy remnants; leaves from one third as long to nearly equaling 
the culms; blades narrowly linear, usually involute at least toward the base, about 
1 mm. wide, the backs with several raised nerves, smooth to variously pubescent, 
the upper surface smooth or variously pubescent, the pale margin cartilaginous 
and ciliate-scabrid (this most noticeable toward the blade-base and -apex); sheathes 
hard, thick, fibrous, pale- to dark-brown, the broad margin scarious and entire ex- 
cept for long cilia at apex; ligule inconspicuous, incomplete or absent; longest bract 
of inflorescence erect, the blade flattened, usually much-surpassed by the inflores- 
cence; spikelets lance-ovoid to ovoid or ellipsoidal, 5-10 mm. long, reddish-brown, 
in a usually few-flowered compact to open system of pedunculate cymules or a 
simple umbel-like cyme; fertile scales ovate to obovate or even reniform, reddish 
brown to dull-brown or flavescent, the backs rounded, the scarious rounded margin 
entire and ciliate or somewhat lacerate, the inconspicuous nerves flavescent to 
pale-brown or sometimes the central ones slightly raised, greenish and slightly 
excurrent as a short mucro; outer surface of at least the lower scales puberulent 
at least toward the apex; stamens 3, the anthers 2-2.5 mm. long; style 2-branched, 
flattened, the edges usually fimbriate from about the midpoint to the base of the 
style branches; achene lenticular-obovoid, about 1 mm. long, rather flat to stme- 
what tumid, sometimes umbonate, flavescent to dark-brown, the surface distinctly 
to faintly reticulate, the rectangular cells usually arranged in several longitudinal 
lines (1 1 to 20 on a face) in a few cases with very many longitudinal lines with 
the cells isodiametric, the longitudinal lines prominently to slightly raised. 

Sands, sandy peats or clays of savannahs, edge of ponds, open pinelands, upper 
edges of grass-sedge bogs, meadows and prairies, throughout the Atl. and Gulf 
Coastal Plain from L.I. s. into peninsular Fla. and w. to Tex. nearly to the Mex. 
border; scattered from the cen. Piedmont to its southwest edge; scattered in the 
interior highlands and of frequent occurrence in the moist meadows and prairies 
of the cen. lowlands, particularly along the Great Lakes on the Pleistocene shores 
and w. into the tall and mid-grass prairies of Tex., Okla., Kan. and Neb.; Can. 

11. Fimbristylis puberula var. interior (Britt.) Krai. 

As var. puberula but plant base less bulbous and producing dense clusters of 
short slender twisted pale-reddish-brown rhizomes; foliage pale-green, sometimes 
appearing glaucous; blade margins distantly to approximately ciliate-scabrid; ligule 
inconspicuous or present at a narrow line of short ascending hairs; longest involu- 
cral bract usually longer than the inflorescence; spikelets ovoid to cylindrical or 
ellipsoidal, 5-10 mm. long, stramineous to reddish-brown, the backs of the scales 
usually smooth, the central nerve of at least the lower scales excurrent as a definite 
terete mucro; achene with several prominent to rather obscure longitudinal ridges 
that are interconnected with finer horizontal lines, hence the surface composed of 
longitudinal rows of roughly isodiametric shallowly concave cells. 

413 




Fig. 212: a-d, Hemicarpha micrantha var. micrantha: a, habit, X %; b, inflores- 
cence, X 2; c, scale, X 36; d, achene, X 46. e-g, Hemicarpha micrantha var. aristulata: 
e, inflorescence, X 2; f, scale, X 36; g, achene, X 36. (Courtesy of R. K. Godfrey). 



Sandy sloughs in prairie provinces, particularly in w. Kan. and Neb. but ex- 
tending s. into w. Tex. and southw. to Ariz. 

8. Hemicarpha Nees & Arn. 

A genus of a few species (perhaps as many as 6) of warm regions. Hemicarpha 
is closely related to Cyperus subgenus Kyllinga but the inflorescence and flowers 
are much-reduced. Some authors include Hemicarpha in Scirpus but this has 
very little merit. 

1. Hemicarpha micrantha (Vahl) Britt. Fig. 212. 

Essentially glabrous densely tufted annuals; culms 1-22 cm. long, 0.2-0.6 mm. 
thick, essentially leafless; leaves usually 2 per culm at its base; upper sheath 
purplish or brownish, its blade linear to setaceous; lower sheath much-reduced, 
its blade absent; lower bract often appearing as a continuation of the culm, 7-37 
mm. long; 1 or 2 other much-reduced bracts present; inflorescence a glomerule of 
2 (rarely 3) sessile heads or head solitary; heads broadly ovoid, 2-8 mm. long, 
of 60 to 140 uniflorus spikelets in tight spirals; scale solitary per spikelet,e()?t,d 
of 60 to 140 uniflorus spikelets arranged in tight spirals; scale solitary per spikelet, 
abaxial, ovate to lanceolate, 0.8-2.3 mm. long, the midrib conspicuous often as 
a keel in the lower part and a mucro or awn apically, the sides membranous, 
convex; "perianth" (actually the wings of the reduced spikelet axis) of a single 
hyaline adaxial scale, often split and torn by or adhering to the achene, very 
inconspicuous; stamens 1 or 2; styles 2-branched; achene oblong, nearly terete 
or elliptic in transection, 0.5-0.8 mm. long, very minutely apiculate, surficially 
miscroscopically papillate. Scirpus micranthus Vahl. 

The species is widespread in wet or moist soils in warm temp, and trop. areas 
of Am. We have 3 varieties as follows: 

Var. micrantha. "Perianth" scale much shorter than the achene, often bifid 
or reduced or absent. Infrequent or rare in moist or wet soils along streams, s, 
part of e. Tex., Rio Grande Plains and Trans-Pecos; widespread in trop. Am., 
Calif., Wash.. Gulf States and n.e. U.S. 

Var. aristulata Cov. "Perianth" scale equaling or surpassing the achene and 
often cupped around it distally and adaxially, with no definite vascular tissue 
(use magnification of 40 diameters); awn of floral scale two thirds as long as 
to a little longer than the body of the scale. Infrequent in moist soil, throughout 
most of Tex. to Ariz.; Neb. and Wyo., s. to Tex., N.M. and Ariz. 

Var. Drummondii (Nees) Friedl. "Perianth" scale equaling or surpassing the 
achene and often cupped around it distally and adaxially, with 3 to 5 vascular 
strands; mucro of floral scales less than two thirds as long as the body of the 
scale. In Okla. (Comanche Co.), e. and n.-cen. Tex., N. M. (Bernalillo Co.) 
and Ariz. (Pima Co.); from Mo. and Neb. s. and s.w. to Tex., N.M. and Ariz.; 
intergrading with the last variety. 

Var. minor (Schrad.) Friedl. Mucro shorter than body of glume; "perianth" 
scale shorter than the achene and usually more or less bifid. Ariz. (Cochise an'd 
Pima COS.). 

9. Cyperus L. Flatsedge 

Herbs, usually with culms leafy near the base, often subscapose; inflorescence 
terminal, an umbel-like aggregation of primary peduncles (each subtended by a 
bract, usually) bearing spikes or heads of spikelets or the longer of the peduncles 
each bearing smaller umbel-like aggregations of secondary peduncles (with or with- 
out bractlets) each bearing spikes or head of spikelets or the whole inflorescence 
contracted into a dense flowering mass with the true form obliterated; spikelets 
usually borne in several rows on the spike or head axis, with a minute bract basally 
and either with several to many fertile scales distichously arranged or else reduced 

415 



to a single fertile scale plus one or more sterile scales above, when several scales 
present the spikelet usually discernibly laterally compressed (i.e., as if the 2 margins 
of the folded scale were pushed toward each other and the scale creased at the 
usually keel-like median portion, the breadth of the spikelets then measured from 
keel to keel of alternating scales and the thickness from side to side of the same 
folded scale), the spikelet axis either disarticulating at the top of each internode 
or only at its base or often completely persistent, each internode of the spikelet 
axis often with 2 thin "wings" on each side of the flower (the decurrent lower 
margins of the next superjacent scale); scales usually folded, either persistent or 
deciduous; perianth absent; stamens 1 to 3; styles 2- or 3-branched; achenes 
lenticular or trigonous, often stipitate and/ or apiculate, jointed with the style 
usually at the very top of the achene, the achenial body there with or without a 
minute apiculus but the latter (if present) of the same color and texture as the 
main part of the achene. 

With upwards of 900 species in warm regions, Cyperus, a vast, difficult genus, 
is often made more confusing by a very unsatisfactory and arbitrary segregation 
of smaller "genera," such as Mariscus Vahl, Pycreus Beauv., Kyllinga Rottb. 

1. Achene lenticular, biconvex or concavo-convex (2) 

1. Achene trigonous or vaguely so, occasionally appearing nearly terete but 

definitely not biconvex nor concavo-convex (9) 

2(1). Achene dorsiventrally compressed, i.e., with one of the sides appressed to 
the spikelet axis, the other appressed to the inner surface of the 
scale, the latter not keeled 1. C laevigatus. 

2. Achene laterally compressed, i.e., with one angle next to the spikelet axis and 

the 2 slightly convex sides parallel with the 2 sides of the scale, the 
scale being folded and creased at the keel-like median (3) 

3(2). Each spikelet with only 2 scales and only one achene (4) 

3. Each spikelet with 6 to 60 scales, usually several of them fertile (6) 

4(3). Stamens solitary; plants rhizomatous, the culms rising at intervals of 3-10 
mm 2. C. brevifolius 

4. Stamens paired; culms densely tufted or plants mat-forming (5) 

5(4). Densely tufted with a culm density of 4 to 20 per square cm. in the tufts; 
culms about 0.7 mm. thick basally; inflorescence 3-8 mm. long; 
bracts with translucent corners at the very base; spikelets 2-2.5 mm. 
long, 0.7-0.8 mm. broad, sordid-whitish or very pale-brownish; 
lower (fertile) scale 1.7-2.4 mm. long; achene elliptic, 0.9-1.1 mm. 
long (not including the apiculus), 0.5-0.6 mm. broad, ripening to 
a very dark brown 3 C. tenuifoliits. 

5. Culm density in the mat 1 to 4 per square cm.; culms 0.8-1.8 mm. thick 

basally; inflorescence 7-14 mm. long; bracts without translucent 
corners; spikelets 2.3-3 mm. long, 1.2-1.3 mm. broad, buffy-white 
to white; lower (fertile) scale 2.2-2.9 mm. long; achene obovate, 
1-1.4 mm. long (not including the apiculus), 0.75-0.9 mm. broad, 
ripening black 4. C. sesquiflorus. 

6(3). Spikelets borne in lax spikes 12-40 mm. long and 12-23 mm. thick; scales 
with broad white-hyaline margins markedly contrasting with the 
brownish sides; achenes 1.2-1.5 mm. long 5. C. alhomarginatiis. 

6. Spikelets borne in heads or glomerules; scales with thin but not hyaline nor 

white margins; achenes mostly less than 1.2 mm. long (7) 

7(6). The lower part of the edges of the internodal niches of the spikelet axis 
with minute persistent wings which become narrowed and join 

abaxlally forming a minute cup at the base of the achene 

6. C. polystachyos. 

416 



7. The edges of the internodal niches essentially wingless (8) 

8(7). Achenial surface with rectangular-linear cells oriented vertically in hori- 
zontal rows, these rows marked off by horizontal wavy usually dis- 
colored sutures 7. C. flavescens. 

8. Achenial surface with vertical rows of minute essentially isodiametric usually 

somewhat hexagonal cells; spikelets 7-12 mm. long; scales about 
2 mm. long 8. C. niger. 

9(1). The spikelet axis at maturity disarticulating at the base of each internode 
(just above each node), thus breaking into units consisting of a 
scale, the next lowest internode and the attached wings and clasped 
achene; internodes postanthetically on the sterile side becoming 

thickened and assuming a white cartilaginous texture 

9. C. odoratus. 

9. The spikelet axis either persistent as a unit or else deciduous as a unit, not 

disarticulating spontaneously at maturity (10) 

10(9). Culms stiffly erect with complete septa at intervals of 5-50 mm 

10. C. articulatus 

10. Culms non-septate (11) 

11(10). Each of the 5 to 8 extremely unequal primary peduncles with an irregu- 
lar panicle of several spikes each with a number of ascending spike- 
lets; the total inflorescence with 100 to 600 spikelets; scales when 
spread out nearly orbicular, about 1.5 mm. long; spikelet axes 
wingless 11. C Ida. 

11. Each primary peduncle either reduced or bearing a head or spike or a 

glomerule, or bearing several short secondary peduncles but never 
an irregular panicle; scales usually considerably longer than broad 
or if nearly as long as broad then longer than 1.5 mm. (12) 

12(1 1). Stamens 1 or 2; spikelet axis wingless or essentially so (13) 

12. Stamens 3; spikelet axis winged or wingless (22) 

13(12). Scales less than 1 mm. long, rounded or truncate at apex, the lateral 

nerves indistinct, hyaline-margined, 3-nerved, caducous, annual 

12. C. difformis. 

13. Scales 1 mm. or longer, acuminate at apex, the lateral nerves prominent (14) 

14(13). Scales with 7 to 9 strong evenly distributed nerves and a wholly keel-like 
median portion, terminating in a spreading recurved awn; annual, 
reddish-brown at base 13. C. aristatus. 

14. Scales with 3 or 5 nerves and these sometimes obscure and concentrated in 

the median portion, the tip mostly either incurved or straight (15) 

15(14). Scales 3-nerved, acuminate to cuspidate or aristate (16) 

15. Scales 5-nerved, (3-nerved if culm has retrorse projections) apex blunt, 

rounded or acute (18) 

16(15). Bracts 3 to 6, scarcely if at all surpassing the inflorescence; rays up to 
10; spikelets to 18 mm. long, reddish-brown, digitate-radiate; scales 
aristate 14. C. amabilis var. macrostachyos. 

16. Bracts 2 to 4, much-surpassing the inflorescence; rays up to 5; spikelets not 

more than 10 mm. long, in dense heads, white to pale-brown; scales 
mucronate to acuminate (17) 

17(16). Matted perennial with a tuberiferous rhizome, to 3 cm. long; culm much- 
thickened and fibrous-coated at the base; leaf sheaths nearly black; 
bracts more or less reflexed; inflorescence contracted into a single 
head; achene nearly black 15. C seslerioides. 

417 



17. Annual or biennial; rhizome wanting; stems scarcely thickened or fibrous- 

coated basally; leaf sheaths often reddish-brown or purplish-brown 
at base; bracts erect or ascending; inflorescence with 2 to 5 rays, 

rarely a single head; achenes brown or purplish-brown 

16. C acuminatus. 

18(15). Achenes only 0.7-0.8 mm. long; culms with scattered microscopic re- 
trorse projections like shark's teeth 17. C. surinamensis. 

18. Achenes 0.9-1.5 mm. long; culms either smooth or with antrorse or hori- 

zontal projections (19) 

19(18). Culms 5-12 mm. thick basally, apically 3-8 mm. thick and with micro- 
scopic antrorse projections like shark's teeth; scales 2-2.4 mm. long, 
when spread out 1.2-1.5 mm. broad at the broadest point (just 
below the middle) 18. C. virens. 

19. Culms 0.7-5 mm. thick basally, apically 0.4-2.7 mm. thick, either smooth or 

with microscopic knobs (very rarely with antrorse projections in 
C. pseudovegetus); scales 1.3-1.9 mm. long (20) 

20(19). Scales with the dorsal basal flat portion or groove continuing a third to 
half the total length of a scale and 0.3-0.5 mm. broad; scales when 
spread out 1.5-1.9 mm. broad near the base and tapering all the 
way to the apex; achene 1.3-1.5 mm. long, 0.5-0.6 mm. thick, 
maturing to a nearly black color 19. C. ochraceus. 

20. Scales with the dorsal basal flat portion or groove continuing only a fifth to 

a third the total length and only 0.1-0.2 (-0.3) mm. broad; scales 
when spread out 0.6-1.2 mm. broad at the broadest (near the 
middle or shortly below); achene 0.9-1.3 mm. long, 0.2-0.45 mm. 
thick, maturing to a brownish color (21) 

21(20). Scales essentially linear for most of the length, only 0.6-0.7 mm. broad 
and (as folded in place) the whole scale incurved-falcate; achene 
linear, 0.2-0.3 mm. thick 20. C. pseudovegetus. 

21. Scales ovate, reddish with greenish keels, 0.8-1.1 mm. broad at the broadest 

point, as folded in place the lower part of the keel incurved but 
the upper part straight , 21. C. reflexus. 

22(12). Most leaves reduced to mere bladeless sheaths or occasionally the upper- 
most sheaths with short blades very rarely to 10 cm. long (23) 

22. Even the lower leaves with well-developed blades (26) 

23(22). Inflorescence (not including bracts) 1-2 cm. long 22. C. phaeolepis. 

23. Inflorescence (not including bracts) 3-35 cm. long (24) 

24(23). Bracts usually 2, 1 of them 0.3 to 1 (to 2) times as long as the inflores- 
cence 23. C Haspan. 

24. Bracts 10 to 25, often much-surpassing the inflorescence (25) 

25(24). Internodes of spikelet axes with deciduous wings about 1 mm. long and 
0.2-0.3 mm. broad 24. C. giganteus. 

25. Spikelet axes wingless : 25. C. alternifoUus. 

26(22). Achene 0.4-0.7 mm. long, 0.4-0.5 mm. thick, subglobose, white; bracts 
usually only 2 in number 23. C. Haspan. 

26. Achene 0.7-3 mm. long, usually considerably longer than thick; bracts 3 to 

13 (27) 

27(26). Scales 1.3-2 mm. long; achenes 0.8-1 mm. long, 0.3-0.6 mm. thick, 
unequally trigonous; spikelet axis with readily deciduous wings, 
0.2-0.3 mm. broad; spikclets only 1 mm. broad, much-compressed, 
borne 15 to 70 together in spikes (28) 

418 



27. Scales (at least the fertile ones) 2.3-5.5 mm. long; spikelet axis either wing- 

less or with more or less persistent wings; spikelets variously borne 
but if only 1 mm. broad then not much-compressed (29) 

28(27). Internodes of spikes to 0.5 mm. long; scales 1.3-1.5 mm. long 

26. C erythrorhizos. 

28. Internodes of spikes 0.6-2 mm. long; scales 1.5-2 mm. long.. 27. C. digitatus. 

29(27). Achene 0.25-0.3 mm. thick 28. C. onerosus. 

29. Achene 0.4-1.2 mm thick (30) 

30(29). Achene 1-1.3 mm. long (31) 

30. Achene 1.3-3 mm. long, much longer than thick (32) 

31(30). Achene 1-1.3 mm. long, nearly as thick as long, pale or brown; spikelets 
much-compressed; scales 3-3.5 mm. long, acuminate, the keel 

grayish-white, the broad margins pale and hyaline 

29. C. compressus. 

31. Achene 1-1.2 mm. long, about half as thick, nearly black; scales 2-3 mm. 

long, obtuse, the keel green, the sides reddish-brown 

30. C. Parishii. 

32(30). Spikelet axis internodes essentially wingless, occasionally with wings to 
0.2 mm. broad (33) 

32. Spikelet axis internodes with wings 0.3-1.2 mm. broad (35) 

33(32). Nonviscid perennial, tufted and usually with extensive knotty subrhizo- 
matous bases; secondary peduncles absent; leaves neither spongy 
nor septate basally; inflorescence a single dense sessile head 1-3 
cm. thick with 15 to 55 spikelets 31. C filiculmis. 

33. Viscid tufted perennials with culms 3-7 mm. thick, the longer peduncles in 

most inflorescences with secondary peduncles each bearing a head 
similar to those of the shorter primary peduncles; leaves spongy at 
base, when dried their incomplete septa visible, the leaf apexes 
involute (34) 

34(33). Spikelets grayish-ochraceous turning grayish-brown; achene thickest 
(0.7-0.8 mm.) near the apex, long-tapered to the base, 1.4-1.8 
mm. long, only slightly apiculate 32. C. elegans. 

34. Spikelets grayish-yellow becoming rich-golden-brown; achene nearly cylin- 

drical or very slightly thickened in the upper part, long-tapered 
below, the main part 1.5 mm. long and 0.5 mm. thick but also with 
the persistent style base (or very large apiculus) adding almost 
1 mm. to the length 33. C. oxylepis. 

35(32). Rhizomatous perennials; spikelets with 6 to 40 eventually deciduous 
scales; spikelet axes persistent on the axis of the cluster or spike (36) 

35. Tufted perennials (occasionally with knotty subrhizomatous bases in C. 

huarmensis) ; spikelets with 2 to 8 scales (up to 20 in C. strigosus) 
and these persistent (deciduous in some specimens of C. strigosus) ; 
spikelet axis deciduous (more or less so in C. strigosus) (38) 

36(35). Bracts 3 or 4, about equaling the inflorescence; inflorescence with 20 to 
65 spikelets altogether, usually even the longer primary peduncles 
bearing a simple cluster or spike of spikelets just as do the shorter 
peduncles; each cluster or spike with 3 to 9 spikelets; wings of 

spikelet axis 2-3 mm. long; achenes 0.9-1 mm. thick 

34. C rotundus. 

36. Bracts 5 to 13, usually much-surpassing the inflorescence; inflorescence with 

70 to 350 spikelets altogether; the longer primary peduncles usually 
with several nearly sessile clusters or spikes of spikelets; each cluster 
or spike with 10 to 50 spikelets; wings of spikelet axis 1-1.5 mm. 
long; achenes 0.4-0.8 mm. thick (37) 

419 



37(36). Culms (60-) 75-110 cm. tall; bracts 9 to 13; primary peduncles 9 to 

13; spikelets reddish-brown; achenes 0.4—0.5 mm. thick 

35. C. setigerus. 

37. Culms 15-50 (-65) cm. tall; bracts 5 to 10; primary peduncles 5 to 10; 

spikelets brown, buffy-brown or golden-brown; achenes 0.6-0.8 
mm. thick 36. C. esculentus. 

38(35). Achenes mostly 0.3 to 0.5 times as long as the scales; spikelets 10-29 
mm. long, 1-2 mm. broad, usually less than half as thick as broad 
(39) 

38. Achenes mostly 0.6 to 0.8 times as long as the scales; spikelets 3.5-11 mm. 

long, 0.5-1 (-1.3) mm. broad, usually more than half as thick as 
broad (40) 

39(38). Blades 2-8 mm. broad; most inflorescences with the longer peduncles 
bearing a few short secondary ones; spikes 13-35 mm. long, 20-45 
mm. thick, thus usually thicker than long, with 20 to 70 spikelets 

1-2 mm. broad, golden- or tawny-brown, with 5 to 20 scales 

37. C. strigosus. 

39. Blades 1.5-5 mm. broad; secondary peduncle formation rare; spikes 20-40 

mm. long, 15-27 mm. thick, thus usually longer than thick, with 
14-45 spikelets 0.7-1.3 mm. broad, grayish-brown, with 3 to 6 
scales 38. C tenuis. 

40(38). Perennial from black knotty subrhizomatous bases; inflorescence only 
2-3 (-4) cm. long, of 3 to 6 essentially sessile spikes 10-25 mm. 
long and 7-10 mm. thick, with 40 to 80 three-scaled spikelets; only 
the lowest scale of each spikelet fertile and it enclosing the achene 
(1.5-2.1 mm. long, 0.8-1 mm. thick) 39. C. huarmensis. 

40. Tufted perennials; inflorescence (1-) 2-15 cm. long, of 1 to 14 usually 

peduncled heads or spikes 7-30 mm. long and 7-20 mm. thick, 
with 8 to 240 2- to 8-scaled spikelets in which only the terminal 
scale is sterile, the rest all fertile; achenes 0.5-0.8 mm. thick (41) 

41 (40) . Spikes lax, 10-30 mm. long, with 8 to 30 spikelets (42) 

41. Heads or spikes dense (the spikelets touching), 7-15 mm. long, with 25 to 

240 spikelets (43) 

42(41). Scales 2.2-2.5 mm. long, 1.5-2 mm. wide; achene olive-brown, minutely 
punctulate 40. C. Pringlei. 

42. Scales 2.5-3.5 mm. long, about 1 mm. wide; achene yellow-brown to browo., 

41. C hermaphroditiis. 

43(41). Achenes 1.8-2.2 mm. long; wings 1-2 mm. long; scales 1.2-2 mm. 
broad; spikelets 50 to 240 per head or spike, 0.5-1 mm. broad, with 
2 to 4 scales, straw-brown to dark-brown (to tawny-ochraceous).... 
42. C ovularis. 

43. Achenes 1.3-1.7 mm. long; wings 0.8-1.4 mm. long; scales 1-1.3 mm. broad; 

spikelets 25 to 70 per head, with 3 to 8 scales, greenish-brown to 
ochraceous-brown or olive 43. C globulosus. 

1. Cypenis lacvigatus L. Fig. 213. 

Densely tufted or mat-forming perennial; culms soft, 5-25 cm. long, 1-1.5 mm. 
thick; leaves reduced to basal sheaths with subulate or setaceous blades 3-30 mm. 
long; inflorescence 5-10 mm. long, of a single head of 4 to 8 spikelets; bracts 2, 
the longer one 2-8 cm. long, appearing as a continuation of the culm; spikelet 
straw-white or often white with atropurpurcous blotches medially, 4-7 mm. long, 
2-3 mm. broad, 0.7-1 mm. thick, with 8 to 30 scales, the axis persistent, essen- 
tially wingless, somewhat flattened; achene lenticular (often concavo-convex) with 
one of the flat sides against the flattened spikelet axis. 

420 




Fig. 213: Cyperus laevigatas: a, compressed spikelet, X 6; b, rachis, showing the 
persistent stamens and an achene with bifid style, X 20; c, habit, the culms arising singly 
from a horizontal rhizome, X %; d, obtuse scale, X 3; e and f, achenes, showing 
minutely reticulate surface, abaxial and adaxial views, X 12. (From Mason, Fig. 126). 




Fig. 214: Cyperus brevifolius: a, habit, X 1; b, scale, X 30; c, achene, X 25. 
(Courtesy of R. K. Godfrey). 

Infrequent in fresh or subsaline or gypseous mud in water on edge of canals 
and streams, and wet sandy flats, in the Tex. Trans-Pecos, and Ariz. (Pima. Yuma, 
Mohave and Cochise cos.), Feb.-Oct.; widely distributed in warm-temp, and trop. 
regions. 
2. Cyperus brevifolius (Rottb.) Hassk. Fig. 214. 

Perennial with creeping branching reddish-brown rhizomes to 20 cm. long and 
1-2 mm. thick; flowering culms rising from the rhizomes 3-10 mm. apart, 4-20 
(-38) cm. long. 0.4-1 mm. thick; leaves with sheaths 5-30 mm. long and mem- 
branous; flaccid blades 1-3 (-10) cm. long, 1-3 mm. broad, mostly much shorter 
than the culms except when the latter are dwarfed; inflorescence a single roundish 
seemingly simple congested head 4-6 mm. long and broad, with 38 to 100 spike- 
lets; bracts 3 (or 4), the longest one usually nearly vertical or ultimately reflexed, 
membranous, 15-120 mm. long, 1-2 mm. broad; spikelets each deciduous as a 
unit, 2-2.9 mm. long, 0.8-1.1 mm. broad, about 0.3 mm. thick, sordid- or buffy- 
whitish or very pale-brownish, with 2 scales, the lower one enclosing a fertile 
floret, the upper empty, the single short internode with very broad hyaline wings 
clasping the achene and continuous with the lower part of the higher scales; 
scales persistent (the lower one 1.9-2.4 mm. long), with green keels and translu- 
cent sides, each side with a couple of inconspicuous well-distributed nerves; 
stamens 1 (very rarely 2 in isolated spikelets, never many on the same head), at 
the abaxial angle of the achene; stigmas 2; achene lenticular with an adaxial angle 



422 



against the internode and abaxia! one at the keel of the lower scale, obovate or 
oblong-obovate, 1-1.2 mm. long (plus an apicule 0.05-0.1 mm. long), (0.6-) 
0.7-0.8 mm. broad, ripening to a rich-brown. Kyllinga brevifolia Rottb. 

Common weeds in moist or wettish loam, s.e. Tex., less common in e. Tex., 
rare in Edwards Plateau and Brownsville region, and Okla. {Waterfall), Apr-Nov.; 
widespread in warn regions. 

3. Cypenis tenuifolius (Steud.) Dandy. Fig. 215, 

Densely tufted fragrant annual (or short-lived perennial ?) with density of 
about 4 to 20 culms per square cm.; culms 1-21 cm. long, 0.5-0.7 mm. thick 
throughout; leaves with sheaths 8-45 mm. long and membranous; flaccid blades 
2-11 cm. long, 1-1.8 mm. broad, often more than two thirds as long as the culms; 
inflorescence a single roundish 3-lobed compound headlike mass 3-8 mm. long and 
5-6 mm. broad in the upper obtuse lobe, with 40 to 170 spikelets altogether; 
bracts 3 (or 4), ultimately spreading or slightly reflexed, flaccid, 2-10 cm. long, 
1-2 mm. broad, at the very base with broad translucent membranous corners; 
spikelets each deciduous as a unit, 2-2.5 mm. long, 0.7-0.8 mm. broad, about 0.3 
mm. thick, sordid-whitish or very pale-brownish, with 2 scales, the lower one 
enclosing a fertile floret, the upper empty, the single short internode with very 
broad hyaline wings clasping the achene and continuous with the lower part of 
the higher scale; scales persistent (the lower one 1.7-2.4 mm. long) with green 
keels and translucent sides, each side with a couple of inconspicuous well- 
distributed longitudinal nerves; stamens uniformly 2 at the abaxial angle of the 
achene; stigmas 2; achene lenticular, with the adaxial angle against the internode, 
the abaxial one at the keel of the lower scale, elliptic, 0.9-1.1 mm. long (plus an 
apicule 0.1 mm. long), 0.5-0.6 mm. broad, ripening to a very dark-brown. 
Kyllinga pumila Michx., Cyperus densicaespitosus Mattf. & KUkenth. 

Infrequent in moist loam, in marshes along streams, edge of ponds and other 
wet areas, e. Tex. (Bowie, Cass, Hardin and Polk cos.), rare in n.-cen. Tex. 
(Grayson Co.), and Okla. (McCurtain Co.), Sept.-Nov.; widespread in warmer 
moister parts of Am.; also Afr. and Madag. 

The name is incorrectly said by some writers to be illegitimate. 

4. Cyperus sesquiflorus (Torr.) Mattf. & Kiikenth. 

Annual (?) or usually perennial mat-formers, emitting a strong citronellalike 
odor when bruised, with a culm density of 1 to 4 flowering culms per square cm. 
in the mat; culms 5-30 cm. long, basally 0.8-1.8 mm. thick, apically 0.5-1 mm. 
thick; leaves essentially basal, with sheaths 1-2 (-3) cm. long and firm-mem- 
branous, ascending blades 3-12 cm. long and 2-3.5 (-5) mm. broad, mostly 
much shorter than the scapelike culms; inflorescence a single prolate few-lobed 
compound congested headlike mass 7-14 mm. long and 6-8 mm. broad in the 
upper cylindrical lobe, with 50 to 200 spikelets altogether; bracts 3 (or 4), ulti- 
mately slightly to strongly reflexed, firm-membranous, 2-8 cm. long, 1-3 mm. 
broad, at the very base discolored whitish-green but not hyaline at corners; spike- 
lets each deciduous as a unit, 2.3-3 mm. long, 1.2-1.3 mm. broad, about 0.4 min. 
thick, with 2 scales, buffy-white to white laterally, the lower scale enclosing a 
fertile floret, the upper one empty, the single short internode with very broad 
hyaline wings clasping the achene and continuous with the lower part of the 
higher scale; scales persistent (the lower one 2.2-2.9 mm. long) with green keels 
and buffy-white to white sides, each side with a couple of inconspicuous well- 
distributed longitudinal nerves; stamens uniformly 2 at the abaxial angle of the 
achene; stigmas 2; achene lenticular with the adaxial angle against the internode, 
the abaxial one at the keel of the lower scale, obovate, 1-1.4 mm. long, plus an 
apicule 0.05-0.15 mm. long, 0.75-0.9 mm. broad, ripening to jet-black. Kyllinga 

423 






Y\gl\5- Cy perns tenuifolius-. a, habit, X tl-; b, scale, X 30; c, achene, X 30. 
(Courtesy of R. K. Godfrey). 



;■■'- ' 




Fig. 216: a-d, Cyperus flavescens: a, habit, X V2; b, spikelet, X 5; c, scale, X 25; 
d, achene, X 25. e-h, Cyperus albomarginatus: e, habit, X V2; f, spikelet, X 7; g, scale, 
X 25; h, achene, X 25. (Courtesy of R. K. Godfrey). 



odor at a Vahl. 

Frequent in moist sandy loam, and on seepage slopes in e. Tex. (Angelina, 
Austin, Gonzales, Hardin, Lavaca and Newton cos.), June-Oct.; widespread in 
warm regions. 

5. Cyperus albomarglnatiis Mart. & Schrad. Fig. 216. 

Tufted annual; culms 2-9 dm. long, basally leafy and 2-8 mm. thick, apically 
0.7-4 mm. thick; inflorescences 2-13 cm. long, of 3 to 12 very unequal peduncles 
each bearing a lax spike 12-40 mm. long and 12-23 mm. thick, of 10 to 60 
spreading spikelets or the longer peduncles bearing secondary peduncles with 
such spikes; bracts 3 to 7, far-surpassing the inflorescence; spikelets 5-12 mm. 
long, 1.7-3 mm. broad, about 0.7 mm. thick, with 6 to 18 scales, straw-brown to 
dark-chocolate-brown, straight, the axis somewhat 4-angled, at maturity persistent, 
each internode on the fertile side with a niche for an edge of the achene and on 
the edges (at the sides of the achene) with minute winglike margins; scales 1.4- 
1.7 mm. long, 1.4-2 mm. broad, obovate, membranous, with 5 nerves at the keel- 
like median and marginally with a broad hyaline zone (albomargin) markedly 
contrasting with the brownish sides, deciduous, not much overlapping, clasping 
the achene; stamens 2 or 3; achenes lenticular, with an angle fitting into the niche 
of the internode, nearly as long as the scale, broadly obovate, apiculate, 1.2-1.5 
mm. long, 0.6-1 mm. broad, maturing to black. 

Infrequent or rare, on rocky slopes, washes and along streams, scattered in 
s.e. and Trans-Pecos Tex. and Ariz. (Cochise, Pima and Santa Cruz cos.), sum- 
mer; Afr., Madag., India, Burma, Austral.; in Am. from Arg. and Bol. n. to Va., 
N.C., S.C, Ala., La., Tex. and Ariz. 

6. Cyperus polystachyos Rottb. var. texensis (Torr.) Fern. Fig. 217. 

Tufted perennial (flowering the first year); culms 3-35 cm. long, basally 0.8-3 
mm. thick, apically 0.5-1.5 mm. thick, wiry; leaves basal, mostly shorter than the 
culms; inflorescence 12-60 mm. long, of several unequal peduncles (these, es- 
pecially in coastal populations, suppressed so that inflorescence is congested) with 
glomerules or short lax spikes, or rarely the longer ones with secondary peduncles 
1-3 mm. long each with a glomerule or lax spike; glomerules or lax spikes with 
5 to 10 mostly spreading spikelets; bracts 1 to 6, the longer ones usually about 
twice as long as the inflorescence; spikelets 4-25 (-43) mm. long. 0.7-2 mm. 
broad, about 0.5 mm. thick, with 10 to 40 (to 60) scales, brownish-buff to tawny- 
stramineous, straight, the axis slightly 4-angled, at maturity persistent, each inter- 
node on its fertile side with a niche for one edge of the achene, near the base of 
the niche with minute hyaline wings that narrow and join abaxially forming a 
minute cup at the base of the achene (use a strong lens!); scales 1.4-2 mm. long, 
about 1 mm. broad, ovate, appressed, much-overlapping, with 3 obscure nerves at 
the keel-like median, deciduous; stamens 2; achene lenticular, with an angle fitting 
the niche of the internode, about 1 mm. long, oblong to narrowly oblong, ripen- 
ing through brown to black. Incl. var. leptostnchyus Boeck. 

Locally abundant in seasonally moist sand, in muddy shallows, on vegetation 
mats in lakes, and at edge of stream, in Okla. (McCurtain and Johnston cos.), 
e. and s.e. Tex. and coastal part of Rio Grande Plains, spring-fall; widespread 
in Am. n. to Mass., Pa., Mo., Ark., Okla. and Tex.; the var. polystachyos (C. 
filicinus Vahl) occurs in coastal areas, Mass. to Va.; the var. paniculatus (C. 
vulgaris var. teretifructus (Steud.) Miq.) occurs widely in trop. of both hemi- 
spheres. 

7. Cyperus flavescens L. Fig. 216. 

Tufted annual; culms 10-25 cm. long, basally 0.8-1.9 mm. thick, apically 
0.7-1.1 mm. thick; inflorescence a congested (compound) sessile head of 10 to 35 

426 




Fig. 217: Cy perns polystachyos var. texensis: a, habit, about X i/^; b, spikelet, 
about X 8; c, scale, X 40; d, achene, X 40. (Courtesy of R. K. Godfrey). 




Fig. 218: Cy penis niger var. capitatus: a, scale, showing keel and obtuse apex, 
X 16; b, flower with scale removed, showing the bifid style and the 2 stamens, X 16; 
c, mature achcne, showing piincticulate surface. X 16; d. capitate inflorescence and the 
involucral leaves unequal in length, X -,\\\ e, habit, showing the short rhizome and the 
slender erect culms and leaf blades, X If,; f, spikelet, with lower scales removed to 
show the fracliflcx rachis, X 4. (From Mason, Fig. 124). 



spikelets plus occasionally 1 to 3 peduncles 1-3 cm. long each with a head of 4 to 
10 spikelets; bracts 1 to 4, the longer ones usually surpassing the inflorescence; 
spikelets 6-20 mm. long, 1.8-3 mm. broad, about 0.8 mm. thick, with 22 to 40 
scales, mostly straight, uniformly stramineous to ochre-stramineous, the axis per- 
sistent straightish, flattened, essentially wingless, each internode with a niche into 
which fits an angle of the achene; scales deciduous, 1.5-2 mm. long, 1.2-1.6 mm. 
broad, ovate, with 3 nerves in the keel-like median; stamens normally 3; achene 
lenticular (biconvex), about 0.9 mm. long and 0.6 mm. broad, obovate, sub- 
stipitate, short-apiculate. ripening to black, surficially shiny and with rectangular 
linear (vertical) cells (the rows of these cells marked off by horizontal wavy 
usually discolored sutures). Incl. var. pooefonnis (Pursh) Fern. 

Infrequent or rare in moist or wet sand, wet meadows, ditches and on seepage 
slopes, in Okla. (Waterfall), e., s.e. and n.-cen. Tex., July-Nov.; widespread (in 
several varieties) in warm regions; in Am. n. to N.Y., Pa., Mich., Mo. and Kan. 

8. Cyperus niger R. & P. Fig. 218. 

Annual or usually weak perennial occasionally forming mats by rooting or very 
shortly decumbent culms; aerial parts 1-4 (-6) dm. long, mostly erect, sub- 
basally 1-2 mm. thick, apically 0.4-1.4 mm. thick; leaves few, mostly much 
shorter than the culms; inflorescence commonly of a single sessile irregular head 
1-2 cm. thick of 3 to 30 spikelets, rarely more elaborate with a sessile head plus 
2 or 3 peduncles to 4 cm. long each with a lax irregular head or glomerule of up 
to 20 spikelets; bracts 1 to 3, the longest far-surpassing the inflorescence and 
(when young) commonly erect (like a continuation of the culm), later spreading; 
spikelets 7-12 mm. long, 1.7-2.2 mm. broad, about 0.7 mm. thick, with 10 to 22 
scales, straight, pale-chestnut-brown or often with darker blotches of chestnut on 
each scale, rarely almost totally dark-brown, the axis persistent, somewhat 4-angled 
but essentially wingless, each internode on the fertile side with a niche into which 
fits an angle of the achene; scales about 2 mm. long, much-overlapping, with 
about 3 nerves crowded in the arcuate keel-like median, otherwise smooth and 
shiny, deciduous; stamens 2; achene lenticular (biconvex) about 1 mm. long, 
elliptic, apiculate, surficially nearly featureless, ripening through shades of brown 
to nearly black, oriented so an angle fits into the internode niche. C. melano- 
stachys H.B.K. 

We have two varieties. 

Var. castaneus (Pursh) Kiikenth. With usually lax elaborate inflorescences. 
C. bipartitus Torr., C. rividaris Kunth. Rare in moist or wet sandy loam in e. Tex. 
(Austin and Washington cos.); from Que. w. to Minn, and Neb., s. to Ga., Ala., 
Miss, and Tex.; also Calif, and Ore. 

Var. capitatus (Britt.) O'Neill. Fig. 218. With relatively light-colored (chestnut- 
brown) glumes and strongly apiculate achenes. Local in creeks in igneous Trans- 
Pecos Tex. mts. at elev. of more than 4,000 ft., and Ariz. (Apache, Navajo, 
Yavapai, Greenlee, Gila, Cochise, Santa Cruz and Pima cos.), summer-fall; from 
Cuba and C.A. n.w. to Calif., Ariz, and Colorado. 

9. Cyperus odoratus L. Fig. 219. 

Tufted perennial, rarely rhizomatous or often flowering the first year and 
behaving annual; culms often slightly tuberous-thickened basally, to 9 dm. long, 
subbasally 1-6 mm. thick, just beneath the inflorescence 0.3-3 mm. thick; inflores- 
cence 1-45 cm. long, of numerous very unequal spreading or ascending primary 
peduncles the longer of which usually bear several unequal secondary peduncles, 
all eventually bearing lax to subdense spikes of rather numerous spreading spike- 
lets; bracts 3 to 10, the longer far-surpassing the inflorescence; spikelets quite 
variable in size (about 1 mm. broad and thick) and number of scales (4 to 30), 
each internode of the axis unilaterally (on the sterile side) postanthetically bulbous 

429 




iT'^" v^.'< ^yP'''"' ''<l<]>-a'us- a. habit, X i/.; b, spikelet, X 5; c, scale, X 15; d, 
bene, X 15. (Courtesy of R. K. Godfrey). , , , 



achene, 




Fig. 220: Cyperus articulatus: a, habit, X i/4; b, spikelet, X 4; c, scale, X 20; d, 
achene, X 25. (Courtesy of R. K. Godfrey). 



with white cartilaginous thickening and on the fertile side with 2 hyaline wings 
(eventually becoming papery) clasping the achene and at the base of each inter- 
node (above each node) abscising so that the whole spikelet breaks up into joints 
each comprising a scale, the next lower internode and the attached wings and 
achene; scales small, brownish, with a number of nerves, each persistent on its 
joint; stamens 3; achenes brownish, unequally trigonous, the 2 smaller (sharper) 
angles adaxial, clasped by the wings. C ferax Rich., C. speciosus Vahl, C. fer- 
ruginescens Buckl. 

In mud of swamps, ditches and streams, at edge of lakes and creeks, abundant 
in all parts of Tex. and Okla., N.M. (San Juan Co.) and Ariz, (widespread); 
perhaps our most abundant flatsedge and one of the most variable, but it is im- 
possible to distinguish segregate taxa, spring-fall, occasionally, winter; semi- 
cosmopolitan in temp, and trop. regions. Passing through the form called C. 
Eggersii Boeck. to C. macrocephalus Liebm. with a headlike inflorescence. 

10. Cyperus articulatus L. Chintul. Fig. 220. 

Perennial forming colonies with creeping scaly rhizomes 1.5-6 mm. thick; culms 
rising at intervals 7-50 mm. apart on the rhizomes, erect, 5-14 dm. long, 2-8 
mm. thick, nearly terete or only vaguely triangular, septate at intervals of 5-50 
mm.; leaves only few, toward the base, reduced to small essentially bladeless 
sheaths; bracts few, 3-11 mm. long; inflorescence comprising 4 to 12 glomerules 
of spikelets, some glomerules nearly sessile and some on slender nodding peduncles 
to 12 cm. long; glomerules with up to 20 spikelets, essentially bractless; spike- 
lets 6-25 mm. long, about 2 mm. broad, laterally compressed, the axis remaining 
intact after the scales and achenes fall; scales keeled, the lower sides decurrent on 
the spikelet axis as readily deciduous wings 0.2-0.4 mm. wide and about 1 mm. 
long; stamens 3; connective very minutely prolonged beyond the end of the 
anther; achene unequally trigonous. 

Abundant in moist or wet clay meadows, in mud on edge of lakes, along streams 
and above inlets, s.e. Tex. and Rio Grande Plains, rare n. to s. part of n.-cen. Tex. 
(Comal, Travis and McLennan cos.), May-Oct.; Braz. and Col. n. to Gulf States. 

11. Cyperus Iria L. Fig. 221. 

Tufted annual; culms 8-60 om. long, erect; leaves crowded near the base, 
shorter than the culm; inflorescence 4-12 cm. long (not including the bracts), an 
umbel-like aggregation of 5 to 8 extremely unequal peduncles each bearing an 
irregular panicle of several spikes each with a number of ascending spikelets the 
total inflorescence with 100 to 600 spikelets; bracts about 4, much longer than 
the inflorescence; spikelets 3-10 mm. long, 1.3-1.8 mm. broad, with 2 to 22 
flowers, the axis persisting and remaining intact even after the achenes and scales 
fall; scales nearly orbicular or as seen laterally and folded appearing obovate, 
about 1.5 mm. long, rounded to emarginate, mucronulate, with about 4 nerves in 
the incurved weakly keel-like median, brownish or golden-brown, the hyaline 
margins tending to fold in and meet on the adaxial side of the achene, decurrent 
below as thin striations but not as wings; stamens 2 or 3; achene trigonous, 1.2- 
1.3 mm. long. 

Wet clay in coastal rice-growing areas, in water of freshwater canals and on 
edge of ponds, in Okla. (McCurtain. LeFlore and Pittsburgh cos.) and s.e. Tex. 
(Colorado, Harris, Jackson and Matagorda cos.), locally common, July-Sept.; s.e. 
Asia (n. to Korea and Mongolia), N. Austral., Malaysia, India, Afr. Madag., 
Iran, Afghan., adv. in scattered parts of Am., especially in the Gulf and s. Atl. 
States; W.I. 

432 




Fig. 221: Cyperus Iria: a, habit, X V2; b, spikelet, X 10; c, scale, X 17; d, achene, 
X 19. (Courtesy of R. K. Godfrey). 




Fig. 222: Cy perns difformis: a, flower without scale, X 40; b, group of spikelets, 
X 8; c, ray of inflorescence, showing globose head of spikeiels and part of scabrellate 
margin of involucral leaf, X 2; d, trigonous achene, showing the minutely cellular sur- 
face, X 2H; e, culm (cross section), X 6; f, scale, X 40; g, habit, showing the umbellate 
inflorescences with involucral leaves of unequal length, X Va- (From Mason, Fig. 130). 



12. Cyperus diflFormis L. Fig. 222. 

Annual sedge with fibrous roots and cespitose culms; culms smooth, 15-50 cm. 
tall; leaves 2 to 4 on a culm, about as long as the culm, 1-4 mm. wide, scaberulous 
on margins near apex; involucral leaves 2 or 3, unequal in length; inflorescence 
umbellate, the globose heads of spikelets sessile or on rays to 7 cm. long; spikelets 
linear, obtuse, subcompressed, 4-8 mm. long; rachis straight, unwinged; scales 
roundish, obtuse, 0.6-0.8 mm. long, membranous, green with brown sides, 
readily deciduous; stamens 1 or 2; achene trigonous, obovate, minutely mucronu- 
late, 0.5 mm. long, pale-greenish-brown, the surface minutely cellular. 

Common weed in rice fields, Okla. (LeFlore Co.) and Ariz. (Mohave Co.); 
Okla., N.M., Ariz., Calif, and Mex., nat. of Asia. 

13. Cyperus aristatus Rottb. Fig. 223. 

Tufted annual with persistent coffee-and-chicory or curry powder odor (like 
Ulmus rubra, Phyllanthus ericoides, Gnaphalium obtusifolium, flowers of Bomba- 
caceae, etc.); culms 1-20 cm. long, the longer leaves often equaling or surpassing 
them; inflorescence of 1 to 3 heads, essentially sessile at the summit, often with 
1 to 6 additional shortly peduncled ones; bracts 2 to 4, the longer ones far- 
surpassing the inflorescence, often ascending; heads 5-20 mm. thick, often slightly 
prolate, with 2 to 50 spikelets; spikelets 4-14 mm. long, 2-3 mm. broad, about 
0.5 mm. thick, laterally compressed, straight, with 5 to 30 scales, brown to yellow- 
brown to tawny-brown, the axis essentially wingless, at maturity eventually decidu- 
ous as a unit from the head axis; scales deciduous either before or after fall of 
the spikelet axis, 2-2.5 mm. long, about in the distal third the length being a 
very slender sharp acuminate-subulate prominently recurved tip, with 7 or 9 
evenly distributed nerves; stamen 1; achene 0.7-1 mm. long, 0.2-0.5 mm. broad, 
from nearly linear-oblong to obovoid, dark-brown. C. inflexus Muhl. 

In wet soils, on edge of lakes and ponds and marshes, in Okla. (Stephens, 
Mcintosh, Alfalfa, LeFlore and Johnston cos.) to Ariz. (Navajo and Coconino, s. 
to Cochise, Santa Cruz and Pima cos.) throughout Tex. (except Plains Country), 
scattered, spring-early winter; nearly cosmopolitan in temp, and trop. areas. 

In extreme south coastal Texas occurs the var. Runyonii O'NeiU with the 
achenes at the extremes of greatest length and narrowness allowed here. 

14. Cyperus amabilis Vahl var. macrostachyus (Boeck.) Kiikenth. 

Rachilla articulated with the rachis at the base, wingless; bracts 3 to 6, scarcely 
if at all exceeding the inflorescence; rays to 10; spikelets 10-18 mm. long, 
1.5-2.5 mm. wide, lustrous, reddish-brown, digitate-radiate in heads; scales 3- 
nerved, aristate, 1.5-2.7 mm. long; achene trigonous; style branches 3; stamen 
1 (rarely 2). 

Ariz. (Santa Cruz Co.) ; to S.A. 

15. Cyperus seslerioides H.B.K. 

Tufted perennial forming tough fibrous black mats (bulblike bases connected 
by extremely short branching rhizomes); culms 10-25 cm. long, erect, basally 
about 1 mm. thick, apically about 0.5 mm. thick; leaves 2 or 3 per culm, basal, 
1-2 mm. broad; inflorescence (excluding bracts) 6-12 mm. long, contracted into 
a single densely flowered several-lobed subhemispheric whitish or pallid-brownish 
( Dichromena-Uke) head; bracts 3 or 4, linear, 2 to 10 times as long as the head, 
spreading or reflexed; spikelets 3-7 mm. long, 2-2.5 mm. broad, compressed, 
with 10 to 20 flowers, the axis wingless and persistent as a unit after the scales 
have fallen; scales 1.5-2.7 mm. long, 1.1-1.6 mm. broad, membranous, 3-nerved, 
acuminate, sharp; stamen 1; achene 0.7-1 mm. long and nearly as thick, sub- 
orbicular, strongly 3-angled with concave sides, maturing to a very dark-brown. 

435 




Fig. 223: Cypcrus arislatus: a and b, habit, showing the umbellate inflorescences, 
each ray bearing a capitate cluster of spikelets, X %; c, compressed spikelet, showing 
the recurved awns of scales, X 8; d, scale, showing the strong nerves, X 32; e. mature 
achene with puncticulate surface, X 24; f, ray of inflorescence, showing capitate ar- 
rangement of spikelets, X I'j; g, rachis, showing persistent stamens, arrangement of 
achenes and the trifid styles, X 20. (From Mason, Fig. 128). 




Fig. 224: Cy perns acuminatus: a, spikelet, showing the recurved tips of scales, X 8; 
b, scale, 3-nerved, the surface cellular-reticulate, X 20; c, trigonous achene, X 20; d, 
habit, showing the globose heads of spikelets on rays of unequal length, X %; e, flower 
without scale, X 20; f, ray of inflorescence, showing globose head of spikelets, X P/^. 
(From Mason, Fig. 129). 



Scarce in shaded moist ravines high in the Chisos Mts. in the Tex. Trans-Pecos 
and Ariz. (Cochise and Santa Cruz cos.), summer; Venez., Guat., Mex., Ariz, 
and Tex. 

16. Cypenis acuminatus T. & H. Fig. 224. 

Short-lived perennial, flowering the first year, tufted; culms 1-4 dm. long, 
erect, basally with a few leaves and 0.7-1.2 mm. thick, just beneath the inflores- 
cence 0.4-0.8 mm. thick, roundly triquetrous, smooth or with more or less 
abundant microscopic knobs more or less at right angles to the culm; leaves few, 
0.5-2 mm. broad, the longer ones sometimes equaling the culms, basally not sep- 
tate; inflorescence (excluding bracts) 2-8 cm. long, of 2 to 5 very unequal pri- 
mary peduncles, the shorter of which bear nearly hemispherical to spherical 
glomerules of 13 to 25 spikelets, the longer ones with such glomerules (rarely 
compound or with secondary peduncles) of up to 55 spikelets; bracts 3 or 4, the 
longer ones nearly erect and far-surpassing the inflorescence; spikelets 4-10 mm. 
long, 1.5-2.5 mm. broad, nearly linear, with 12 to 44 flowers, stramineous to 
brownish-stramineous or rarely tawny-stramineous, laterally compressed, the 
axis slightly flattened, wingless and persistent as a unit after the scales and achenes 
have fallen; scales laterally membranous, inconspicuously cellular, medially firm- 
membranous. 1.3-1.9 mm. long, in the proximal fifth to fourth the length with a 
flattish area about 0.2 mm. broad dorsally (abaxially), the 2 lateral parts 0.4-0.6 
mm. broad (the scale spread out 0.8-1.2 mm. broad, ovate or narrowly so), 
tapering distally to the acute apex, with 3 nerves (the inconspicuous midnerve 
plus on each side a conspicuous nerve about three eighths to two fifths the dis- 
tance from the midnerve to the margin), the dorsal (median) portion of the 
scale (as the scale is folded in position in the spikelet) incurved in the lower part, 
in the distal part either straight or usually with a slight to marked excurvature so 
that the whole is weakly S-shaped; stamen 1; achene elliptic, 0.9-1.1 mm. long, 
0.35-0.45 mm. thick, sharply trigonous, basally short-stipitate. apically prolonged- 
acuminate, pale-brown, occasionally maturing to brown. C. cyrtolepis T. & H. 

Abundant in moist places, wet soil and sandy shore of lakes and ponds, and 
in shallow water, in Okla. (Stephens, Love, Ottawa, Comanche, McCurtain and 
Mayes cos.), e., s.e., n.-cen. Tex. and Rio Grande Plains, rare in Edwards Plateau 
(Central Mineral Region only) and the Trans-Pecos (Jeff' Davis and Presidio cos.) 
and Ariz. (Graham, Gila, Cochise and Pima cos.), almost all year; Mo. and 
N.C., s. to La., Tex. and Coah.; also Ga., Ariz., Nev., Calif, and Ore. 

Young specimens strongly simulate dwarf specimens of C. reftexiis. 

17. Cypenis surinamensis Rottb. Fig. 225. 

Short-lived tufted perennial, flowering the first year; culms 1-4 (-8) dm. long, 
with scattered microscopic rctrorse projections like shark's teeth, erect, basally 
with a few leaves and 0.8-3.5 (-4.5) mm. thick, just beneath the inflorescence 
0.4-1.5 mm. thick and bluntly triquetrous; leaves few, the longer ones nearly as 
long as the culm, basally usually with scattered microscopic transverse septa be- 
tween the nerves; inflorescence (excluding bracts) 1-8 cm. long, of (4 to) 7 to 12 
very unequal primary peduncles the shorter of which bear nearly spherical 
glomerules of 8 to 25 spikelets, the longer usually with several very unequal 
secondary peduncles each with a nearly spherical head of 11 to 35 spikelets; 
bracts 5 to 7, the longer ones far-surpassing the inflorescence; spikelets 3-6 (-14) 
mm. long, 1.8-2.5 mm. broad, nearly linear, with 10 to 20 (to 30) flowers, 
stramineous to chartreuse or ochraceous, laterally compressed, the axis slightly 
flattened, wingless and persistent as a unit after the scales and achenes have fallen; 
scales laterally membranous, inconspicuously cellular, medially slightly firmer, 
1-1.5 mm. long, in the proximal third to three fifths the length with a flat abaxial 
(dorsal) area 0.15-0.2 mm. broad, the 2 lateral parts 0.4-0.6 mm. broad (the 

438 




Fig. 225: Cyperus surinamensis: a, habit, X V2; h, spikelet, X 10; c, scale and 
achene, X 40. (Courtesy of R. K. Godfrey). 




Fig. 226: Cy perns virens: a, habit, X Vy, b, spikelet, X 8; c, scale, X 26; d, achene, 
X 26. (Courtesy of R. K. Godfrey). 



scale when spread out 0.9-1.2 mm. broad, ovate), rounded or slightly acute, with 
3 nerves (the inconspicuous midnerve plus the 2 prominent laterals which form 
the proximal keels); dorsum of the scale as it is folded in position in the spikelet 
gently incurved in the proximal part, nearly straight distally; stamen 1; achene 
elliptic-oblong or oblong, 0.7-0.8 mm. long, 0.25-0.3 mm. thick, bluntly trigo- 
nous, dark-rosy-brown, basally minutely stipltate, apiculate or shortly acuminate. 
Infrequent in moist places, wet meadows and pastures, s.e. Tex. and coastal 
parts of Rio Grande Plains, rare in n.-cen. and e. Tex., July-Nov., rarely spring; 
Arg. and Bol. n. to Fla., La. and Tex. 

18. Cypenis virens Michx. Fig. 226. 

Tufted perennial; culms 5-1 1 dm. long, erect, basally leafy and 5-12 mm. thick, 
just beneath the inflorescence 3-8 mm. thick, sharply triquetrous and often with 
microscopic rigid antrorse projections like shark's teeth especially on the angles; 
leaves several, the longer ones almost as long as the culm, basally usually with 
numerous short incomplete transverse septa visible after pressing and drying; in- 
florescence (excluding bracts) 3-13 cm. long, of 6 to 14 very unequal primary 
peduncles, the shorter of which bear nearly spherical heads of 12 to 30 spikelets, 
the longer ones bearing some shorter unequal secondary peduncles each with a 
head of 16 to 40 spikelets; bracts 5 to 9, the longer ones far-surpassing the 
inflorescence; spikelets 6-13 mm. long, 2.5-3.3 broad, linear, acute, with 10 to 
36 flowers, stramineous (young) to olive-brown or grayish-brown (mature), 
laterally compressed, the axis flat, wingless and persistent as a unit after the scales 
and achenes have fallen; scales laterally firm-membranous and with visible cells, 
medially chartaceous (to eventually subcartilaginous), 2-2.4 mm. long, in the 
proximal third to five eighths the length definitely bicarinate with a flat area or 
shallow groove 0.25-0.4 mm. broad dorsally (abaxially), the 2 lateral parts 
0.5-0.6 mm. broad (therefore the scale spread out 1.2-1.5 mm. broad just below 
the middle), in the lower half linear, gently tapering distally, with 5 nerves (1 of 
these being the inconspicuous midvein between the keels), including 1 nerve at 
each keel and 1 on each lateral face about a fourth to a third the distance from 
the keel to the margin, the whole scale (as folded in the spikelet) incurved slightly 
in the distal half; stamen 1 ; achene linear, triquetrous, basally stipitate. apically 
acuminate, 1-1.5 mm. long, 0.3-0.5 mm. thick, brownish with a very thin trans- 
lucent surficial layer of cells. 

Abundant in moist places, in shallow water and on edge of streams, ponds and 
lakes, in Okla. (McCurtain, Sequoyah, Muskogee, LeFlore and Osage cos.) and 
s.e. Tex., frequent in e. Tex. and coastal parts of Rio Grande Plains, May-Oct.; 
Urug. and Ecu. n. to N.C. and the Gulf States, adv. in Calif. 

Through error, the name C virens has been widely misapplied to C. pseudo- 
vegetus. The 2 taxa are extremely closely related and occasionally hybridize. 
Young specimens of C. virens greatly resemble C. pseudovegetus. 

19. Cyperus ochraceus Vahl. Fig. 227. 

Perennial, tufted; culms 11-80 cm. long, basally 2-5 mm. thick, apically 
bluntly trigonous, 1-2.7 mm. thick, erect, smooth; leaves several, basally aggre- 
gated, the longer ones about as long as the culm, not septate-nodulose; inflores- 
cence (excluding bracts) 25-185 mm. long, of 6 to 12 very unequal primary 
peduncles, the shorter of which bear nearly spherical lax heads of 4 to 15 spike- 
lets, the longer ones bearing some short unequal secondary peduncles each with 
a head of 4 to 24 spikelets; bracts 5 to 8. the longer ones far-surpassing the 
inflorescence; spikelets 5-20 mm. long, 2-2.5 (-3) mm. broad, linear, acute, with 
10 to 30 (to 40) flowers, olive-stramineous (young) to olive-yellow or yellowish- 
brown (mature), laterally compressed, the axis flat, wingless and persistent as a 

441 




Fig. 227: Cyperus ochraceus: a. habit, X %; b, spikelet, X 3; c, scale, X 25; d, 
achene, X 20. (Courtesy of R. K. Godfrey). 



unit after the scales and achenes have fallen; scales laterally membranous and with 
visible cells, medially chartaceous (eventually subcartilaginous), 1.5-2 mm. long, 
in the proximal half to two thirds definitely bicarinate with a flat area or shallow 
groove (0.3-0.5 mm. broad) dorsally (abaxially), the 2 lateral parts 0.6-0.7 mm. 
broad (therefore the scale when spread out 1.5-1.9 mm. broad at the very base, 
tapering all the way to the blunt apex), with 5 nerves (the midvein in the 
channel between the keels inconspicuous) including a nerve at each keel and 
one on each lateral face about a third the distance from the keel to the margin, 
the whole scale as folded in position in the spikelet incurved slightly in the distal 
half; stamen solitary; achene ovoid, 1.3-1.5 mm. long, 0.5-0.6 mm. thick, nearly 
terete or obscurely triangular, slightly stipitate, apically acuminate and passing 
imperceptibly into the style, black when mature but appearing dark-iridescent- 
gray because of outer 1-cell thick covering of translucent cells; stigmas 3. 

Abundant in shallow water and mud, and edge of lakes and ponds, Rio 
Grande Plains (n. to Bexar Co.) and s.e. Tex., throughout year, most profuse 
Sept.-Nov.: C.A., W.I., Mex.. n. to Cuba and La. 

20. Cyperus pseudovegetus Steud. 

Tufted perennial, often slightly more loosely tufted than in C. virens by elonga- 
tion of rhizomes 2-5 mm. between culms; culms 3-8 dm. long, erect basally 
with a few leaves and 2-5 mm. thick, just beneath the inflorescence 1-2.2 mm. 
thick, roundly triquetrous, smooth or rarely with microscopic antrorse scabrous- 
ness; leaves few to several, the larger ones almost as long as the culms, basally 
often with minute transverse septa between the close veins; inflorescence (ex- 
cluding bracts) 2-9 cm. long, of 3 to 10 very unequal primary peduncles, the 
shorter of which bear dense strongly 3- to 8-lobed glomerules or heads of 15 to 
50 spikelets, the longer ones bearing some shorter unequal secondary peduncles 
each with such a head; bracts 3 to 6, the longer ones far-surpassing the inflores- 
cence; spikelets 2.5-4 mm. long, 2.3-3 mm. broad, narrowly ovate, blunt or 
slightly acute, with 6 to 14 flowers, tawny stramineous to (very slightly reddish-) 
brown, laterally compressed, the axis flat, wingless and persistent as a unit after 
the scales and achenes have fallen; scales laterally membranous with visible cells, 
medially firm to chartaceous, 1.8-2.5 mm. long, in the proximal fourth to third 
the length bicarinate with a flat or shallowly groovelike area 0.1-0.2 (-0.3) mm. 
broad dorsally (abaxially), the 2 lateral parts 0.2-0.4 mm. broad (therefore the 
scale spread out is 0.6—0.7 mm. broad near the middle, almost linear), tapering 
only at the very tip, with 5 inconspicuous nerves in the median portion, the whole 
scale (as folded in the spikelet) incurved-falcate; stamen 1; achene linear, 1-1.3 
mm. long, 0.2-0.3 mm. thick, bluntly trigonous, basally short-stipitate apically 
acuminate, often slightly falcate, brown with a very thin translucent-iridescent 
surficial layer of cells. C. arenicola Steud. 

Locally frequent in moist places, about lakes and ponds, in marshy areas and 
seepage areas, in Okla. (Pushmataha, McCurtain, Pittsburgh, Atoka, Love and 
LeFlore cos.), e. and s.e. Tex., infrequent in n.-cen. Tex., May-Sept.; Gulf States 
and n. to N.J., Ind.. III., Mo. and Kan. 

Through error this species, in some works, has been called C. virens. 

21. Cyperus reflexus Vahl. 

Perennial with scaly creeping rhizomes 1-1.5 mm. thick; culms contiguous or 
several mm. apart along the rhizome, 3-7 dm. long, erect, basally with a slightly 
bulblike enlargement, with a few leaves and 1-2.5 mm. thick (just above the 
"bulb"), just beneath the inflorescence 0.5-1.3 mm. thick, roundly triquetrous, 
smooth; leaves few, the longer ones about as long as the culms or shorter, basally 
not septate; inflorescence (excluding bracts) 15-50 mm. long, of 3 to 8 very 

443 




Fig. 228: Cy perns Haspon: a, habit, X %; b, spikelet, X 4; c, scale, X 25; d, 
achene, X 70. (Courtesy of R. K. Godfrey). 



unequal primary peduncles the shorter of which bear very dense strongly 3- to 
8-lobed glomerules of 25 to 50 spikelets, the longer ones (more than 15 mm. long) 
with dense strongly 15- to 30-lobed compound glomerules of up to 100 spikelets; 
bracts 3 to 5, the longer ones far-surpassing the inflorescence; spikelets 3-5 mm. 
long, 1.5-2.2 mm. broad, nearly linear in the lower part, distally tapered and 
apically crowded, with 8 to 12 flowers, red and green, laterally compressed, the 
axis flat, wingless and persistent as a unit after the scales and achenes have 
fallen; scales laterally red, membranous, inconspicuously cellular, medially firm- 
membranous, 1.5-2 mm. long, in the proximal fourth the length with a narrow 
flat area about 0.2 mm. broad dorsally (abaxially), the 2 lateral parts red, 0.5- 
0.6 mm. broad (therefore the scale spread out is about 1.1 mm. broad, narrowly 
ovate), tapering distally to the slightly acute tip, with 5 inconspicuous nerves in 
the median portion, the median portion of the scale (as folded in position in the 
spikelet) with a distinct curve in the proximal part but distally nearly straight; 
stamen 1; achene oblong or elliptic-oblong, 0.9-1 (-1.2) mm. long, 0.3-0.4 mm. 
thick, sharply trigonous, basally short-stipitate, apically shortly acuminate or pyra- 
midal, pale-brown (finally dark-fuscous beneath the outer cellular layer). C 
rufescens Torr. 

Rare in e. and s e. Tex., inland to Houston, Bastrop and DeWitt cos., in moist 
or wet sand, spring-summer; otherwise scattered in S.A.,'Mex., La. and Okla. 
Only mature material can be determined with confidence. 

22. Cyperus phaeolepis Cherm. 

Densely tufted perennial; culm 3-5 (-9) dm. long, erect, basally 2-3 mm. 
thick, just beneath the inflorescence 1.7-2 mm. thick, irregularly striate; leaves 
few, basal, reduced to usually reddish-brown sheaths with diagonal orifices, the 
"blades" only a few mm. long; inflorescences (excluding bracts) 1-2 cm. long, 
of 8 to 12 unequal peduncles each bearing a headlike (occasionally compound) 
glomerule of 8 to 15 spikelets; bracts 9 to 13, spreading, 3-10 cm. long, (1-) 
3-5 mm. broad, abruptly acute; spikelets 3-6 mm. long, 1.5-2 mm. broad, with 
12 to 18 flowers, compressed slightly, the axis flat, wingless and remaining intact 
as a unit after the scales have fallen (achenes sometimes more persistent); scales 
1.3-1.5 mm. long, about as broad, broadly ovate when unfolded, obtuse, laterally 
membranous, whitish or with a chestnut-tawny splotch, dorsally-proximally flat, 
the midnerve obscure and the 2 other nerves forming keels on each side of the 
flat area for about three eighths the total length; stamens 3; achenes 0.7-0.8 mm. 
long, ellipsoid, obscurely trigonous, pallid-brown turning brown. C. albiflorus 
Cherm. 

Rare in moist or wet places, s.e. (Galveston Co.) and Trans-Pecos (Pecos Co.) 
Tex., escaped, Apr.-June; Madag.; Tex. 

23. Cyperus Haspan L. Fig. 228. 

Short-lived tufted perennial, flowering the first year; culms 1-7 dm. long, 
erect, basally 2-5 mm. thick, just beneath the inflorescence 1.5-3 mm. thick, 
sharply trigonous but soft and easily pressed flat; leaves basal, the lowest ones 
bladeless, some of the upper ones consisting of sheaths with oblique orifices or 
even with soft blades 1-10 cm. long; inflorescence (excluding bracts) 4-12 cm. 
long, of 10 to 15 extremely unequal primary peduncles the shorter of which each 
bears a lax glomerule of 3 to 12 spikelets and the longer with several secondary 
peduncles each with a lax glomerule (or occasionally bearing unequal tertiary 
peduncles with glomerules); bracts usually 2, one of them 0.3 to 1 (to 2) times 
as long as the inflorescence, the other much shorter and inconspicuous; spikelets 
4-10 mm. long, about 1 mm. broad, linear, compressed, brown, with 8 to 30 
flowers, the axis persistent as a unit after the scales have fallen (the achenes and 

445 




Fig. 229: Cy perns erythrorhizos: a, scale with rachis wings attached, X 20; h, part 
of spikelet, with some scales removed to show inner hyaline membranes forming wings 
on rachis, X 20; c, Hnear spikelet, X 8; d, mature achene, trigonous and with surface 
finely cellular, X 28; e, habit, showing the compound umbels and their numerous in- 
volucral leaves which are unequal in length, X 's; f, flower, X 20; g, ray of inflores- 
cence, showing branches of divaricate spikelets and scabrellate involucral leaves, X %. 
(From Mason, Fig. 133). 



filaments often less readily caducous than the scales); scales 1.2-1.6 mm. long, 
0.8-1 mm. broad, obtuse, fragile-membranous, 3-nerved (actually with 5 nerves 
but the ones nearest the margin extremely inconspicuous and in some specimens 
weakly developed); stamens 3; achene globose-obovate to subglobose, obscurely 
trigonous, 0.4-0.7 mm. long, 0.4-0.5 mm. thick, whitish, roughened. Incl. var. 
americanus Boeck., C. juncoides Lam. 

Infrequent in moist places, in water of swift stream, in wet meadows, on 
seepage slopes, in e. and s.e. Tex. and coastal parts of Rio Grande Plains, inland 
to Guadalupe Co., June-Oct.; widely distributed in warm regions. 

24. Cypenis giganteus Vahl. 

Perennial, densely tufted, culms 4-15 dm. long; leaves reduced to mere long 
brown sheaths at the base of the culm; inflorescence an umbel-like aggregation of 
10 to 25 primary peduncles (the longest only about twice as long as the shortest), 
each bearing an umbellule of 4 to 8 peduncled lax spikes with elongate axes and 
10 to 20 (reportedly up to 50) spreading spikelets; spikelets about 1 mm. broad 
or narrower, laterally much-compressed, 4-10 mm. long, with 8 to 18 flowers; 
bracts of umbel about as many as the primary peduncles and surpassing the umbel; 
bracts of umbellules as many as the spikes and mostly exceeding them; spikelet 
axis persistent as a unit after the achenes and scales fall; lower margins of scales 
decurrent on the spikelet axis as hyaline readily deciduous wings 0.2-0.3 mm. 
broad and more than 1 mm. long; stamens 3; anthers with 2 cells, the connective 
between the cells prolonged 0.2-0.5 mm. beyond the end of the anthers; achene 
unequally trigonous, the 2 adaxial angles much smaller (sharper) than the abaxial 
one. 

Rare in extreme s.e. Tex. (Orange Co.) in marshes, probably not a persistent 
member of our flora; Parag., Urug. and Col. n. to Hond. and Gr. Ant. 

25. Cypenis alternifolius L. Umbrella flatsedge, umbrella plant. 

Tufted perennial; culm 3-15 dm. long, erect, basally 5-20 mm. thick, just below 
the apex 1-5 mm. thick, triangular; leaves few, basal, reduced to sheaths, apically 
with a diagonal orifice and a short flat triangular blade 5-50 (-100) mm. long; 
inflorescence (excluding bracts) 3-10 cm. long, of 15 to 25 slightly unequal 
primary peduncles each bearing a short headlike raceme of 8 to 15 short- 
peduncled spikelets; bracts 15 to 25, 15-40 cm. long, 1-15 mm. broad, spreading 
(forming an umbrella); spikelets 5-10 mm. long, 1.5-2 mm. broad, with 12 to 30 
flowers, compressed, the axis wingless and remaining intact as a unit after the 
scales have fallen (achenes often more persistent); scales 1.6-2 mm. long, 1.4-1.6 
mm. broad when unfolded, several-nerved; stamens 3; achene trigonous, 0.6-0.9 
mm. long, 0.5-0.6 mm. thick, brown, elliptic-oblong. 

S.e. Tex., cult, in moist or wet ground and rarely escaping, summer-fall; nat. 
of the Old World, probably Afr. or Madag., widely cult, and escaping in warm 
regions. 

26. Cypenis erythrorhizos Muhl. Fig. 229. 

Tufted annual or becoming a definite perennial in s. Tex.; culms 5-14 dm. long; 
inflorescence an umbel-like aggregation of 4 to 10 long markedly unequal pedun- 
cles each bearing an irregular cluster of several nearly sessile spikes with elongate 
axes (with internodes 0-0.5 mm. long) and 15 to 70 spreading spikelets; spikelets 
about 1 mm. broad or narrower, laterally much-compressed, very thin, 3-10 
(-15) mm. long with 6 to 34 or more flowers; bracts of umbel about as many 
as primary peduncles and some about as long as the inflorescence; bracts of 
the spike clusters considerably reduced, inconspicuous; spikelet axes persistent as 
a unit after the achenes and scales have fallen; scales keeled, the lower margins 
decurrent on the spikelet axis as readily deciduous hyaline wings about 0.8 mm. 

447 




Fig. 230: Cyperus comprcssiis: a, habit, X Vy, b, spiicelet, X 5; c, scale, X 25; d, 
achen^, X 25. (Courtesy of R. K. Godfrey). 



long and 0.2-0.3 mm. broad; stamens 3; connective of anthers not surpassing the 
anther cells themselves or else projected as a red point only 0.05-0.1 mm. long; 
achene unequally trigonous. 

Abundant in marshy places, sand flats and in shallow water of lakes and ponds, 
along creeks, in Okla. (widespread), s.e. Tex., infrequent in Rio Grande Plains, 
n.-cen. and e. Tex., probably elsewhere, N. M. (Dona Ana Co.) and Ariz. 
(Coconino, Mohave and Yuma cos.), July-Dec; Ont. and e. U.S. w. to N.D., 
S.D., Neb., Kan., Okla. and N.M.; also Wash., Ore., Calif., Ariz, and Ut.; pre- 
sumably also Tam. 

Probably not sufficiently distinct from C. digitatus. 

27. Cyperus digitatus Roxb. 

Tufted perennial; culms 5-15 dm. long; inflorescence an umbel-like aggregation 
of 5 to 13 long markedly unequal peduncles each bearing an irregular cluster of 
several nearly sessile spikes with elongate axes (internodes of spike axis 0.6-2 
mm. long) and 15 to 35 spreading spikelets; spikelets about 1 mm. broad, laterally 
compressed, 7-15 mm. long, with 8 to 35 flowers; bracts of umbel about as many 
as peduncles and some as long as or longer than the inflorescence; bracts of spike 
clusters considerably reduced, inconspicuous; spikelet axes persistent as units 
after the achenes and scales have fallen; scales keeled, the lower sides decurrent 
down the spikelet axis as readily deciduous hyaline wings 0.2-0.3 mm. broad and 
about 0.8 mm. long; stamens 3; connective of anther not surpassing the anther 
cells themselves or else merely a red point 0.05-0.1 mm. long; achene unequally 
trigonous. 

Local in marshy places near Brownsville, Laredo and Corpus Christi in Rio 
Grande Plains, July-Dec; Braz., Col., Mex., W.L and Tex. 

28. Cyperus onerosus M. C. Johnst. 

Perennial with scaly rhizomes 5-80 mm. long and 1-2 mm. thick; culms 
20-49 cm. long, erect, basally leafy and 2-4 mm. thick, just beneath the in- 
florescence smooth, sharply triquetrous and 1.5-2 mm. thick; leaves few, basally 
with no transverse septation, some of the longer ones usually surpassing the 
inflorescence; inflorescence (excluding bracts) 2-12 cm. long, with 7 to 15 very 
unequal primary peduncles, the shorter of these bearing nearly spherical heads of 
8 to 25 spikelets, the longer ones bearing 3 to 12 unequal secondary peduncles 
each bearing a head of 20 to 35 spikelets; bracts about 4, the longer one nearly 
erect, exceeding the inflorescence; spikelets 7-13 mm. long, 2.5-3.5 mm. broad, 
linear, with (10 to) 16 to 26 (to 42) flowers, brownish to tawny-brown, laterally 
compressed; the axis wingless, thick, dorsiventrally slightly flattened, persistent as 
a unit after the scales and achenes have fallen, the internodes sculptured (with a 
niche for each achene); scales 2.3-2.9 mm. long, 1.2-1.4 mm. broad, ovate- 
elliptic when unfolded, basally slightly gibbous, laterally firm-membranous, 
medially chartaceous and with a midnerve and on each side 2 (rarely 3) nerves 
(the total number obscure except when the scale is young and translucent), the 
medial nerved keel-like zone (as seen in place in the spikelet) except for the 
curve at the gibbous base mostly straight or very slightly excurved to the very 
acute apex; stamens 3; achene elliptic to narrowly so, trigonous, acuminate at 
both ends, 0.7-0.8 mm. long, 0.25-0.3 mm. thick, whitish or eventually turning 
brownish. 

Locally frequent in moist or wet loose sand and pools between sand dunes, s.w. 
part of Plains Country of Tex. (Ward and Winkler cos.), June-Nov.; endemic. 

29. Cyperus compressus L. Fig. 230. 

Tufted annual (or occasionally appearing as a short-lived perennial); leaves 
few, clustered near the base, little shorter than the culms; inflorescence (not 

449 




Fig. 231: Cyperus filiculmis: a, habit, X ',{.; b, spikelet, X 7; c, scale, X 23; d, 
achene, X 23. (Courtesy of R. K. Godfrey). 



including bracts) 1-7 cm. long, either of a single nearly sessile head or an umbel- 
like aggregation of 2 to 6 very unequal peduncles each bearing a head of more 
or less spreading spikelets, the total inflorescence with 5 to 38 spikelets; bracts 3 
to 5, the longer ones far-surpassing the inflorescence; spikelets 10-24 mm. long, 
2-3 mm. broad, laterally compressed, with 12 to 24 flowers, the axis persistent 
and remaining intact even after the achenes and scales have fallen; scales 3-3.5 
mm. long, acuminate, the keel-like median somewhat excurved in the distal half 
and with 9 to 13 nerves, grayish-white with very pale broad hyaline margins (so 
the entire spikelet appears to have a white mid-stripe), decurrent below as 
definite wings but these persistent until the scale next below falls; stamens 3; 
achene trigonous, 1-1.3 mm. long, almost as thick as long. 

In moist or wet sand and swampy ground, in Okla. (McCurtain Co.), in- 
frequent in s.e. Tex., rare in e. Tex., July-Sept.; Afr., Madag., s.e. Asia, Malaysia, 
N. Austral., Micronesia; in Am. from Ecu., Bol. and Braz. n. to N.Y., Pa., O., 
Okla. and Tex. 

30. Cyperus Parishii Britt. 

Perennial sedge with short rhizomes and fibrous roots; culms subtrigonous, 
smooth, 10-25 cm. tall; leaves several, much shorter than the culm, 3-5 mm. 
wide, minutely scabrellate on the margins and midrib; involucral leaves 3 or 4, 
scabrellate; inflorescence umbellate, the rays 0.5-5 cm. long; spikelets linear, 
acute, 12-20 mm. long, about 2 mm. wide; rachis with a pair of hyaline wings at 
each node, these early deciduous; scales ovate, acute, 2-3 mm. long, strongly 
several-nerved, the keel green and the sides reddish brown; stamens 3; style 
trifid; achene trigonous, obovoid-ellipsoid, 1-1.2 mm. long, mucronulate, nearly 
black. 

Wet meadows in N.M. (Dona Ana Co.) and Ariz. (Yavapai, Maricopa and 
Cochise cos.) ; N.M., Ariz, and Calif. 

31. Cyperus filiculmis Vahl. Fig. 231. 

Tufted or very loosely tufted perennial; culms basally tuberous-thickened or 
with short thick rhizomes, 10-35 (-50) cm. long, subbasally 1-2 (-2.3) mm. 
thick, just beneath the inflorescence 0.5-1 mm. thick; leaves 1-2 mm. broad, even 
the longer ones mostly shorter than the culms; inflorescence 1-3 cm. long, of a 
single nearly spherical head of 15 to 55 spikelets or (usually in contaminated 
plants) the inflorescences with such a head plus a few peduncles 1-5 cm. long 
each with a head or glomerule of 8 to 20 spikelets; bracts 3 or 4, 0.5-1 mm. 
broad, much-exceeding the inflorescence, usually spreading or reflexed; spikelets 
6-16 mm. long, 2.5-4 mm. broad, about 1 mm. thick, grayish-brown to dark- 
tawny-grayish-brown, with 7 to 20 scales (the terminal one sterile or staminate 
and slightly reduced), straight, the axis noticeably dorsiventrally flattened, at 
maturity either persistent or commonly tardily deciduous as a unit from the head 
axis, the flat sculptured internodes commonly wingless or with wings only to 0.2 
mm. broad; scales spreading at a 45° angle (the spikelet axis thus exposed), most 
much-overlapping, 2.5-3.5 mm. long, 2-2.5 mm. broad, broadly ovate, with 9 to 
11 nerves; stamens 3: achene 1.5-2.2 mm. long, 0.8-1.1 mm. thick, broadly 
oblong, trigonous, dark-brown. C. Houghtonii Torr. var. Bushii (Britt.) Kiikenth. 

Infrequent, scattered in seasonally moist sandy loam in open-wooded areas, 
wet sandy banks, in drying stream beds, in Okla. (Alfalfa Co.), n.-cen. Tex., 
Plains Country and Edwards Plateau, rare in the Trans-Pecos (i.e., genetically 
dilute plants in Glass Mts.), spring-fall; e. U.S. and s.e. Can. w. to the Rocky Mts. 

32. Cyperus elegans L. Fig. 232. 

Tufted perennial; culms 3-7 dm. long, erect; leaves viscid, crowded near the 
base, basally stramineous and somewhat spongy when fresh and upon drying the 

451 




Fig. 232: Cyperus elegans: a, habit, X V^; b, spikelet, X 5; c, scale, X 12; d, achene, 
X 14. (Courtesy of R. K. Godfrey). 




Fig. 233: Cyperus rotundas: a, ray, showing linear spikelets, X %; b, part of spike- 
let, 1 scale and wing removed to show wing on rachis continuous on either side of 
scale, X 12; c, scale, X 8; d, puncticulate trigonous achene, X 12; e, habit, showing 
the large umbellate inflorescence and short scabrellate involucral leaves, X %; f, spike- 
let, showing the very long filiform trifid styles, X 3; g, stolon with tubers, X %; h, 
flower, X 11. (From Mason, Fig. 132). 



incomplete septa becoming conspicuous, the upper part involute; inflorescence 
(excluding bracts) 5-15 (-22) cm. long, of 3 to 10 extremely unequal primary 
peduncles, the shorter ones each bearing a head of spikelets, the longer ones often 
with several short secondary peduncles each bearing a head; each head with 5 to 
13 spikelets; bracts 3 to 5, the longer ones much-exceeding the inflorescence; 
spikelets 3-15 mm. long, 2.5-4 mm. broad, with 6 to 20 flowers, viscid, grayish- 
ochraceous turning grayish-brown at maturity, the axis persistent and remaining 
intact even after the scales and achenes have fallen, wingless; scales firm. 3-4.2 
mm. long, with 3 strong nerves close together on the weakly keel-like median and 
farther apart on each side 2 or 3 less conspicuous ones (7 to 9 altogether), the 
very sharp tip slightly excurved, the lower sides not decurrent (the scales measured 
as folded in the spikelet is 1-1.2 mm. broad); stamens 3; achene 1.4-1.8 mm. 
long, black at maturity, trigonous, widest near the apex and long-tapered to the 
base. 

In moist calcareous soil, edge of lakes, ponds and tanks, and wet gravel-sand 
of creek beds, frequent in s.e. Tex. and Rio Grande Plains, infrequent to rare in 
Edwards Plateau and Trans-Pecos, Aug.-Nov., rarely in spring or early summer; 
W.I., Trin., C.A., Mex., Fla., La. and Tex.; a var. major Kukenth. in Peru. 

33. Cypenis oxylepis Steud. 

Tufted perennial; culms 3-7 dm. long, erect; leaves viscid, crowded near the 
base, basally stramineous splotched with red, somewhat spongy when fresh and 
upon drying the incomplete septa becoming conspicuous, the upper part involute; 
inflorescence (excluding bracts) 5-15 cm. long, of 3 to 10 extremely unequal 
primary peduncles, the shorter ones each bearing a head of spikelets. the longer 
ones often with several short secondary peduncles each bearing a head, each head 
with 6 to 18 spikelets; bracts 3 to 5, the longer ones much-exceeding the in- 
florescence; spikelets 8-22 mm. long, 2.5-3.5 mm. broad, with 10 to 24 flowers, 
viscid, grayish-yellow becoming at maturity a rich golden-brown, the axis persis- 
tent and remaining intact even after the scales and achenes fall, wingless; scales 
firm-membranous, 3.3-3.7 mm. long, with 3 strong nerves together on the weakly 
keel-like median and farther apart on each side 2 less conspicuous ones (7 
altogether), the sharp point very slightly excurved. the lower sides not decurrent 
on the axis (the half-scale measured as it is folded in the spikelet is 0.8 mm. 
broad); stamens 3; achene 1.4-2 mm. long, dark-brown at maturity, trigonous, 
nearly cylindric or very slightly thickened in the upper part and long-tapered 
below, capped by the beaklike persistent style base about 1 mm. long. 

Infrequent in coastal s.e. Tex. (Harris, Nueces, Refugio and San Patricio cos.) 
in clay ditches and ponds, May-Aug.; Arg., Parag., Ecu., Col., Br. Gui., Jam., 
Virg. I., Oax., Sin., Son., Tex. and La. 

34. Cypenis rotundus L. Nut-grass, tulillo. Fig. 233. 

Perennial forming colonies with creeping rhizomes about 1 mm. thick, at 
intervals with tuberlike thickenings to 1 cm. thick; culms 8-30 (-75) cm. long, 
just beneath the inflorescence 0.8-1.8 mm. thick; leaves crowded in the basal few 
cm., much shorter than the culm and usually spreading; inflorescence 3-11 cm. 
long, of 3 to 8 extremely unequal peduncles each hearing a (rarely compound) 
cluster or short spike of divaricate spikelets. each cluster or spike with 3 to 9 
spikelets, the total inflorescence with 20 to 65 spikelets; bracts usually about 3 or 
4 and about as long as the inflorescence; spikelets 4-30 mm. long. 1-2 mm. broad, 
laterally much-comnressed, with 12 to 36 flowers; scales keeled, straight, dark- 
reddish, dark-purplish or dark-purplish-brown, 3-3.5 mm. long, with about 7 
paler nerves crowded near the median so that each of the halves is nerveless in 
the marginal half to five eighths the width, the sides decurrent basally as hyaline 

454 




Fig. 234: Cyperus esculentus: a, ray, showing remote divaricate spilcelets, X %; b, 
spikelet, X 3; c, part of spikelet, with some flowers removed, showing the hyaline per- 
sistent wings of rachis, X 3; d, culm (cross section), X 2; e, stolons terminating in 
tubers, X %; f, ovate scale, showing mucronulate apex, X 8; g, habit, showing stolons, 
tubers, numerous flat leaves and umbellate inflorescences with broad ascending in- 
volucral leaves, X %; h, achene, showing surface puncticulate, X 12; i, flower, X 12. 
(From Mason, Fig. 131). 



|>ersistent wings on the spikelet axis which remains intact even after the scales and 
achenes have fallen; stamens 3; the prominent long-exserted anthers with the con- 
nective slightly prolonged into a minute reddish knob: achenes trigonous. 

Abundant in loamy soils, wet meadows and lawns, in Okla. (Waterfall), s.e., 
n.-cen. Tex. and Rio Grande Plains, rare in Plains Country and Trans-Pecos, a 
pernicious lawn-weed, adv. with us, July-Dec, less commonly Jan.-Apr.; wide- 
spread in the warmer parts of the world, nat. to Euras. 

35. Cyperus setigenis T. & H. 

Perennial forming small colonies with creeping rhizomes (1-) 1.5-5 mm. 
thick or slighly thicker at the culm bases; culms (60-) 75-110 cm. long, just 
beneath the inflorescence (1.5-) 2.3-3.3 mm. thick; leaves few, attached in the 
basal third of the culm, shorter than the culm, ascending; inflorescence (not in- 
cluding bracts) (7-) 10-16 (-20) cm. long, of 9 to 13 extremely unequal peduncles 
each bearing a compound cluster or short spike of divaricate spikelets, each cluster 
or spike with 10 to 30 spikelets, the total inflorescence with 120 to 350 spikelets; 
bracts about as many as the primary peduncles, the longer ones far-surpassing the 
inflorescence; spikelets 6-40 mm. long, 1.5-2 mm. broad, laterally much-com- 
pressed, with 6 to 40 flowers; scales keeled, reddish-brown, straight, 3-4 mm. long, 
with 5 to 7 nerves either crowded medially or somewhat spread out so that each of 
the halves is nerveless in the marginal fifth to three eighths the width, the sides 
decurrent basally as hyaline persistent wings on the spikelets axis which remains 
intact even after the scales and achenes have fallen; stamens 3; anther connective 
sometimes minutely prolonged achenes trigonous. 

Scattered and local in moist clay meadows and ditches, about lakes and ponds 
in Okla. (Comanche, Craig and Kay cos.), n.-cen. Tex., Rio Grande Plains, Ed- 
wards Plateau (Mason Co.) and Plains Country, summer; Kan., Mo., Okla. and 
Tex. 

36. Cyperus esculentus L. Yellow nut-grass. Fig. 234. 

Perennial forming colonies with creeping rhizomes 1-1.5 (-2) mm. thick (some 
forms have tuberlike thickenings on the rhizomes; these forms rarely flower); culms 
15-50 (-65) cm. long, just below the inflorescence 1.5-3 (-3.8) mm. thick; leaves 
several, attached in the basal half of the culm, the upper ones ascending, almost 
equaling or surpassing the inflorescence; inflorescence (not including bracts) 4-14 
(-24) cm. long, of 5 to 10 extremely unequal peduncles each bearing a short spike 
(or the longer peduncles a cluster of short spikes) of divaricate spikelets, each 
spike or cluster with 12 to 50 spikelets, the total inflorescence with 70 to 350 
spikelets; bracts about as many as the primary peduncles, the longer ones far- 
surpassing the inflorescence; spikelets 6-30 mm. long, 1-2 mm. broad, somewhat 
laterally compressed, with 8 to 40 flowers; scales keeled, straight, brown, buffy- 
brown or golden-brown, 2.6-4 mm. long, hyaline, with 7 to 9 nerves which are 
about equidistant and so spaced out that only about the marginal third of each 
side of the scale is nerveless, the sides decurrent basally as hyaline persistent 
wings on the spikelet axis which remains intact even after the scales and achenes 
have fallen; stamens 3; anther connective prolonged into a red dot 0.05-0.1 mm. 
long; achenes trigonous. Incl. var. angiistispicatus Britt. and var. macrostachyus 
Boeckl. 

Locally abundant and weedy in occasionally moistened sandy usually disturbed 
or unstable or loamy soil, in shallow water of ponds and lakes, gravel bars along 
streams and on seepage banks, in Okla. (LeFlore, Ottawa, Pushmataha and Alfalfa 
COS.), scattered all over Tex. but rare in Edwards Plateau and higher parts of the 
Plains Country, N. M. (widespread) and Ariz. (Apache, Navajo and Coconino, 
s. to Cochise, Santa Cruz and Pima cos.), summer-fall (through Dec. in extreme 

456 



s.); scattered in the warmer parts of the world, in Am. n. to Que., Ont., Minn., Ore. 
and Alas.; probably adv. in Tex. 

37. Cyperus strigosus L. Fig. 235. 

Tufted perennial (occasionally flowering the first year); culms 4-10 dm. long, 
subbasally 3-9 mm. thick (at the extreme base swollen tuberlike), just below the 
inflorescence trigonous and 1.7-3 mm. thick; leaves 2-8 mm. broad, firm, the 
longer ones about equaling the culm; inflorescence 7-30 (^0) cm. long, of 4 to 11 
very unequal primary peduncles the shorter of which bear spikes 13-25 mm. long 
and 2-4 cm. thick, each spike with 20 to 40 divaricately spreading spikelets in 
several ranks, the longer peduncles in turn bearing a few secondary peduncles 
(often very short) each with a spike 15-35 mm. long and 20-45 mm. thick, each 
spike with 25 to 70 spreading spikelets; bracts 3 to 10, the longer ones far-sur- 
passing the inflorescence; spikelets linear, straight, (10-) 12-25 (-29) mm. long, 
1-2 mm. broad, less than half as thick as broad, golden-brown or tawny-brown, 
with 5 to 20 scales (the terminal one sterile, tending to become involuted and 
forming a short point), the axis at maturity detaching as a unit from the spike axis, 
the internodes on the fertile side with 2 narrow hyaline wings 1 .5-2 mm. long, 
about 0.4 mm. broad; scales 3.7-4.5 mm. long, 1.2-1.8 mm. broad, with 7 or 9 
nerves, overlapping, usually persistent or less commonly belatedly deciduous either 
before or after the axis falls from the plant; stamens 3; achene 1.5-2 mm. long 
(usually about half as long as the scale), 0.5-0.6 mm. thick, trigonous, linear- 
oblong, brown, basally substipitate, short-apiculate. 

Frequent in bogs and marshy areas, in shallow water of ponds and lakes and 
in mud, in Okla. (McCurtain, LeFlore, Ottawa, Sequoyah, Craig, Johnston, Alfalfa 
and Mayes cos.), e. and s.e. Tex., less frequent in n.-cen. Tex. and rare in the 
Panhandle (genetically dilute plants rare elsewhere), and Ariz. (Pima Co.), 
summer-fall; e. U.S. n. to Que., Ont., Minn., w. to Neb., Kan., Okla. and Tex.; 
also Pac. States. 

38 Cyperus tenuis Sw. 

Tufted perennial; culms 3-8 dm. long, basally 2-7 mm. thick, just below the 
inflorescence 1.1-2.8 mm. thick; leaves 1.5-5 mm. broad, the longer ones about 
equaling the culms; inflorescence 6-20 cm. long, of 4 to 11 extremely unequal 
primary peduncles the shorter of which bear spikes 2-3 cm. long and 15-25 mm. 
thick, each spike with 14 to 30 divaricately spreading spikelets in 3 or 4 ranks, the 
longer peduncles each with a spike 25-40 mm. long and 18-27 mm. thick, each 
spike with 19 to 45 spikelets, the spikes occasionally compound with 1 or 2 smaller 
nearly sessile spikes basally; bracts 3 to 11, the longer ones far-surpassing the 
inflorescence; spikelets linear, straight, 10-15 mm. long, 0.7-1.3 mm. broad, about 
half as thick as broad, grayish-brown, with 3 to 6 scales (the terminal 1 sterile, 
tending to become involute and forming a short point), the axis at maturity de- 
taching as a unit from the spike axis, the internodes on the fertile side with 2 
narrow hyaline wings 1.5-2 mm. long and 0.3-0.5 mm. broad; scales 3.5-5 mm. 
long, 1-1.6 mm. broad, with 7 or 9 nerves, overlapping, persistent; stamens 3; 
achene 1.3-1.6 mm. long, less than half as long as the scale, 0.5-0.6 mm. thick, 
trigonous, ellipsoid to obovoid-ellipsoid, brown, very minutely stipitate, apiculate. 
Incl. var. lentiginosus (Millsp. & Chase) Kiikenth., C. strigosus var. gracilis Britt., 
C. lentiginosus Millsp. & Chase. 

Infrequent in s. part of s.e. Tex. (San Patricio and Nueces cos.) and coastal 
parts of Rio Grande Plains (Duval, Karnes and Cameron cos.), in wet or moist 
clayey loam, summer-fall; n. S.A. w. to C.A. and Mex., n. to Sin. and Tex.; also 
(?) Afr. 

457 






Fig. 235: Cyperus strigosus: a, part of a winged rachis, X 6; b, culm (cross sec- 
tion), X 5; c, scale, strongly nerved, X 12; d, linear puncticulate achene, with trifid 
style and 3 stamens, X 12; e, habit, showing corms swollen at base, the umbellate in- 
florescence and the involucral leaves which are unequal in length, X \-,; f, linear spike- 
lets, X 2'/;.; g, ray of inflorescence, showing loose divaricate cluster of spikelets, X %. 
(From Mason, Fig. 134). 



39. Cyperus huarmensis (H.B.K.) M. C. Johnst. 

(Often loosely) tufted perennial from black knotty subrhizomatous bases; culms 
1-4 dm. long, sub-basally 1.5-3 mm. thick, just beneath the inflorescence 0.7-1.3 
mm. thick; leaves 2-4 mm. broad, firm, shorter than the culms; inflorescence 2-3 
(-4) cm. long, of 3 to 6 essentially sessile (or occasionally 1 or 2 of them on 
peduncles 1-2 cm. long) dense spikes 10-25 mm. long and 7-10 mm. thick, with 
40 to 80 ascending spikelets; bracts 3 to 6, spreading, the longer ones 3 to 10 
times as long as the inflorescence; spikelets 4-7 mm. long, about 1 mm. broad 
and almost as thick, ochraceous gray-brown to tawny-gray, with 3 scales (usually 
only the lowest one fertile and it slightly longer than the others), straight, the axis 
at maturity detaching as a unit from the spike axis, the internodes of the fertile 
side with 2 hyaline wings 1.5-2.2 mm. long and 0.6-0.8 mm. broad, clasping the 
achene; fertile scale 3-4 mm. long, about 2 mm. broad, with about 9 nerves, 
almost completely overlapping the higher scales; stamens 3; achene 1.5-2.1 mm. 
long, 0.8-1 mm. thick, oblong-obovoid, trigonous, very dark-brown, substipitate, 
apiculate. C. cayennensis (Lam.) Britt., non Link, C. flavus (Vahl) Nees, non 
J. & C. Presl, Mariscus huarmensis H.B.K., C. obesus Liebm. 

Rare in s.e. Tex. (Aransas and San Patricio cos.) to Ariz. (Gila, Cochise, Pima 
and Santa Cruz cos.), spring-fall; widespread in the warmer parts of Am. s. to 
Arg. and n. to Ariz., N.M., Tex. and La. 

40. Cyperus Pringlei Britt. 

Perennial; culm erect, triangular, glabrous, to 6 dm. long, with swollen base 
from short nodose rhizomes; leaf sheaths thin, subscarious, yellowish to reddish- 
brown, to 12 cm. long; leaf blades flat, 3-8 mm. wide, glabrous or slightly scabrous 
along the midrib and margins, to 3 dm. long; bracts 5 to 8, to 2 dm. long, sur- 
passing the inflorescence; umbels simple or somewhat compound of 5 to 6 rays, 
1-12 cm. long, spreading; spikes cylindric-oblong, rather loose, 7-10 mm. in 
diameter, 1.5-3 cm. long; spikelets terete-oblong, 1 mm. in diameter or less, 3-5 
mm. long, 3- to 5-flowered; scales pale yellow to light-brown, 2.2-2.5 mm. long, 
1.5-2 mm. wide, distinctly 7 to 11 -nerved; rachilla scariously winged; stamens 3; 
style deeply 3-cleft; achenes ellipsoid-oblong, trigonous, basal one-third of margin 
enfolded by scarious rachilla wings, olive-brown, sublustrous, minutely punctate. 

Canyons, wet meadows and mt. slopes in Ariz. (Pima Co.), Aug.-Sept.; also 
Chih. and Son. 

41. Cyperus hermaphroditus (Jacq.) Standi. 

Tufted perennial; culms very slightly thickened, 15-80 cm. long, sub-basally 
1-3 mm. thick, just below the inflorescence 0.7-2 mm. thick; leaves 1-3 mm. 
broad, the longer ones about as long as the culm; inflorescences 3-15 cm. long, 
of 4 to 8 or more slender very unequal peduncles each with a lax spike 1-3 cm. 
long and 1-2 cm. thick, of 8 to 30 or more divaricately spreading spikelets in 3 or 
4 ranks, secondary peduncles absent; bracts 3 to 8, the longer ones far-surpassing 
the inflorescence; spikelets linear, 5-1 1 mm. long, 0.5-1 mm. broad, more than 
half as thick as broad, dull-brown, with 3 to 7 scales (the terminal one sterile, 
tending to become involute and forming a short point), the axis at maturity detach- 
ing as a unit from the spike axis, the internodes on their fertile side with 2 narrow 
hyaline wings 1.3-2 mm. long and 0.3-0.5 mm. broad; scales 2.5-3.5 mm. long, 
0.8-1.3 mm. broad, with about 9 nerves, overlapping, persistent; stamens 3; achene 
1.6-1.8 (-2) mm. long, 0.6-0.8 mm. thick, trigonous, oblong to ellipsoid, yellow- 
ish-brown to brown, substipitate, apiculate. Incl. var. angustior (Clarke) Kukenth., 
C thyrsiflorus Schlecht. & Cham., C. dissitiflorus Torr. 

Rare in rich loam, shaded river woods, s.e. Tex. (Brazoria, Colorado, Harris 
and Jackson cos.), and Ariz. (Pima Co.), summer; widespread in warmer parts of 
Am., n. to Ala., La., Tex., Coah. and Ariz. 

459 




Fig. 236: C\perus oviilaris: a, habit, X %; b, spikelet, X 5; c, spikelet, X 15; d, 
achene, X 15. (Courtesy of R. K. Godfrey). 



42. Cypenis ovularis (Michx.) Torr. Figs. 236 and 237. 

Tufted perennial; culms, basally with tuberous enlargements, 25-80 cm. long, 
sub-basally 1-3 mm. thick, just beneath the inflorescence 0.6-2 mm. thick; leaves 
1.5-5 mm. broad, the longer ones about equaling the culms; inflorescence (1-) 
3-12 cm. long, of (1 to) 3 to 8 very unequal peduncles each with a dense spherical 
or prolate-spherical head 7-19 mm. long and 7-18 mm. thick, with (70 to) 100 to 
240 spikelets borne spirally or in many ranks, about equally dense at top and 
bottom, the upper spikelets ascending, middle ones spreading and lower ones 
retrorsely appressed; secondary peduncles absent; bracts (2 or) 3 to 7, the longer 
ones far-exceeding the inflorescence; spikelets 3.5-9 mm. long, 0.5-1 mm. broad, 
about half to three fourths as thick as broad, straw-brown to dark-brown, with 2 to 
4 scales ( the terminal one or two sterile and forming a blunt point, not an awn), 
straight, the axis at maturity detaching a unit from the head axis, the internodes on 
the fertile side with hyaline wings 1-2 mm. long and 0.3-0.7 mm. broad, usually 
not clasping the achene; fertile scales 2.5-4mm. long, 1.2-2 mm. broad, obtuse, 
with about 9 nerves well-distributed over the width, overlapping, persistent; stamens 
3; achene narrowly oblong, 1.8-2.2 mm. long, 0.5-0.7 mm. thick, trigonous, brown 
substipitate, apiculate. Inc. var. sphaericus Boeck. and var. robustus Britt., C. 
Wolfii Wood. 

Infrequent in moist or wet sand, wet soil on edge of lake and banks of ditches, 
in Okla. (Carter, Pittsburg, Pushmataha and LeFIore cos.), e., s.e. and n.-cen. Tex., 
spring-fall; e. U.S. n. to N.Y., Pa., O., Ind., 111. and Mo., w. to Kan., Okla. and 
Tex. 

The description above applies to the typical form. A more common form is the 
var. cylindricus (Ell.) Torr. (C. retrorsus Chdipva.) with narrower and proportion- 
ally more elongate heads (actually short spikes), paler and with a slightly more 
tawny-ochraceous tinge, with fewer spikelets on the average (50 to 100), only 2 or 
3 scales per spikelet, the wings averaging slightly narrower, the wings, scales and 
achene averaging shorter. 

43. Cyperus globulosus Aubl. Fig. 238. 

Tufted perennial; culms slightly tuberous-enlarged basally, 1-8 dm. long, sub- 
basally 1.5-2.5 mm. thick, just beneath the inflorescence 1-1.7 mm. thick; leaves 
1.5-3 mm. broad, the longer ones about equaling the culms; inflorescences 2-8 
cm. long, of 3 to 14 very unequal peduncles each with a dense head 7-15 mm. long 
and 8-17 mm. thick, with 25 to 70 spikelets borne spirally or in a number of ranks, 
about equally dense throughout, the upper spikelets ascending, the middle ones 
spreading, the lower spreading or slightly descending but never retrorsely appressed; 
secondary peduncles absent; bracts 4 to 11, the longer ones far-exceeding the inflor- 
escences; spikelets 5-10 mm. long, 0.7-1.3 mm. broad, almost as thick as broad, 
greenish-brown to ochraceous-brown or olive, with 3 to 8 scales (the terminal one 
sterile or staminate and forming a short point, or blunt), straight, the axis at 
maturity detaching as a unit from the head axis, the internodes with hyaline wings 
0.8-1.4 mm. long and 0.25-0.6 mm. broad and not clasping the achene; scales 
2.5-3 mm. long, 1-1.3 mm. broad, obtuse, with usually 9 well-distributed nerves, 
overlapping, persistent; stamens 3; achene narrowly oblong, 1.3-1.6 mm. long, 
about 0.6 mm. thick, trigonous, brown, substipitate, subapiculate. 

Frequent in moist or dry sandy soil, wet clay meadows and wet depressions, 
in Okla. [Waterfall), e. and s.e. Tex., rare and in genetically dilute from inland 
to n.-cen. Tex., summer-^fall; n. reputedly to Va. and Mo. 

10. Cladium P. Br. 

About 55 species of tropical and temperate regions, especially Australia; our 
species almost cosmopoHtan. 

461 





Fig. 237: Cyperus ovularis var. cyliiidricus: 
achene, X 15. (Courtesy of R. K. Godfrey). 



a, habit, X iV, b, spikelet, X 10; c, 




Fig. 238: Cyperus globulosus: a, habit, X 1/2; b, spikelet, X 5; c, scale, X 15; d, 
achene, X 15. (Courtesy of R. K. Godfrey). 



1. Cladium jamaicense Crantz. Saw-grass. Fig. 239. 

Coarse erect reed 1-2.5 m. tall, with short rhizomes; leaves long, very tough, 
channeled ventrally, with dangerous saw-toothed cutting margins; inflorescences 
ample, 2-5 dm. long, much-branched, often droopy; spikelets ovoid, chestnut- 
brown, 3-5 mm. long, in fascicles of 2 to 6 at ends of the branchlets, each with a 
single fertile floret and below it 2 or 3 other spirally imbricate scales, all but the 
lowest enclosing stamens; perianth absent; achene obovoid, apiculate, somewhat 
lustrous, brownish, the obovoid body 2-2.5 mm. long, the apiculate 0.6-1 mm. 
long. 

Locally abundant in fresh water on margins of streams, ponds and lakes, mostly 
in areas of calcareous soil, s.e. Tex., Rio Grande Plains, Edwards Plateau and 
Trans-Pecos, summer; widespread in Carib. region, n. to Gulf States and Va. The 
var. chinense (Nees) Koyama occurs in China and Japan. 

Most of the plants of Arizona, Nevada and New Mexico, and some plants of the 
Edwards Plateau and the Trans-Pecos, Texas, have, on the average, slightly smaller, 
proportionately shorter and more numerous spikelets and denser inflorescences than 
the plants described above. These have been segregated as a separate species, C. 
californicum (Wats.) O'Neill. These differences are not well marked but usually 
the plants from the above states, California and Coahuila are thought to be C. 
californicum. 

11. Schoenus L. 

About 100 species, world-wide in distribution. 

1. Schoenus nigricans L. Black sedge. Fig. 240. 

Coarsely tufted perennial; culms slender, wiry, erect, simple, 2-6 dm. long, 
about 1 mm. thick; leaves basally crowded, the lower sheaths chestnut-black and 
shiny, the upper blades tough, thin, wiry, involute, shorter than the culms, apically 
spinose; bracts 1 or 2, the lower one far-surpassing the inflorescence, involute and 
wiry like the leaves; inflorescence a single sessile glomerule of about 10 sessile 
spikelets; spikelets laterally compressed, of about 5 to 10 distichous much-overlap- 
ping dark-chestnut to blackish scales of which only the upper few produce mature 
fruit; perianth bristles few, much shorter than the achene, minutely plumose at the 
very base; style 3-branched; achene shortly obovoid-trigonous with convex sides, 
pearly- or bony-white, shiny, jointed abruptly with the difl"erently-textured style 
which thus does not leave a tubercle. 

Infrequent or rare in creek canyons, about hot springs and other wet places, s. 
part of Tex. Edwards Plateau, spring; widespread in warm-temp, usually semiarid 
parts of the world. 

12. Dichromena Michx White-top Sedge 

Tufted or rhizomatous perennials with stems leafy basally, the blades ascending; 
flowering culms terminating in an involucrate headlike agglomeration of spikelets, 
the bracts white basally but green distally; spikelets usually whitish; scales several, 
spirally imbricated or irregularly distichous, the terminal ones enclosing a fertile 
floret, the lower ones staminate or empty; perianth absent; achenes lenticular, 
transversely rugose, crowned with the broad persistent base of the style (tubercle) 
as in Rhynchos-pora. Some authors would include Dichromena within Rhyncho- 
spora. 

One of the more easily recognizable of the sedges because of the white bases of 
the bracts; these apparently function to attract insects. Most sedges, on the con- 
trary, are thought to be wind-pollinated. About 60 species in the Western Hemi- 
sphere. 

464 




Fig. 239: Cladium jamaicense: a, top of plant, X W, h, base of plant, X V2; c, 
central part of culm and sheath, X 1/2; d, section of leaf, X II/2; e, achene, about X 12. 
(Courtesy of R. K. Godfrey). 




Fig. 240: Schoenus nigricans: a, habit, X Vi;; b, scale, X 15; c, achene, X 15. 
(Courtesy of R. K. Godfrey). 



1. Plants densely tufted; rhizomes absent; culms 1 mm. or less thick; blades 3-7 
cm. long, 1 mm. broad basally, arcuate-filiform in the distal part; 
bracts 2 (rarely 3), the longer ones 17-37 mm. long, filiform most 
of the length 3. D. nivea. 

1. Plants with extensively creeping orangish or whitish rhizomes; culms 1.5-3 

mm. thick basally; blades 6-25 cm. long, 1.2-4 mm. broad basally 
and at least 1 mm. broad even in the distal part; bracts several, the 
longer ones (20-) 40-130 mm. long, not filiform except perhaps 
at the extreme apex (2) 
2(1). The white spot at the base of the longer bracts 5-20 (-25) mm. long, a 
(third to a) fifth to a tenth as long as the bracts; bracts 3 to 6 
(or 7) 1. D. colorata. 

2. The white spot at the base of the longer bracts 25-50 mm. long, about half as 

long as the bracts; bracts 6 to 10 2. D. latifolia. 

1. Dichromena colorata (L.) Hitchc. White-topped umbrella grass. Figs. 241 

and 242. 

Rhizomes usually orangish, 2-3 mm. thick, extensively creeping, scaly; culms 
12-56 cm. long, erect or often decumbent at the very base; leaves crowded basally, 
mostly rather stiffly ascending, 2-6 mm. broad, linear-involute at the tip; bracts 
3 to 6 (or 7), mostly basally ascending but for the most of the length spreading 
or slightly reflexed, lanceolate, very unequal, the longer ones (3-) 5-15 cm. 
long, (1.5-) 2.5-5 mm. broad basally, with a white spot 5-20 (-25) mm. long. 

Locally frequent in swales, ditches and wet places generally, s.e. Tex., Rio 
Grande Plains and Edwards Plateau, rare in s. part of e. Tex., w. to Terrell Co. 
in the Trans-Pecos, (spring-) summer widespread in Carib. region, n. to Va. and 
the Gulf States; e. Mex. 

2. Dichromena latifolia Ell. Figs. 241 and 242. 

Perennial with rhizomes 2-3 mm. thick; culms rather stiffly erect the full 
length, 4-8 (-10) dm. long, 2-4 mm. thick basally; leaves crowded basally, ascend- 
ing, 4-6 mm. broad basally, tapered upward and involute in the distal third, 
apically pointed; bracts 6 to 10 mostly basally ascending but for most of the 
length spreading or slightly reflexed, lanceolate, very unequal, the longer ones 
5-10 cm. long, 4-10 mm. broad in the lower half, with a white spot 25-50 mm. 
long (about half as long as the bract) . 

Locally frequent in poorly drained pine savannahs, s.e. Tex (Hardin and 
Jefferson cos. only), summer; Gulf States and n. to N.C. 

3. Dichromena nivea (Boeck.) Britt. Fig. 241. 

Densely tufted; rhizomes absent; culms weak, ascending, 1-3 (-4) dm. long, 
about 1 mm. thick or less; leaves in the lower part, flaccid, 3-7 cm. long, about 
1 mm. broad basally, arcuate-filiform; bracts 2 (rarely 3), weak, the longer ones 
17-37 mm. long, filiform most of the length, with a white spot only at the very 
base, D. Reverchonii S. H. Wright, Rhynchospora nivea Boeck. 

Locally frequent in creek beds through limestone on Tex. Edwards Plateau, 
rare in n.-cen. Tex. and Okla. (Marshall Co.), summer; also Ark. 

13. Rhynchospora Vahl (corr. Willd.) Beak-rush 

Perennials (rarely annuals); culms leafy; inflorescence of each culm usually 
divided into several discontinuous parts (branches of the culm), the largest part 
(appearing terminal) usually subumbelliform (occasionally much-reduced) with 
several unequal primary branches (each subtended by a bracteal leaf) and these in 
turn bearing spikelets or glomerules or corymbs of spikelets; the several axillary 
parts of the inflorescence below usually reduced as compared to the terminal part, 

467 




Fig. 241: a, Dichromena latifnlia: a, inflorescence, X l/l>. b-e. Dichromena nivea: 
b, habit, X \-y\ c, spikclet pulled apart to show flowers, X 5; d, flower with scales re- 
moved, X 5; e, achene, X 5. f-h, Dichromena colorala: f, habit, X 1/2; g, spikelet, X 5; 
h, achene, X 5. (V. F.). 





Fig. 242: a, Dichromena colorata: a, achene, X 25 b, Dichromena latifolia: b, 
achene, X 20. (Courtesy of R. K. Godfrey). 



occasionally reduced to virtual absence; spikelets with several spirally-disposed 
scales, the axils of the lowest 1 (or 2) scales empty, the 1 to 10 axils above with 
perfect flowers, and usually above that 1 or 2 scales enclosing staminate or rudi- 
mentary flowers; scales usually broad, membranous, usually brownish with very 
indistinct midnerves and no other nervation; bristles usually above 6 or 8 (or up 
to 20) or reduced to virtual absence; stamens usually 1 or 2 or 3; style bifurcate 
either at the very tip or usually much farther down, its base becoming indurate 
and persisting on the achenial body as a tubercle of distinctly difl'erent texture; 
achenial body usually distinctly biconvex, varying to nearly flat or nearly turgid, 
the cells of the face usually variously sculptured and elongated, the walls often 
prominent. 

About 200 species, cosmopolitan in distribution, especially tropical. The name 
has been misspelled as Rynchospora and Rhyncospora in various works. 
1. Style nearly simple or very shortly 2-branched at the summit; achenial bodies 
3.5-6 mm. long; tubercle 3.5-18 mm. long (2) 

1. Style with 2 long branches; achenial bodies and tubercles mostly shorter (4) 

2(1). Mature spikelet 7-10 mm. long; achenial body 3.5-4 mm. long; tubercle 
3.5-4 mm. long 3. R. indianolensis. 

2. Mature spikelet 15-23 mm. long; achenial body 4—5 mm. long; tubercle 13-18 

mm. long (3) 

3(2). Bristles (at least most of them) much-exceeding the achenial body..... 

1. R. macrostachya. 

3. Bristles shorter than the achenial body, stout and closely appressed 

2. R. corniculata. 

4(1). Achenial bodies pearly-white, 0.7-0.8 mm. long; tubercles 0.1-0.2 mm. 
long, 0.15-0.2 mm. broad; spikelets with 5 to 8 fertile flowers; 
perianth bristles absent (5) 

4. Achenial bodies and/ or tubercles considerably larger and often brownish in 

color; spikelets with fewer fertile flowers; perianth bristles usually 
present (6) 



469 



5(4). Achenial body smooth under low magnification or faintly cellular-reticulate 

under high magnification, the 2 faces strongly convex 

4. R. divergens. 

5. Achenial body with transverse ridges, the 2 faces only sHghtly convex 

5. /?. piisilla. 

6(4). Bristles conspicuously retrorsely barbed (7) 

6. Bristles antrorsely barbed or plumose or absent or smooth (10) 

7(6). Bristles 10 to 20 per achene; spikelets with only 1 fertile flower and this 
appearing terminal (no rudimentary flower above it); inflorescence 
usually merely a dense terminal fascicle 9. R. macra. 

7. Bristles fewer; spikelets usually with 2 fertile flowers or one fertile flower and 

a reduced one above it; each culm with several fascicles, one 
terminal and several axillary, or if only one fascicle then culm 
capillary (8) 

8(7). Culms capillary; achenes inconspicuously margined, finely granulate to 
slightly rugulose, achene body 1.7-2.6 mm. long, less than half 
as wide as long 6. R. capillacea. 

8. Culms 1-3.5 mm. thick basally; achenes with conspicuous pale vdre-like 

margins, smooth, castaneous, usually lustrous, achene body 1.3-1.7 
mm. long, one half to three fourths as wide as long (9) 

9(8). Central portions of the 2 sides of the achenial body abruptly raised in a 
hump and polished-buff'y, contrasting with the dark chestnut-brown 
submarginal flat portions, the margins themselves pale and wirelike; 

leaves basally 5-6 mm. broad; culms basally 2-3.5 mm. thick 

7. R. glomerata. 

9. The 2 sides of the achenial body rather evenly convex all over, grading from 

buffy centrally to darker brownish marginally, the margins them- 
selves slightly paler and wirelike; leaves basally 2-3 mm. broad; 
culms basally 1-2 mm. thick 8. R. capitellata. 

10(6). Bristles heavily plumose basally (11) 

10. Bristles antrorsely serrulate or barbed, smooth or these absent (12) 

11(10). .Spikelets 4-7 mm. long, 1 to 5 present per culm, remote on slender 

pedicels; achene 2.3-2.6 mm. long (excluding tubercle) 

10. R. oUganthra. 

1 1 . Spikelets 3-4 mm. long, more numerous, congested in spikelike fascicles; 

achene 1.4-1.8 mm. long (excluding tubercle) 11. R. plumosa. 

12(10). Achenial body smooth (13) 

12. Achenial body with traverse wrinkles or traverse rows of cells with 

sculptured walls (15) 

13(12). Achenial body 0.9-1 mm. long; tubercle 0.4-0.6 mm. long 

12. R. fiUfolia. 

13. Achenial body 1 .3-1 .8 mm. long; tubercle 0.4-2 mm. long (14) 

14(13). Tubercle 0.4-0.7 mm. long 13. R. fascicularis. 

14. Tubercle 1-2 mm. long 14. R. gracilenta. 

15(12). Terminal part of inflorescence of each culm very lax, with only 6 to 12 
(to 20) spikelets each on a capillary pedicel 3-12 mm. long; culms 
only 0.6-1 mm. thick 17. R. rariflora. 

15. Terminal fascicle denser with more spikelets or if as few as 12 then either 

denser or else the culm thicker than 1 mm. basally (16) 

470 



16(15). Horizontal rows of cells counted in vertical series near the middle of 
one face of the achenial body numbering (14 to) 16 to 30 and 
all the cells nearly isodiametric, the horizontal cell walls only 
slightly if at all raised more than the vertical walls; achenes turgid, 
1 mm. or more thick from the middle of one face to the middle 
of the other (17) 

16. Horizontal rows of cells usually 11 to 15; (except in R. mixta) those cells 

near the middle of the face greatly vertically elongated and their 
horizontal walls very prominent and forming horizontal wrinkles on 
the achene, but those cells near the base and top of the body 
nearly isodiametric; achenes less turgid, less than 1 mm. thick from 
face to face (18) 

17(16). Achenial body 2-2.4 mm. long, 1.5-1.8 mm. thick from face to face; 
horizontal rows of cells 25 to 30 or more; spikelets 4-5.5 mm. 
long 15. R. Grayi. 

17. Achenial body 1.5-1.8 mm. long, 1-1.5 mm. thick from face to face; hori- 

zontal rows of cells (14 to) 16 to 20; spikelets 2.5-3 mm. long 

16. R. Harveyi. 

18(16). Achenial body twice as long as broad 18. R. inexpansa. 

18. Achenial body less than twice as long as broad (19) 

19(18). Bristles (most of them) surpassing the tubercle (20) 

19. Bristles not surpassing the tubercle (22) 

20(19). Achenial body 1.2-1.3 mm. long, the 2 faces nearly flat; plants never 
rhizomatous; tubercle 0.3-0.4 mm. long 20. R. Elliottii. 

20. Achenial body 1.3-1.7 mm. long, the 2 faces distinctly convex at least in the 

upper part; plants rhizomatous (this often obscure in exsiccatae); 
tubercle 0.4-0.9 mm. long (21) 

21(20). Achenial body only 0.8-0.9 mm. broad, with numerous indistinct trans- 
verse lines 19. R. mixtra. 

21. Achenial body 1.2-1.6 mm. broad, with strong transverse wrinkles 

23. R. caduca. 

22(19). Primary branches of the terminal part of the inflorescence straight, 
stiffly ascending; faces of the achenial body definitely convex at 
least in the upper half 24. R. globularis. 

22. Primary branches of the terminal part of the inflorescence arcuate, often 

slightly droopy; faces of the achenial body nearly flat or only very 
slightly convex (23) 

23(22). Bristles half as long as to nearly as long as the achenial body; Wades 
usually flat basally 21. R. microcarpa. 

23. Bristles less than half as long as the achenial body; blades usually nearly all 

strongly involute 22. R. perplexa. 

1. Rhynchospora macrostachya Torr. Horned-rush. Fig. 243. 

Tufted perennial; culms 5-10 dm. long, erect, 3-7 mm. thick basally, trique- 
trous, leafy; basal sheaths becoming markedly fibrous; inflorescence (at maturity) 
clavate, 3-6 cm. thick, the branches numerous but rather short, erect; spikelets 
subulate, rich-brown, 15-23 mm. long, the distal third consisting merely of the 
protruding distal part of the tubercle; bristles; several (4 to 7), about 1.5 to 2.5 
times as long as the achenial body, stiff, brownish, antrorsely barbed; achenial 
body 4-5 mm. long, obovate, nearly flat on the 2 faces, dark-brown; tubercle 
subulate, consisting of the indurated entire portion of the style, 13-18 mm. long, 
pale-brownish to buffy. R. corniculata var. macrostachya (Torr.) Britt. 

471 




Fig. 243: a-c, Rhynchospnro corniculata: a, terminal inflorescence. X il-; b, flower, 
X 2V:.; c, achene, X V/^. d-f, Rhymhospora nuicrostachya: d, upper part of plant, X V-z', 
e, achene, X IV-,; f, flower, X 2V>. (V. F.). 



In mud about ponds and along ditches, and in and on edge of lakes, infrequent 
in s.e. Tex., rare in e. Tex., and Okla. (LeFlore, Atoka and Pushmataha cos.), 
summer; s.e. U.S. n. to N.E., N.Y. and Mo., w. to Kan., Okla. and Tex. 

2. Rhynchospora corniculata (Lam.) Gray. Horned-rush. Fig. 243. 
Perennial, either tufted or usually with thick scaly rhizomes (these often broken 

off in specimens); culms 6-1 1 dm. long, erect, 3-9 mm. thick basally, triquetrous, 
very leafy; basal sheaths becoming only slightly fibrous; inflorescence at maturity 
loose-obovoid, ample, 7-15 cm. thick, the numerous branches ascending to spread- 
ing; spikelets subulate, rich-brown, 15-23 mm. long, the distal third to half 
consisting merely of the protruding distal part of the tubercle; bristles 2 to 4 
(or 5), about a third to two thirds as long as the achenial body, stiff, brownish, 
closely appressed; achenial body 4-5 mm. long, obovate, nearly flat on the 2 faces, 
dark-brown; tubercle subulate, consisting of the indurated entire portion of the 
style, 13-18 mm. long, pale buffy. 

Frequent in mud, on edge of lakes, along edge of swamps and in water of 
ditches, in Okla. (Choctaw, McCurtain, Bowie, LeFlore and Sequoyah cos.), e. and 
s.e. Tex., spring-summer, (fruiting into fall); s.e. U.S., n. to Del., Ky., Ind. and 
Mo., w. to Okla. and Tex.; W.L 

Ours are nearly all of the var. interior Fern, in which the achenial body is 
only about 1.5 times as broad as the base of the tubercle; a few are of the var. 
corniculata in which the body is about twice as broad as the tubercle. 

3. Rhynchospora indianolensis Small. 

Tufted perennial; culms 5-9 dm. long, erect, 3-6 mm. thick basally, trique- 
trous, leafy (especially in the basal part); terminal part of the inflorescence some- 
what umbelliform, Cyperus-Vike, 4-9 cm. long, with several ascending rays each 
bearing a dense roundish glomerule or capitulum of nearly sessile spikelets, usually 
a reduced axillary part of the inflorescence present; spikelets 7-10 mm. long, 
lanceolate, brown, acute, the tubercle only slightly if at all exserted; bristles 3 to 5, 
about equaling the achenial body, stiff, appressed; achenial body 3.5-4 mm. long, 
obovate, nearly flat on the 2 faces, dark brown; tubercle 3.5-4 mm. long, brown, 
elongate-deltoid, acute or slightly acuminate. 

Locally frequent in mud, s.e. Tex., summer; endemic. 

4. Rhynchospora divergens M.A. Curtis. 

Tufted short-lived perennial (or annual?); culms 18-42 cm. long, 0.3-0.9 mm. 
thick, erect; leaves numerous, 5-10 cm. long, setaceous-involute; terminal part 
of the inflorescence umbel-like, 1-2 cm. long, and 1 cm. broad, occasionally 
1 or 2 reduced axillary parts of the inflorescence present below; spikelets linear, 
3- to 10-flowered, about 1 mm. thick, the fruits very quickly maturing in suc- 
cession acropetally as the spikelet elongates, the scales and achenes falling as the 
achenes mature, eventually as many as 5 to 8 fruits maturing from a single spikelet 
but only 1 or 2 visible at any one time; scales brownish, about 1.5 mm. long; 
bristles absent; achenial body 0.7 mm. long, obovate, white, the 2 faces convex 
and under low magnification appearing smooth, under higher magnification faintly 
cellular-reticulate; tubercle about 0.15 mm. long and 2 mm. broad, whitish, blunt. 

Rare in moist or wet sand, s.e. Tex. (Aransas and Montgomery cos.), summer; 
S.C., Ga., Fla., Bah. L and Tex. 

5. Rhynchospora pusilla M. A. Curtis. 

Tufted short-lived Bulhostylis-Mke perennial; culms 15-30 cm. long, 0.2-0.7 
mm. thick, erect; leaves numerous, 5-10 cm. long, setaceous-involute, terminal 
part of the inflorescence reduced, somewhat umbel-like or corymbose, 6-20 mm. 
long, 5-10 mm. broad, often reduced parts of the inflorescence also present from 

473 




Fig. 244: Rhynchospora glomerata: a, top of plant, X V-y, b, scale, X 25; c, achene, 
X 15. (Courtesy of R. K. Godfrey). 



the penultimate axils; spikelets, linear, 3- to 10-flowered, about 1 mm. thick, the 
fruits very quickly maturing in acropetal succession and falling with the scales, 
as many as 5 to 8 fruits maturing from a single spikelet but only 1 or 2 visible 
at any one time; scales brownish, about 1.5 mm. long; bristles absent; achenial 
body 0.7-0.8 mm. long, obovate, whitish, the 2 faces nearly flat, with transverse 
rugae; tubercle 0.1-0.15 mm. long, 0.15-0.2 mm. broad, whitish, blunt. 

Rare in moist or wet sand, s. part of e. Tex. (Hardin Co.), summer; Fla. to 
Tex.; W.I. 

Some authors have referred these plants to R. intermixta Wright. 

6. Rhynchospora capillacea Torr. 

Tufted perennial; culms capillary, 1-4 dm. tall; leaves filiform, 0.2-0.4 mm. 
wide, often as long as the inflorescence; inflorescence ellipsoid or ovoid, of 
1-10 spikelets, the terminal 2-8 mm. broad, the 1 axillary fascicle subsessile or 
short, peduncled; spikelets lanceolate, sessile or subsessile, brown, 5-7 mm. long, 
1- to 5-fruited; scales with a pale margin; bristles 6 (or rarely more), retrorsely 
barbed, as long as or longer than the tubercle; achenes obovate-oblong, marked 
horizontally or rugose, 1.7-2.6 mm. long, less than half as wide, narrowed toward 
the base; tubercle lanceolate, 0.8-1.6 mm. long. 



474 



In calcareous meadows or calcoreous swamps and seepage areas, reported 
from Bryan Co., Okla. by Waterfall; Nfld. to Sask., s. to N.J., Pa., Va., Tenn., 
Mo., Okla. and S.D. 

7 Rhynchospora glomerata (L). Vahl. Fig. 244. 

Tufted perennial; culms 6-11 dm. long, erect, 2-3.5 mm. thick basally, tri- 
quetrous, leafy; larger leaves 5-6 mm. broad near the base of the plant; inflores- 
cence variable, either of a number of subcapitate glomerules scattered along the 
upper half of the culm ("var. glomerata") or a few more discretely grouped 
glomerules ("var. angusta Gale"): spikelets lanceolate, 4.5-6 mm. long, rich- 
dark-brown, with usually 2 fruits (less commonly 3 or 1, if wath 1 then with a 
terminal rudimentary flower); bristles about 6, exceeding the achene and often 
about equaling the tubercle, somewhat dorsiventrally compressed, conspicuously 
retrorsely barbed; achenial body pyriform, 1.5-1.7 mm. long, the 2 sides with an 
abruptly raised central hump which is polished and buffy, contrasting with the 
dark-chestnut-brown submarginal flat portion, the margins themselves pale like the 
umbo; tubercle 1.3-1.8 mm. long, elongate-deltoid, much compressed, grayish. 

In moist sand, wet sandy drainage area, ponds on edge of woods, in water of 
seepage bog, in Okla. (LeFlore, McCurtain, pushmataha and Pittsburg cos.), 
frequent in e. Tex., infrequent in s.e. Tex., summer; Gulf States, n. to Del., Va., 
Tenn. and Ark., w. to Okla. and Tex. 

8. Rhynchospora capitellata (Michx.) Vahl. Fig. 245. 

Tufted perennial; culms 2-9 dm. long, erect, 1-2 mm. thick basally, bluntly 
3-angled, leafy; larger leaves 2-3 mm. broad near the base of the plant; inflores- 
cence of a few turbinate fascicles scattered along the uppor half of the culm; 
spikelets lanceolate, 3.5-5 mm. long, usually with 2 fruits (less commonly 3 or 1, 
if with 1 then also with a terminal rudimentary flower); bristles about 6, exceeding 
the achene, usually about equaling the tubercle, somewhat dorsiventrally com- 
pressed, conspicuously retrorsely barbed; achenial body pyriform or obovate, 
basally cuneate, 1.3-1.6 mm. long, the 2 sides merely convex (the central portions 
paler, grading off into the darker brown submarginal zones, the margins themselves 
pale like the center); tubercle elongate-deltoid, 0.9-1.6 mm. long, grayish, much- 
compressed. 

On banks of streams and spring branches and wet places in uplands, infrequent 
or rare in Okla. (Adair and McCurtain cos.) and e. Tex. (Austin, Guadalupe, 
Angelina, Henderson and Leon cos.), apparently always in acid boggy ground, 
summer; e. U.S. n.e. to N.S., w. to Wise, Mo., Okla. and Tex. 

9. Rhynchospora macra (Clarke) Small. Fig. 245. 

Tufted (?) or with rhizomes about 1 mm. thick; culms 3-7 dm. long, erect, 
triquetrous, 1.5-2 mm. thick near the base; leaves several, the blades 2-3.5 mm. 
broad near the base of the plant; inflorescence primarily a large terminal turbinate- 
corymbose fascicle 1-3 cm. broad, 1 or 2 extremly reduced axillary fascicles 
also present; spikelets linear-lanceolate, 4-5 mm. long, pale brown, each with a 
single fertile flower and never a higher rudimentary one; bristles 10 to 20 per 
achene, much-surpassing the body, conspicuously retrorsely barbed; achenial body 
pyriform 1.8-2 mm. long, brown (the raised central portions of the 2 sides paler, 
buffy), the submarginal surfaces with very faint transverse wrinkles; tubercle 
elongate-deltoid, much-compressed, about 1 mm. long. 

Very rare in bogs in e. Tex. (Houston and Robertson cos.), summer; Ga., Fla., 
Miss, and Tex. 

475 





k 










■-"4 



Fig. 245: a-c, Rhynchospora capitellata: a, top of plant. X V.; b, scale, X 15; c, 
achene, X 15. d-g, Rhynchospora nuura: ci, top of plant. X I.e. scale, X 15; f. achene 
with usual bristles, X 15; g, achene with unusual smooth bristles, X 15. (Courtesy of 
R. K. Godfrey). 




Fig. 246: a-c, Rhynchospora oUgantha: a, top of plant, X 1; b, scale, X 15; c, 
achene, X 15. d-f, Rhynchospora phmiosa: d, top of plant, X 1; e, scale, X 25; f, 
achene, X 25. (Courtesy of R. K. Godfrey). 



10. Rhynchospora oligantha Gray. Fig. 246. 

Tufted perennial; culms 15-45 cm. long, erect or ascending, 0.3-0.6 mm. 
thick; leaves filiform-setaceous, resembling the stems; inflorescence of a lax 
terminal fascicle and usually a remote reduced axillary one, each fascicle with 
only 1 to 3 spikelets; spikelets on slender individual pedicles 3-10 mm. long, 
narrowly ovoid, pale-brown, 4-7 mm. long, usually with 2 fruit (1 to 3); bristles 
6, in the lower half densely plumose, slightly shorter than the body; achenial 
body 2.3-2.6 mm. long, broadly ovate, dark-brown when mature, very turgidly 
biconvex, transversely wrinkled, apically prounoncedly narrowed into a definite 
hour-glassed-shaped turbercle base, tubercle very short-conic, 0.3-0.6 mm. long. 

Rare in bogs and open seepage slopes, in e. Tex. (Austin, Henderson, Smith 
and Waller cos.), spring (May-early June); N.J., Del., N.C., Ga. and Gulf States; 
Gr. Ant.; C.A. 

11. Rhynchospora plumosa Ell. Fig. 246. 

Tufted perennial; culms wiry, 2-4 dm. long, erect, 0.6-1.1 mm. thick, basally, 
stamineous; leaves setaceous-filiform, numerous, often curling toward the ends; 
lower bracts of the fascicles elongate, wiry, like the leaves, far-surpassing the 
inflorescence; inflorescence compact, congested, terminal, 1-3 cm. long, about 
1 cm. thick, often spikelike; spikelets pale- to dark-brown, lance-elliptic, 3-4 mm. 
long, usually with 1 or 2 fruits; bristles 6, densely plumose in the lower part; 
achenial body broadly obovate, 1.4-1.8 mm. long, brown, turgid, transversely 
wrinkled, not narrowed apically; tubercle short-conic, about 0.5 mm. long, brown. 
R. semi plumosa Gray. 

Infrequent in wet soils along streams and in savannah-evergreen shrub bogs, 
in s.e. Tex. (Hardin, Tyler and Newton cos.), Apr.-May; coastal flats, N.C. to 
Tex.; Cuba. 

12. Rhynchospora filifolia Gray. Fig. 247. 

Tufted perennial; culms 3-6 dm. long, about 1 mm. thick near the base, erect, 
wiry; leaves mostly involute, resembling the culms; inflorescence a terminal very 
dense round-topped fascicle 10-15 mm. broad, plus usually one reduced fascicle 
in the next lowest axil; spikelets cinnamon-brown, lanceolate, 3-5 mm. long, with 
3 to 10 flowers, the 2 to 6 achenes and their scales quickly falling in acropetal 
succession, upon maturation only 1 or 2 mature achenes present at any one time 
and these usually exposed by the rapid shedding of the scales; bristles 6, usually 
surpassing the tubercle, minutely antrorsely barbed; achenial bodies obovate, 
0.9-1 mm. long, biconvex, the 2 polished smooth faces brown or the central por- 
tions paler, buffy, tubercle deltoid, grayish, compressed, acute, 0.4-0.6 mm. long. 

Rare in moist loam and wet areas in savannahs, in e. Tex. (Hardin and Waller 
COS.), summer; coastal areas, N.J. to Tex.; Cuba. 

13. Rhynchospora fascicularis (Michx.) Vahl. Fig. 248. 

Tufted perennial; culms 5-13 dm. long, 1.5-2.5 mm. thick basally, subterete 
or obtusely 3-angled, leafy; leaves 1-4 mm. broad; inflorescence a crowded 
terminal group of 1 to 3 fascicles (about 1 cm. broad and overtopped by the 
setaceous bracts) plus usually 1 (rarely 2) remote similar axillary fascicles below; 
spikelets 3.5-5 mm. long, lanceolate, cinnamon-brown, several-flowered and 
-fruited, the scales caducous in acropetal succession, each falling just before 
maturation of its achene; bristles about 6, minutely antrorsely serrulate or barbed; 
achenial body nearly orbicular, biconvex, very dark-brown or fuscous except for 
a buff'y spot in the center of each of the 2 smooth faces, 1.4-1.5 mm. long; 
tubercle deltoid, 0.4-0.7 mm. long, much-compressed, grayish. 

478 




Fig. 247: Rhynchospora filifolia: a, top of plant, X P^; b, scale, X 40; c. achene, 
X 40. (Courtesy of R. K. Godfrey). 




ig. 248: a-c. Rhvnchospora gracilcnta: a, top of plant, X V2; b, scale, X 15; c, 
;ne, X 15. d-f. Rhynchospora fascicularis: d, top of plant, X IVy, e, scale, X 25; f, 



F 

achene 

achene, x 25. (Courtesy of R. K. Godfrey) 



Infrequent in moist sand, savannahs and bogs in pinelands, in s.e. Tex. 
(Arkansas, Tyler, Chambers and Jefferson cos.), summer; low coastal areas, Va. 
to Tex.; Berm., Gr. Ant. 

14. Rhynchospora gracilenta Gray. Fig. 248. 

Tufted perennial; culms 5-9 dm. long, erect, 1-1.5 mm. thick basally, essen- 
tially terete; leaves mostly confined to the base of the plant, the blades proximally 
only 1-2.5 mm. broad, distally involute; inflorescence a terminal fascicle about 
1 cm. broad and usually a remote slightly smaller axillary one a few cm. below; 
spikelets broadly lanceolate, 3-4 mm. long, cinnamon-brown, with 2 or 3 flowers, 
when 3 flowers present usually only the middle one or the upper 2 bearing fruit; 
bristles about 6, about equaling the body or tubercle, minutely antrorsely serru- 
late or barbed; achenial body broadly obovate or nearly orbicular, turgidly 
biconvex, 1.3-1.8 mm. long, smooth, dark-brown (or a central spot on each of 
the 2 faces slightly paler); tubercle much-compressed, whitish, 1-2 mm. long 
including the straplike prolongation. 

Infrequent in boggy ground and pitcher plant bogs, e. and s.e. Tex., summer 
(-fall?); s.e. U.S. mainly near the coast, N.J. to Tex., less frequent inland to 
Tenn. and Ark. 

15. RhjTichospora Grayi Kunch. Fig. 249. 

Tufted perennial; culms 4-7 dm. long, 1.5-2 mm. thick basally, erect; leaves 
mostly crowded toward the base, curly, 2-4 mm. broad; inflorescence a dense 
terminal fascicle about 1 cm. broad and long, of essentially sessile spikelets, plus 
sometimes a reduced fascicle lower down; spikelets cinnamon-brown, 4-5.5 mm. 
long, narrowly ovoid to broadly lanceolate, of 2 to 3 flowers, but usually maturing 
only 1 fruit; bristles 6, minutely antrorsely serrulate; achenial body broadly 
obovate, 2-2.4 mm. long, 1.8-2.2 mm. broad, 1.5-1.8 mm. thick from face to 
face, turgid, at maturity dark-brown, each face with 25 to 30 or more horizontal 
rows of minute nearly isodiametric cells whose horizontal walls are only slightly 
more prominent than the verticle walls; tubercle conic, 0.4-0.6 mm. high, basally 
not wider than (but often appearing embedded in) the top of the body. 

Rare in moist or wet sand, e. Tex. (Jasper and Liberty cos.), Mar.-May 
(earlier-flowering than most beak-rushes); lowlands near the coast, Va. to Tex.; 
Cuba. 

16. Rhynchospora Harveyi W. Boott. Fig. 250. 

Tufted perennial; culms 15-60 cm. long, 1-2 mm. thick near the base, erect, 
obtusely triquetrous, leafy; leaves 1.5-3 mm. broad; inflorescence a dense terminal 
fascicle about 5 mm. high and 5-10 mm. broad, of essentially sessile spikelets 
plus usually 1 or 2 reduced similarly dense glomerules lower down; spikelets 
cinnamon-brown, ovoid, 2.5-3 mm. long, usually with 2 flowers and setting 1 
fruit; bristles 6, minutely antrorsely serrulate achenial body broadly obovate, 
1.5-1.8 mm. long, 1.3-1.6 mm. broad, 1-1.5 mm. thick from face to face, turgid, 
at maturity rick-dark-brown, each face with (14 to) 16 to 20 horizontal rows of 
minute nearly isodiametric cells with prominent walls; tubercle conic, 0.4-0.5, mm. 
long, basally no wider than (but often appearing embedded in) the top of the 
body. R. Plankii Small. 

Frequent to abundant in low places in open woods and prairies, wet soils on 
edge of streams, e., s.e. and n.-cen. Tex., and Okla. (Pushmataha Co.), Apr.- 
Sept.; s.e. U.S. n. to Va., Tenn. and Mo., w. to Okla. and Tex. 

17. Rhynchospora rariflora (Michx.) Ell. Fig. 251. 

Tufted perennial; culms 3-6 dm. long, 0.6-0.9 mm. thick near the base, 
ascending but often flexuous, essentially trete; leaves in lower half of plant, 

481 




Fig. 249: a-c, Rhynchospora Grayi: a. top of plant, X 1 : b, scale, X 12; c, achene, 
X 12. d-f, Rhymhospora cadiica: d, top of plant, X V-S, e, scale, X 25; f, achene, X 25. 
(Courtesy of R. K. Godfrey). 




Fig. 250: a-c, Rhynchospora mixta: a, top of plant, X %; b, scale, X 25; c, achene, 
X 25. d-f, Rhynchospora Harveyi: d, top of plant, X 1; e, scale, X 25; f, achene, X 25. 
(Courtesy of R. K. Godfrey). 



capillary-setaceus; inflorescence of a terminal 6- to 12- (to 20-) spikeletted 
lax subumbelliform unit 1-3 cm. broad, the individual capillary pedicels 3-12 mm. 
long; spikelets narrowly ovoid, subacute, pale-cinnamon-brown, 3-4 mm. long, 
with 2 to 4 flowers and maturing 1 to 3 fruits: bristles 6, shorter than the achenial 
body, minutely antrorsely serrulate; achenial body broadly obovate, 1.1-1.4 mm. 
long, biconvex, pale-brown, the 2 faces with strong transverse ridges, tubercle 
deltoid, compressed, 0.3-0.6 mm. long. 

Rare in bogs or piny crayfish-land, savannahs, e. and s.e. Tex. (Austin, Harris, 
Henderson, Anderson, Tyler, Leon, Orange and Waller cos.) May-June; coastal 
areas, N.J. to Tex.; also Tenn., Gr. Ant. and C.A. 

18. Rhynchospora inexpansa (Michx.) Vahl. 

Tufted perennial; culms 5-8 dm. long, erect (or terminally drooping), wiry, 
1.5-2 mm. thick near the base; leaves mostly basal, with long tough somewhat 
curly blades; inflorescence fairly narrow, elongate and drooping; spikelets lanceo- 
late, brown, 4.5-6 mm. long, with 2 to 5 flowers, setting 1 to 4 fruits; bristles 
about 6, surpassing the tubercle, minutely antrorsely serrulate; achenial body 
elliptic-obovate, 2-2.2 mm. long, 0.8-1 mm. broad, much-compressed, the 2 flat 
faces transversely rigid; tubercle deltoid, 0.9-1.2 mm. long. 

Locally frequent in open pinelands, swamps, ditches, marches, in ponds, 
savannahs and pineland bogs, e. and s.e. Tex. (Angelina, Hardin, Jasper, Jefferson 
and Liberty cos.), summer; Coastal States, Va. to Tex.; also Ark. and (?) Okla. 

19. Rhynchospora mixta Small. Fig. 250. 

Rhizomatous perennial; culms about 1 m. long, about 2 mm. or more thick 
basally, leafy, erect or ascending (flexuous in the distal floriferous portion); 
blades 3-4 mm. broad; inflorescence decomposed, open, the terminal portion 
3-4 cm. broad, very lax, of about 25 spikelets, some of the ultimate glomerules 
on long spreading arculate-erect peduncles 10-15 mm. long; spikelets narrowly 
ovoid, 4-6 mm. long, brown, with 2 or more (rarely as many as 10) flowers, 
1 (rarely as many as 10) fruit produced; bristles about 6, surpassing the tubercle, 
upwardly minutely barbed; achenial body narrowly obovate, 1.3-1.4 mm. long, 
0.8-0.9 mm. broad, turgidly biconvex, with very numerous faint transverse lines; 
tubercle deltoid-attenuate, 0.4-0.9 mm. long, compressed. 

Rare in sandy forested areas near streams, e. Tex. (Nacogdoches Co.), summer; 
near the cost, N.C. to s.e. La.; Tex. 

20. Rhynchospora Elliottii A. Dietr. 

Tufted perennial; culms 8-15 dm. long, 2.5-5 mm. thick basally, erect except 
slightly nodding distaliy; leaf blades 4-5 mm. wide basally, mostly long-tapered, 
strictly erect and appressed; inflorescence of 2 to 5 dense decomposed separate 
portions, the terminal portion irregularly corymbiform, 2-6 cm. broad, of 150 to 
300 spikelets; spikelets ovoid, rich-dark-brown, 2.5-3.2 mm. long, with 3 to 6 
flowers and setting 2 to 4 fruits; bristles 6, surpassing the tubercle, minutely 
antrorsely serrulate, not closely appressed to the achene but slightly spreading 
basally and arcuate-erect; achenial body obovate, tawny-brown, 1.2-1.3 mm. long, 
0.9-1.1 mm. broad, with very pronounced traverse ridges on the 2 nearly flat 
faces; tubercle deltoid, 0.3-0.4 mm. long. R. schoenoides (Ell.) Wood, an illegit. 
name. 

Frequent in moist or wet sand in savannahs, in e. and s.e. Tex., summer; near 
the coast, N.C. to Tex. (except Fla.) 

21. Rhynchospora microcarpa Gray. Fig. 251. 

Tufted perennial; culms 5-8 dm. long, 2-3 mm. thick basally, erect; leaves 
mostly appressed or curly, 2-3 mm. broad basally; inflorescence in (1 or) 2 to 4 

484 





Fig. 251: a-c, Rhynchospora microcarpa: a, top of plant, X 1; b, scale. X 25; c, 
achene, X 25. d-f, Rhynchospora rariflora: d, top of plant, X i/^; e, scale, X 25; f, 
achene, X 25. (Courtesy of R. K. Godfrey). 




Fig. 253: a-c, Rhyncliospora glohularis: a. top of plant, X ij; b, scale, X 25; c, 
achene, X 25. d-f, Rlivnchospora pcrplexa: d, top of plant, X 1; e, scale, X 30; f, 
achene. X 30. (Courtesy of R. K. Godfrey). 



parts per culm, the terminal part irregularly corymbiform, dense, nearly erect, 
2-6 cm. broad, of 100 to 200 spikelets or less commonly fewer; spikelets ovoid to 
narrowly ovoid, 2.5-3 mm. long, dark-rich-brown, with 3 or 4 flowers and setting 
2 or 3 fruits; bristles about 6, from half as long as to as long as the body or 
rarely nearly equaling the tubercle, stiffly erect and mostly appressed to the body, 
minutely antrorsely serrulate; achenial body obovate, 1-1.2 mm. long, 0.8-1.2 
mm. broad, the 2 nearly flat or very slightly convex faces with strong transverse 
wrinkles; tubercle deltoid, 0.2-0.5 mm. long. 

Rare in moist or wet sand, s.e. Tex. (Aransas Co.), summer; near the coast, 
Fla. and Ga. to Tex.; Bah. I., Hisp. and Cuba. 

22. Rhynchospora perplexa Small. 

Tufted perennial; culms 5-11 dm. long, 1.5-2 mm. thick basally, wiry, erect 
or very slightly flexuous in the floriferous region; leaf blades 1-2 mm. broad 
basally, mostly strongly involute; inflorescence in 1 to 3 parts per culm, the 
terminal part very irregularly cormbiform, 1-4 mm. broad, usually dense and with 
upwards of 100 to 200 spikelets; spikelets ovoid, rich-dark-brown, 2.5-3 mm. 
long; bristles about 6 or fewer, less than half as long as the body to which they are 
appressed or reduced to virtual absence; achenial body obovate, 1-1.3 mm. long, 
0.9-1.2 mm. broad, tawny, the 2 nearly flat or very slightly convex faces with 
strong transverse wrinkles; tubercle deltoid, 0.2-0.3 mm. long. 

Rare in moist or wet sand in e. and s.e. Tex. (Aransas, Hardin, Tyler and 
Waller cos.), late spring-summer; Coastal States, s.e. Va. to Tex.; Tenn.; Gr. Ant. 

Probably not specifically distinct from R. microcarpa. 

23. Rhynchospora caduca Ell. Fig. 249. 

Rhizomatous perennial; culms 7-13 dm. long. 2-4 mm. thick near the base, 
ascending but quite flexuous in the upper part; leaves 4-7 mm. broad below the 
middle, tapering in both directions; inflorescence of 3 to 5 parts per culm, the 
terminal part obovoid, irregularly corymbiform, 2-4 cm. broad, with 60 to 125 
spikelets, some of the primary branches commonly elongate, erect and 1-2 cm. 
long; spikelets rich-dark-brown, ovoid, 4-4.5 mm. long, with 3 to 6 flowers and 
setting 2 to 5 fruits; bristles about 6, surpassing the tubercle and somewhat stiffly 
spreading away from the body basally, minutely antrorsely serrulate; achenial 
body obovate, 1.4-1.7 mm. long, 1.2-1.6 mm. broad, the 2 faces with strong 
transverse wrinkles and at least in the upper part pronouncedly convex; tubercle 
deltoid, 0.6-0.8 mm. long. 

Frequent in moist or wet sand in Okla. (McCurtain Co.) and s.e. Tex. (Liberty 
and Polk cos.), less frequent in e. Tex. (Bowie Co.) and very local in Burnet 
and Llano cos. on the Edwards Plateau, summer; Coastal States, Va. to Tex.; 
also Ark. and Okla. 

24. Rhynchospora globularis (Chapm.) Small. Fig. 253. 

Tufted perennial; culms (15-) 30-75 (-90) cm. long, 1-1.8 (-2.5) mm. thick 
near the base, basally often shortly reclining, mostly erect, leafy with the old 
sheaths basally becoming somewhat fibrous; blades 1.5-4 mm. broad; inflorescence 
in 1 to 4 parts per culm, the terminal part usually strictly erect, of several 
straight stiffly ascending unequal branches each topped by a corymbiform 
glomerule 8-15 mm. broad (broader than high) and often with stiffly erect 
setaceous protruding bracts; spikelets ovoid, 2.5-4 mm. long, cinnamon-brown, 
with 1 to 4 flowers and setting 1 to 3 fruits; bristles about 6, shorter than the 
body of the achene, minutely antrorsely serrulate; achenial body obovate, 1.2-1.6 
mm. long, 1-1.5 mm. broad, castaneous, with 2 faces which are convex at least in 
the upper part and have strong transverse wrinkles; tubercle deltoid, 0.3-0.6 mm. 

487 




fjy 



JM 

'I 




Fig. 254: Psilocarya nitens: a, habit, X i/n; b, sheath, X 3; c, spikelet, X 5; d, 
achene, X 25. (Courtesy of R. K. Godfrey). 



long. R. cymosa of many auth., not (Willd.) Ell., R. glohularis var. recognita 
Gale, R. obliterala Gale. 

Moist sandy soil, bogs, seepage areas, ditches, wet coastal savannah-prairie, 
in Okla. (McCurtain, Sequoyah and Pushmataha cos.), frequent in e. Tex., 
infrequent in s.e. Tex. and rare inland to n.-cen. Tex., late spring-summer; wide- 
spread in s.e. U.S., n. to N.J., Tenn. and Mo., w. to Okla. and Tex.; also Calif., 
W.I. and C.A. 

14. Psilocarya Torr. Bald Rush 

An American and Australian genus of about 6 species, included by several 
workers in Rhynchospora. 

1. Psilocarya nitens (Vahl) Wood. Fig. 254. 

Said to be annual but occasionally with weak short rhizomes and often rooting 
from the lower nodes; culms few, erect, soft, 3-8 dm. long, 1-4 mm. thick, usually 
with 1 to 3 weakly exserted ascending branches in the middle part; leaves crowded 
in lower half of culm, with long acute ascending blades; main panicle lax, terminal 
on main stem, smaller panicles terminating the branches; bracts several, attached 
at close intervals along the panicle axis, shorter than the inflorescence; inflorescence 
axis about 1 cm. long, with several unequal divergent mostly naked branches 
bearing racemes of spikelets; spikelets 5-9 mm. long, narrowly ovoid, acute; 
scales numerous, spirally attached, strongly imbricate, brown, ovate, acute, all 
fertile; perianth absent; style branches 2; base of style becoming indurated and 
persistent on the achene as a low grayish tubercle almost as broad as the achene 
itself (but not as thick); achene plumply biconvex, Rhynchospora-\\k&, strongly 
transversely wrinkled. 

Infrequent or rare, usually in marshy places, in mud at edge of water and on 
vegetation mats in lakes, in s.e. Tex. (Hardin, Houston and Madison to Aransas 
COS.); coastwise, Mass. to Tex.; local in n.w. Ind. 

15. Scleria Berg. Stone-rush. Nut-rush 
About 200 species, mostly tropical and subtropical. 
1. Scleria Muhlenbergii Steud. Fig. 207. 

Annual with fibrous roots or perennial with very short rhizomes; culms 15-80 
cm. long. 1-1.6 mm. thick, trigonous or somewhat compressed, tufted, weak and 
diffuse; sheaths sometimes somewhat winged; blades 15-25 cm. long, 1-4 (-8) 
mm. broad, flat, often with cartilaginous margins, sometimes scabrous marginally 
and on the nerves beneath; inflorescence terminal and axillary (the lateral ones 
very remote, on long setaceous-filiform compressed often recurved or drooping 
peduncles), loosely flowered, the clusters 1-3 cm. long; spikelets 2-4 mm. long; 
hypogynium deeply 3-lobed, the lobes ovate-lanceolate, subacute, appressed; 
achene 2 mm. long, more or less reticulate, the transverse ridges pilose, sordid- 
white, globose-elliptic, umbonate, the ridges somewhat spirally disposed. S. setacea 
of many auth., non Poir. 

Moist sand, about lakes, edge of water, pitcher plant bogs, pineland bogs, and 
seepage slopes, infrequent in e. Tex. (Angelina, Tyler and Henderson cos.), rare 
in n. part of Rio Grande Plains (Guadalupe Co.); N.Y. to Ind. and s. to Gulf 
States; W.I., Mex., C.A., s. to Braz. and Bol. 

16. Carex L. Sedge. Caric-sedge 

Perennials with well-developed leaves, mostly monoecious; inflorescence of 
several to many more or less spikelike spikelets emerging singly from the axils 
of the upper leaves (herein called bracts) (in C leptalea the spikelet solitary), in 
some species the spikelets so numerous and crowded and the bracts so reduced 

489 



that the inflorescence appears headlike or spikelike; spikelets of few to many uni- 
sexual flowers arranged spirally around the axis (rarely in definite rows) either 
wholly staminate or pistillate or androgynous (with staminate flowers at top, pistil- 
late below) or gynecandrous (reverse order); staminate flowers comprising merely 
3 stamens (rarely 2) subtended by a scale; pistillate flowers merely a scale sub- 
tending a "perigynium" that encloses an achene; perigynium an indehiscent bag 
or envelop completely enclosing the achene (but not adherent to it) except at 
the minute apical orifice through which the stigmas protrude at anthesis, falling 
with the mature achene and thus a spurious outer portion of the fruit which is 
unique to this genus. 

An enormous, technical genus occurring in moist temperate and moist cool 
tropical regions. Carex is in dire need of critical taxonomic study bolstered by 
cytology and by field and garden studies which might elucidate many of the 
problems arising from hybridization or introgression. The keys and descriptions 
can be used only when the material to be determined is complete with under- 
ground parts and has fully mature achenes, the latter to be examined carefully at 
a magnification of at least 15 diameters. 

Presumably caric-sedges provide some forage for stock. 

(Part of treatment adapted from F. J. Hermann "Manual of the Carices of the 
Rocky Mountains and Colorado Basin." Agr. Handb. No. 374, Forest Service, 
U.S. Dept. Agric. 1970). 

1. Achenes lenticular or plano-convex; stigmas 2 (2) 

1. Achenes trigonous; stigmas 3 (43) 

2(1). Terminal spike androgynous or gynecandrous (except C. Douglasii which 
is dioecious); lateral spikes short and sessile (3) 

2. Terminal spike staminate, (rarely gynecandrous or androgynous); lateral 

spikes peduncled or elongate and sessile (35) 

3(2). Some or all spikes androgynous, not gynecandrous (or plants dioecious) 
(4) 

3. Some (especially the terminal) or all spikes gynecandrous, with staminate 

flowers at base or scattered, not at apex (15) 

4(3). Rhizomes slender, elongating; culms mostly solitary; spikes (at least the 
lower) distinct (5) 

4. Rhizomes short, not freely stoloniferous, with short internodes; culms or leafy 

tufts approximate (8) 

5(4). Plants dioecious or nearly so; perigynium beak nearly as long as the body 
1. C. Douglasii. 

5. Plants not dioecious, the spikes mostly androgynous; perigynium beak shorter 

(6) 

6(5). Perigynia plump, unequally biconvex, rounded to the summit with fine 
nerves on both surfaces, white-punctate 4. C. disperma. 

6. Perigynia broadly ovate to ovate-lanceolate, nerveless or nearly so, winged 

(7) 

7(6). Perigynia yellowish, brown to chestnut-brown, 1.7-2.7 mm. long, hyaline- 
winged at the center; rootstock and lower sheaths light-brown 

2. C. simulata. 

7. Perigynia brownish-black, 3-4 mm. long, thin-coriaceous with sharp coriaceous 

margins; rootstocks blackish, fibrous 3. C. praegracilis. 

8(4). Spikes 2 to 15 in an ovoid, bractless head, 10-15 mm. long and 4-9 mm. 
thick 6. C. cephalophora. 

8. Spikes numerous, in paniculate spikelike heads, usually 2 to several on each 

lateral branch (9) 

490 



9(8). Leaf sheaths close; blades firm; culms slender and firm; perigynia firm, flat 
or merely convex on inner surface (10) 

9. Leaf sheaths loose; blades soft to firm; culms soft, flattened under pressure; 

perigynia spongy or corky at base, thin and soft, more or less 
inflated (13) 

10(9). Inner nerveless ventral band of leaf sheath not cross-puckered; perigynia 

broadly compressed, obovoid or obpyramidal, abruptly beaked 

7. C. decomposita. 

10. Inner nerveless ventral band of leaf sheath cross-puckered and/ or red-dotted; 

perigynia flat on inner face (11) 

11(10). Leaves flat, exceeding the culm; perigynia ascending, 1.7-3 mm. long; 
scales, ovate, the 3-nerved center green, terminating in a long 
rough awn 8. C. vulpinoidea. 

11. Leaves thickish, flat or channeled, usually not exceeding the culm; perigynia 

ascending or spreading, 3.5-4 mm. long; scales acute or cuspidate 
(12) 

12(11). Perigynia 1.6-1.8 mm. wide, almost black at maturity; achenes 1.5 mm. 
long (Ariz.) 9. C. alma. 

12. Perigynia 2 mm. wide, light-green or brown; achene 2 mm. long (Okla.) 

10. C. fissa. 

13(9). Bases of perigynia disklike; beak 2 to 3 times length of body 

11. C. crus-corvi. 

13. Bases of perigynia not disklike; beak 1 to 2 times length of body (14) 

14(13). Leaf sheaths cross-puckered ventrally, without band at the orifice 

12. C. stipata. 

14. Leaf sheaths smooth ventrally, with band at the orifice.... 13. C. laevivaginata. 

15(13). Perigynia with rounded to very narrow margins or edges, without def- 
inite winged margins, thickened or corky at the base (16) 

15. Perigynia with thin or winged margins, mostly with concave inner faces, not 

spongy or corky at the base (20) 

16(15). Perigynia with rounded margins, ascending or merely spreading-ascend- 
ing, of soft or membranaceous texture (17) 

16. Perigynia with thin but scarcely winged margins, ascending to horizontally 

divergent or reflexed in maturity, firm, very spongy at base (19) 

17(16). Perigynia ovoid-oblong, 1.8-3 mm. long, more or less nerved on both 
surfaces; beak very short or obsolete 5. C. canescens. 

17. Perigynia ovate-lanceolate or lanceolate, 3.5-4.5 mm. long; beak half the 

length of the body (18) 

18(17). Perigynia shallowly bidentate, 3.5-4 mm. long; spikes ovoid or oblong, 
the lateral pistillate 14. C. leptopoda. 

18. Perigynia deeply bidentate, 4-4.5 mm. long; spikes linear-oblong, all gyne- 

candrous 15. C Bolanderi. 

19(16). Beak of perigynia only minutely notched; perigynia 1-2 mm. wide, 
nerveless or essentially so; heads 1-3 cm. long, of subglobose spikes 
about 4 mm. in diameter 16. C. interior. 

19. Beak of perigynia sharply bidentate at tip; perigynia 2-2.5 mm. wide, strongly 

nerved on both surfaces; heads 2-6 cm. long, of 3 to 6 echinate 
spikes mostly 7-12 mm. long and 6-8 mm thick 17. C. atlantica. 

20(15). Spikes 1.5-2.5 cm. long, long-cylindric; perigynia 7-10 mm. long, thin 
and scalelike 18. C. muskingumensis. 

20. Spikes less than 1.5 cm. long; perigynia less than 7.7 mm. long (21 ) 

491 



21 (20) . Perigynia at most 2 mm. wide (22) 

21. Perigynia more than 2 mm. wide (28) 

22(21). Bracts conspicuously exceeding the head but not leaflike 

19. C. athrostachya. 

22. Bracts wanting or setaceous (23) 

23(22). Perigynia barely distended over the achene, thin and scalelike (24) 

23. Perigynia obviously distended over achene, firm (26) 

24(23). Sheaths loose and loosely ribbed, veined ventrally with a hyaline summit; 
wings of perigynia abruptly narrowed above the base (Tex. and 
Okla.) 20. C. tribuloides. 

24. Sheaths close, ventrally hyaline; wings of perigynia extending continuously 

to the base (Ariz. & N.M.) (25) 

25(24). Perigynia 3.5-5 mm. long; beak of perigynium slender and terete, not 
serrulate (or only slightly) at the usually dark-colored tip; spikes 
distinguishable but aggregated into an ovoid or suborbicular trun- 
cate-based head 21. C microptera. 

25. Perigynia 4-7 mm. long; beak of perigynium flattened and serrulate to the 

pale tip; spikes aggregated into an oblong or linear-oblong head 

22. C. scoparia. 

26(23). Perigynia ovate, broadest below the middle; spikes often clavate at base.. 
23. C. festiicacea. 

26. Perigynia obovate to suborbicular or elliptic to rhombic, broadest at or above 

the middle (27) 

27(26). Inflorescence 6-10 mm. thick; spikes ovoid, each with 30 to 50 perigynia 

which are 2.8-3.2 (-3.5) mm. long and 1.6-2.2 mm. broad 

24. C. alholutescens. 

27. Inflorescence 12-15 mm. thick; spikes narrowly ovoid, each with 55 to 80 

perigynia which are (3-) 3.5-4.2 (-4.5) mm. long and 1.7-2.5 
mm. broad 25. C. Longii. 

28(21). Scales acute to blunt, without awn-tips (29) 

28. Scales awn-tipped; body of perigynium broadest near the summit 

26. C. alata. 

29(28). Perigynia thin and scalelike, barely distended over the achene, lanceolate 
to narrowly ovate, 1.2-2.6 mm. wide 22. C. scoparia. 

29. Perigynia firmer and thicker, usually well-distended over the achene (30) 

30(29). Beak of perigynium short and broad, gradually tapering into the firm 
broadly elliptic to rhombic body of the perigynium which is 3-4.5 
mm. long and 1.7-2.5 mm wide 25. C Longii. 

30. Beak of perigynium elongate and narrow above, more abruptly difTerentiated 

from the obovate or suborbicular body of the perigynium which is 
3.5-7.7 mm. long (31) 

31 (30). Perigynia pale-green to dull-brown. 2.8-3.5 mm. long, 1.6-2.2 mm. wide, 

the obovate to suborbicular bodies broadest above the middle 

24. C. alholutescens. 

31. Perigynia stramineous or greenish, 3.5-8.5 mm. long, 2.3-6 mm. wide, the 

bodies broadest below the middle (32) 

32(31). Perigynia strongly nerved on ventral surface (33) 

32. Perigynia ventrally essentially nerveless or nerves few (34) 

33(32). Perigynia 15 to 30 per spike, broadly ovate, with transverse wrinkles 
between the veins on the ventral side; perigynia 2.5-3.2 mm. wide.... 
27. C. hyalina. 

492 



33. Perigynia more numerous per spike, ovate, broadly winged, nerved dorsally 

and ventrally; perigynia 2.7-4.8 mm. wide 28. C. Bicknellii. 

34(32). Larger perigynia (including beaks) 5.5-8.5 mm. long 

29. C. Brittoniana. 

34. Larger perigynia (including beaks) 2.8-5.5 mm. long 30. C. reniformis. 

35(2). Bracts long-sheathing; perigynia golden-yellow or whitish-pulverulent at 
maturity (36) 

35. Bracts nearly or quite sheathless; perigynia not golden-yellow nor pulverulent 

at maturity (37) 

36(35). Mature perigynia whitish-pulverulent, elliptic-obovoid, not fleshy nor 
translucent, rather obscurely ribbed; scales appressed..31. C. Hassei. 

36. Mature perigynia golden-orange to rich dark-brown, orbicular-obovoid, fleshy, 

translucent, coarsely ribbed; scales spreading 32. C. aurea. 

37(35). Scales aristate, subulate-tipped; equaling or longer than the perigynia 

33. C. crinita. 

37. Scales obtuse to acute, not aristate (38) 

38(37). Flowering culms from the center of a tuft of leaves of the previous year 
(39) 

38. Flowering culms all or mostly arising laterally, not from the center of a tuft 

of leaves from the previous year (42) 

39(38). Leaf sheaths breaking and becoming filamentose 34. C. senta. 

39. Leaf sheaths not becoming filamentose when breaking (40) 

40(39) . Perigynia conspicuously veined or ribbed ventrally (41 ) 

40. Perigynia nerveless ventrally or with obscure impressed nerves; scales 

appressed 35. C. aquatilis. 

41(40). Perigynia early-deciduous, membranaceous, conspicuously stipitate, the 

apiculate beak entire; lowest bract exceeding the inflorescence 

36. C. Kelloggii. 

41. Perigynia persistent, coriaceous, strongly ribbed, the broad beak bidentate; 

lowest bract equaling the inflorescence 37. C. nebraskensis. 

42(38). Lower sheaths fibrillose; juncture of sheath and blade V-shape 

38. C. stricta. 

42. Lower sheaths not fibrillose; juncture of sheath and blade flat or slightly 

arcuate 39. C. Emoryi. 

43 ( 1 ) . Lower part of style hard, texturally similar to the achene, persistent (44) 

43. Lower part of style jointed to achene, texturally difi'erent, withering and be- 

coming detached from mature achene (59) 

44(43). Perigynia obconic or broadly obovoid, truncate or abruptly rounded to 
a long subulate beak (45) 

44. Perigynia subulate to ovoid or subglobose, gradually tapering to a beak (48) 

45(44). Spikes elongate, linear-cylindric; achene silvery-black, minutely pitted.... 
40. C. ultra. 

45. Spikes subglobose to thick-cylindric or ellipsoid; achene yellow to brown, 

granular (46) 

46(45). Terminal spike staminate; pistillate rough-awned scales longer than the 
perigynia 41. C. Frankii. 

46. Terminal spike gynecandrous; pistillate scales shorter than the bodies of the 

perigynia (47) 

47(46). Pistillate scales obtuse; style straight 42. C. typhina. 

47. Pistillate scales acuminate or awned; style curved 43. C. squarrosa. 

493 



48(44). Perigynia firm, tough-membranous, only slightly acuminate 

44. C. hyalinolepis. 

48. Pergynia thin or papery, acuminate (49) 

49(48). Perigynia finely and closely ribbed; pistillate scales with scabrous awns 
equal to or longer than the body of the scales (50) 

49. Perigynia coarsely ribbed; pistillate scales blunt to cuspidate or short-awned 

(53) 

50(49). Perigynia closely investing base of achenes, not inflated, greenish, be- 
coming pale-brown, the teeth arched-divergent; leaves strongly sep- 
tate-nodose; ligules prolonged 45. C. comosa. 

50. Perigynia loosely investing achenes, inflated, straw color or yellow-green; 

leaves less conspicuously septate-nodose; ligules about as broad as 
long (51) 

51(50). Perigynia 2.5-4 mm. thick, about 10-nerved 48. C. lurida. 

51. Perigynia less than 2 mm. thick, with 12 to 20 nerves (52) 

52(51). Perigynia 5-7 mm. long, inflated, the beak about 2 mm. long; body of 
pistillate scales small 46. C. hystericina. 

SI. Perigynia 4-5 mm. long, slightly inflated, the beak 1.5 mm. long; body of 
pistillate scales large 47. C. Thurberi. 

53(49). Perigynia 8-20 mm. long (54) 

53. Perigynia 3.5-8 mm. long (58) 

54(53). Perigynia subulate to slenderly lanceolate, 1-3 mm. thick, delicately 
nerved, barely inflated 51. C. folliculata. 

54. Perigynia lanceolate to ovoid or flask-shaped, 3-8 mm. thick, strongly 

nerved, usually much inflated (55) 

55(54). Plants densely cespitose, without elongate stolons; pistillate spikes glo- 
bose or nearly so; style straight or slightly bent (56) 

55. Plants stout and leafy, with creeping stolons; pistillate spikes thick-cylindric 

or ellipsoid; style spirally bent (57) 

56(55). Perigynia cuneate at base, firm, opaque, dull-green, often hispidulous 
52. C. Grayi. 

56. Perigynia rounded at base, membranous, lustrous, glabrous 

53. C. intumescens. 

57(55). Achene longer than wide, the angles prominent but not really knobby 
54. C. hipidina. 

57. Achene wider than long, the angle definitely knobby 55. C. gigantea. 

58(53). Rhizomes without horizontal stolons; culms slender, rarely spongy-based; 
leaves not conspicuously septate-nodulose; ligule longer than wide 
49. C. vesicario. 

58. Rhizomes with long horizontal stolons; culms mostly thick and spongy at 

base; leaves prominently septate-nodulose; ligule as wide as long.... 
50. C. rostrata. 

59(43). Spike solitary per culm 56. C. leptalea. 

59. Spikes 2 to numerous per culm (60) 

60(59). Achenes only obscurely 3-angled, with rounded or convex sides, slightly 
pubescent, closely filling the bodies of the perigynia (61) 

60. Achenes definitely 3-anglcd, with flat or concave sides (62) 

61(60). Most of the culms short and hidden among the leaves; perigynia 3-4 
mm. long 57. C nifyromarginata. 

61. Most of the culms not hidden among the leaves; perigynia 2.5-3 mm. long 

58. C. physorhyncha. 

494 



62(60). Perigynia tightly filled to tip by achenes; base of style bulbous-thickened 
59. C. eburnea. 

62. Perigynia not tightly filled by achenes, at least the summit usually empty 

(except for the style) (63) 

63(62). Bract at base of inflorescence (excluding rare basal spikes) sheathless 
or barely sheathing (64) 

63. Bract at base of inflorescence with a prolonged closed and tubular sheath 

(76) 

64(63). Leaves and perigynia glabrous (65) 

64. Leaves (or sheaths) or perigynia or both pubescent (73) 

65(64). Perigynia compressed (C. serratodens may be plump), 1-2 mm. thick, 
strongly appressed-ascending (at least before maturity) (66) 

65. Perigynia plump, 1.7-3.5 mm. thick, spreading to spreading-ascending (71) 

66(65). Pistillate scales small, acute to obtuse, 1.5-2.5 mm. long, persistent, 
purplish-black; perigynia 2-2.5 (-3.5) mm. long 60. C. media. 

66. Pistillate scales larger or sharp-pointed or both; perigynia 3 mm. long or 

more (67) 

67(66). Terminal spike staminate 61. C. serratodens. 

67. Terminal spike gynecandrous, the terminal flowers pistillate (68) 

68(67). Perigynia densely papillose, glaucous-green, trigonous-biconvex; pistillate 

scales usually aristate, their tips exceeding the perigynia 

62. C. Buxbaumii. 

68. Perigynia puncticulate or granular but not papillose; pistillate scales not 

aristate (69) 

69(68). Perigynia not granular-roughened, the margins smooth; lower spikes on 
long slender peduncles 63. C. bella. 

69. Perigynia granular-roughed, especially on the upper margins; spikes sessile 

or short-peduncled (70) 

70(69). Lowest spike slightly separate, short-peduncled; scales rough-papillose, 
with very conspicuous white-hyaline apex and upper margins; apex 
of perigynium body obtuse 64. C. albonigra. 

70. All spikes densely aggregated, sessile; scales with very inconspicuous hyaline 

margins; apex of perigynium body acute 65. C. nova. 

71(65). Terminal spike pistillate except at base; perigynia as broad as long, 
transversely rugose 66. C. Shortiana. 

71. Terminal spike staminate; perigynia not transversely rugose (72) 

72(71). Pistillate scales gradually tapering or rounded to the awn; perigynia 4-5 
mm. long, strongly ribbed 67. C. Joorii. 

72. Pistillate scales refuse and notched below the awn; perigynia 2.8-3.5 mm. 

long, essentially nerveless 68. C. glaucescens. 

73(64). Leaves septate-nodulose; perigynia densely soft-hairy 

69. C lanuginosa. 

73. Leaves or sheaths pubescent; perigynia not pubescent (74) 

74(73). Spikes usually 2 per culm, the lower ones 7-10 mm. thick; scales of 
the lower part of the ovoid pistillate portion of the terminal spike 
strongly cuspidate, 4-5 mm. long, longer than the perigynia; 
perigynia 3-5 mm. long 70. C. Bushii. 

lA. Spikes usually 3 (sometimes 4) per culm, the lower ones 4—6 mm. thick; 
scales of lower part of the ovoid-cylindric to cylindric pistillate 
portion of the terminal spike 1.5-3 mm. long, shorter than or 
equaling the mature perigynia; perigynia 1.8-2.8 mm. long (75) 

495 



75(74). Perigynia in transection flattened-triangular to unequally biconvex, 
2.3-2.8 mm. long, ascending 71. C. complanata. 

15. Perigynia in transection nearly round, 1.8-2.3 mm. long, spreading 

72. C caroliniana. 

76(63). Perigynia ascending or not strongly divergent; the orifice entire, oblique 
or but slightly notched (77) 

76. Perigynia usually soon divergent, many-ribbed, 2-3 mm. long, the beak one- 
third as long as the body; beak minutely bidentate 

73. C. viridula. 

71(76). Terminal spike regularly pistillate except at base 74. C. oxylepis. 

11 . Terminal spike regularly staminate throughout (78) 

IS(ll). Culms from lateral buds or sometimes central, relatively weak, readily 
compressed, soon shriveling after maturity of fruit; perigynia ellip- 

soid-obovoid, 3-4.5 mm. long, strongly asymmetrical 

75. C. hianda. 

78. Culms from centers of leafy tufts, slender and firm, not easily compressed, 

long-persistent after falling of fruit (79) 

79(78). Pistillate spikes linear- to oblong-cylindric, the lower peduncled and 
usually drooping or loosely spreading; perigynia lanceolate to fusi- 
form or ovoid (80) 

79. Pistillate spikes oblong-cylindric, erect or ascending, only rarely with elon- 

gated peduncles; perigynia ellipsoid to oblong-ovoid or subglobose 
(81) 

80(79). Bases purple or purplish; lowest sheaths at base of culm without green 

blades; perigynia fusiform-lanceolate, 4-10 mm. long 

76. C. dehiUs. 

80. Bases drab or brown; lowest sheaths at base of culms with elongate green 

blades; perigynia lance-ovoid, subfusiform, 2-3 mm. long 

77. C. cupilloris. 

81 (79) . Perigynia with elevated ribs, 2-3.6 mm. long (82) 

81. Perigynia with impressed nerves, 4-6 mm. long (84) 

82(81). Plant cespitose with several culms from a crown; leaves flat, flaccid; 
staminate spikes sessile or short-peduncled 78. C. granulans. 

82. Plant loosely stolonifcrous with culms solitary; leaves often folded, firm; 

staminate spike long-peduncled (83) 

83(82). Pistillate spikes 4-6 mm. thick; perigynia 3-3.5 mm. long, many-nerved, 
with minute hyaline-tipped beak 79. C. Crawei. 

83. Pistillate spikes 7.5 mm. thick; perigynia 3-4.5 mm. long, definitely ribbed, 

the beak strongly bidentate 80. C. microdonta. 

84(81). Leaves thin and flaccid to firm, green, rarely glaucous, 1.5-4 mm. 
wide; lower spike 8-13 (-20) mm. long, with 3 to 6 (to 10) 
perigynia 81. C. amphihola. 

84. Leaves firm to coriaceous, usually glaucous, 4-10 mm. wide; lower spike 

12-50 mm. long, with 8 to 32 perigynia 82. C. ffaccospcrnia. 

1. Carex Doiiglasii Boott. Fig. 255. 

Rhizomes 1-2 mm. thick, tough; culms 6-30 cm. tall, slender but stiff, obtusely 
triangular, smooth, usually overtopping the leaves but sometimes shorter; leaves 
clustered near the base, 5-15 cm. long, 1-2.5 mm. wide, involute above and flat 
or channeled toward base; heads usually dioecious, the many spikes closely aggre- 
gated but usually distinguishable; pistillate heads suborbicular to oblong. 1.5-5 
cm. long, 1-2.5 cm. thick; scales yellowish-brown with broad hyaline margins and 

496 




Fig. 255: Carex Douglasii: a, habit, staminate plant, X %: b, habit, pistillate plant, 
X %; c, staminate flower with subtending scale, X 8; d, scale of pistillate flower, X 8, e, 
perigynium, strongly nerved, abaxial view, X 8; f, pistillate flower with perigynium 
removed, X 8; g, achene (cross section), X 8; h, perigynium, lightly nerved, adaxial 
view, X 8; i, ligule, truncate with ciliate margin, X 8. (From Mason, Fig. 96). 




Fig. 256: Carex simufata: a. perigyniiim, abaxial view, X 12; b, perigynium, adaxial 
view, X 12; c, achene (cross section), X 12; d, pistillate flower with perigynium re- 
moved, X 12; e, scale of staminatc flower, X 12; f, scale of pistillate flower, X 12; g, 
hahit, showing bractless pistillate heads, X -,-,; h, ligule (on adaxial side of blade), 
X 8, i, ligular region of leaf, abaxial view, X 8; j, pistillate inflorescence, showing sub- 
tending bracts, X 4. (From Mason, Fig. 97). 



green center, acuminate to cuspidate, concealing perigynia; staminate heads similar 
but somewhat narrower; lowest bract short-cuspidate, not extending beyond tip of 
inflorescence; perigynia appressed-ascending, ovate-lanceolate, 3-4.5 mm. long, 
1.7 mm. wide, straw-colored to brownish, plano-convex, coriaceous, lightly nerved 
ventrally, strongly nerved dorsally, rounded and short-stipitate at base, sharp- 
edged, serrulate above middle, the beak obliquely cut dorsally, in age minutely 
bidentate, the apex hyaline; achenes lenticular, obovate, brown, shiny, about 1.7 
mm. long, 1.2 mm. wide; style and 2 stigmas conspicuous at flowering time. 

Wet meadows, in wet mud and on seepage banks or dryish alkaline flats, in 
N.M. (Taos Co.) and Ariz. (Coconino, Mohave and Cochise cos.); Can. to N.M., 
Ariz, and Calif. 

2. Carex simulata Mack. Short-beaked sedge. Fig. 256. 

Culms 2.5-5.5 dm. tall, sharply triangular and roughened on the angles above, 
overtopping the leaves; leaf blades 2-4 mm. wide, flat or channeled, light-green; 
spikes densely aggregated into a linear-oblong or oblong-ovoid head 12-25 mm. 
long and 5-10 mm. thick, wholly pistillate, wholly staminate or pistillate and partly 
staminate above, the lower spikes distinguishable; bracts absent or if present then 
shorter than head, cuspidate and enlarged at base; pistillate scales concealing 
perigynia, cuspidate or short-awned, brown with narrow hyaline margin and prom- 
inent lighter midvein; perigynia ascending, unequally biconvex to plano-convex, 
broadly ovate, smooth, shining, coriaceous, yellowish brown to chestnut-colored, 
1.75-2.25 mm. long, 1.5 mm. wide, rounded and short-stipitate at base, sharp- 
edged, nerveless ventrally. slenderly few-nerved dorsally, the upper part of the 
body and beak serrulate (sometimes only sparingly so), the beak obliquely cut 
dorsally, its apex at length minutely bidentate and slightly hyaline; achenes 
lenticular, obovoid, yellowish-brown, 1 mm. long. 

Wet meadows, streams, swales, or marshes, in N.M. (Grant and Sandoval cos.) 
and Ariz. (Apache and Santa Cruz cos.); Mont, to Wash., s. to N.M., Ariz, and 
Calif. 

3. Carex praegracilis W. Boott. Clustered field sedge. Fig. 257. 

Perennial; rhizomes 2-4 mm. thick, blackish, fibrous, creeping (but with inter- 
nodes only 1 mm. long); culms rising at close intervals, 12-30 cm. long, 1-3 mm. 
thick, leafy; blades mostly folded, long-tapered to a fine point, the uppermost ones 
usually slightly exceeding the inflorescence; inflorescence 15-45 mm. long, 6-10 
mm. thick, of about 6 to 15 short glomeriform androgynous spikes, the lower 1 
or 2 spikes usually weakly separated from the rest; scales hyaline marginally, 
acuminate, longer than the perigynia; perigynia (about 10 per spike) plano-convex, 
ascending, thin-coriaceous and brownish black when mature and with sharp 
coriaceous margins, the body obovate or ovate, 3-4 mm. long, 1.5-2 mm. broad, 
tapering into a serrulate beak half the length of the body or more; achene lentic- 
ular, about 1.3 mm. long, 1 mm. wide. 

In wet meadows and water of streams and lakes, infrequent in moist canyons 
of basaltic mts. at elev. of 4,000-8,000 ft. in the Tex. Trans-Pecos (Chisos and 
Davis mts.), N.M. (Grant and Sandoval cos.) and Ariz. (Apache to Mohave, s. 
to Cochise and Pima cos.), spring-early summer; temp. w. N.A., in mts. s. to 
Mexico City. 

4. Carex disperma Dewey. 

Loosely tufted from long slender rhizomes; culms very slender and weak, 6-60 
cm. high, mostly exceeding the leaves, usually nodding; leaves thin, soft and flat, 
0.75-2 mm. wide; sheaths tight, very thin and hyaline ventrally; spikes 2 to 4, 
androgynous, the lower separate, the upper aggregated, with 1 to 3 (or the ter- 
minal with 3 to 6) perigynia and 1 or 2 apical inconspicuous staminate flowers; 

499 



'WV'/ 



x^^/ ^1 




Fig. 257: Carcx praef-racilis: a, scale of upper pistillate flower, X 10; b, pistillate 
flower with perigynium removed, X 10; c, perigynium, lightly several-nerved, beak 
obliquely cut, abaxial view, X 10; d, perigynium, adaxial view, X 10; e. lower pistillate 
spikes with short subtending bracts, X 4; f, achene (cross section), X 10; g, habit, 
showing the erect-ascending leaf blades, X r-,; h. habit, showing the dark basal sheaths 
and the culms extending above the leaves, X ^f,; i, ligule, X 10. (From Mason, Fig. 98). 




Fig. 258: a-d, Carcx cephalophora: a, inflorescence, X IV^', b, pistillate scale, X 15; 
c, perigynium, dorsal view, X 15; d, perigynium, ventral view, X 15. e-h, Carex fissa: 
e, inflorescence, X 1; f, pistillate scale, X 10; g, perigynium, dorsal view, X 10; h, 
perigynium. ventral view, X 10. i-1, Carex vidpinoidea: i, inflorescence, X 1; j, pistil- 
late scale, X 12; k, perigynium, dorsal view, X 12; 1, perigynium, ventral view, X 12. 
m-p, Carex retroflexa: (woodland species), q-t, Carex Muhlenbergia: (woodland 
species). (Courtesy of R. K. Godfrey). 



scales ovate-triangular, white-hyaline with green midrib, narrower and shorter 
than the perigynia; perigynia plump, unequally biconvex, elliptic-ovoid, 2-2.8 
mm. long, 1.5 mm. wide, light-green to yellow-green, finely many-nerved on both 
surfaces, white-punctate, short-stipitate, abruptly contracted into a minute entire 
beak; achenes lenticular, oblong-elliptic, brownish-yellow, glossy, 1.7 mm. long, 

1 mm. wide. 

In boggy meadows, coniferous woods, and on peaty banks of streams and 
lakes, in N. M. (Sandoval, San Miguel, Santa Fe and Taos cos.); Lab. to Alas., 
southw. to N.J., Ind., N.M., Ariz, and Calif.; also Euras. 

5. Carex canescens L. 

Plants densely cespitose from short rootstocks. often in large tussocks; culms 
1-8 dm. high, soft, sharply triangular, often lax and widely spreading; leaves 
glaucous-green, soft, flat, 2-4 mm. wide; sheaths tight, thin and hyaline ventrally; 
spikes 4 to 8, silvery-brown, the upper approximate, the lower separate, containing 
10 to 30 appressed-ascending perigynia, the terminal generally clavate at the 
staminate base; scales broadly ovate, hyaline with a green center, shorter than 
the perigynia; perigynia plano-convex, ovoid-oblong, 1.8-3 mm. long, 1.25-1.75 
mm. wide, pale-green to whitish-brown, more or less nerved on both surfaces, the 
sharp margin smooth throughout or only minutely serrulate at the base of the 
very short inconspicuous or obsolete beak; achenes lenticular, oblong-obovate, 
substipitate, 1.5 mm. long, 0.9 mm. wide. 

Locally abundant on lake margins and shallow water, and in swamps and bogs, 
in N.M. (Taos Co.) and Ariz. (Apache Co.); Nfld. to Alas., s. to N.J., N.M., 
Ariz, and Calif.; also Euras. and Austral. 

6. Carex cephalophora Muhl. Fig. 258. 

(Sub-) rhizomatous perennial; rhizomes 2-10 cm. long, much-branched, about 

2 mm. thick, with very short internodes; culms 15-30 (-45) cm. long, 1-2 mm. 
thick, ascending; leaves 2 to 4 per culm, mostly basal; blades about 15 cm. long 
and 2 mm. broad, the sheaths ventrally smooth, rather tight-fitting, stramineous, 
the orifice broadly U-shaped; spikes 5 to 10. each with about 10 perigynia. very 
short, sessile, androgynous, aggregated in a narrow more or less ovoid nearly or 
usually quite bractless head 10-15 (-17) mm. long and 4-9 mm. broad; scales 
inconspicuous, shorter than the perigynia; perigynia ascending, much-flattened, 
broadly ovate, the body 1.5-2.5 mm. long and 1-1.5 mm. broad, plano-convex, 
ventrally quite smooth and with raised margins, basally not differentiated or else 
discoloring brown in the basal third to fourth the length, firm-membranous, with 
inconspicuous only slightly tougher margins and with a very short triangular beak 
less than half as long as the body; achene lenticular, about 1.7 mm. long, 1.5 mm. 
wide. Incl. var. angustifoUa Boott and some plants referred to C "inesochorea" 
Mack., C. Leavenworthii Dew. 

Frequent in usually moist sandy soil at base of bluffs, in wettish pasturelands, 
in Okla. (Cherokee and Muskogee cos.) and in e., s.e. and n.-cen. Tex., rare in 
parts of Edwards Plateau (Enchanted Rock), spring; e. N.A., w. to Mich.. Lt., 
Mo., Okla. and Tex. 

7. Carex decomposita Muhl. Fig. 259. 

Perennial, the branching fibrous blackish rhizomes with internodes several mm. 
to several cm. long; culms weakly arcuately ascending, soft, 5-15 dm. long. 3-7 
mm. thick, nearly terete; lower sheaths brownish or reddish-brown. 1-2 cm. long; 
sheath venters papery, tending to split at maturity, not at all wrinkled, orifice 
weakly rounded; upper leaves long, much-surpassing the inflorescence; inflores- 
cence a decompound panicle of 5 to 10 spiciform erect branches (the lower 
branches longer than the upper ones), each branch bearing 5 to 20 short ovoid 

502 




Fig. 259: a-d, Carex decomposita: a, inflorescence, X Vo', b, scale, X 12; c, peri- 
gynium, dorsal view, X 12; d, perigynium, ventral view, X 12. e-g, Carex crus-corvi: 
e, inflorescence, X V-r, f, scale, X 10; g, perigynium, X 10. h-k, Carex laevivaginata: 
h, habit, X 1/2; i, scale, X 7; j, perigynium, dorsal view, X 7; perigynium, ventral view, 
X 7. (Courtesy of R. K. Godfrey). 



sessile androgynous brownish essentially bractless spikes each with 8 to 13 peri- 
gynia; scales narrower and shorter than the perigynia; perigynia bodies obovate 
or obpyramidal, plano-convex, firm, 1.5-2.5 mm. long, nearly as broad, sharp- 
edged laterally; beak abrupt, 0.3-0.5 mm. long, bidentate; achene lenticular, very 
closely enveloped, about 1 mm. long and wide. 

Rare in wet areas, usually on rotten logs at lake-margins, n.e. Tex. (Marion 
and Wood cos.), spring; e. U.S. n. to N.Y. and Mich., w. to Mo. and Tex. 

8. Carex vulpinoidea Michx. Fig. 258. 

Densely matted rhizomatous perennial; rhizomes 2-4 mm. thick, dark-brown 
or black, fibrous, internodes only 1-2 mm. long; culms 35-70 (-90) cm. long, 
1.5-3.5 mm. thick, erect; sheaths tight, ventrally papery, strongly and closely 
transversely wrinkled, at the orifice firm and rounded; leaf blades diverse, the lower 
ones only 5-10 cm. long, the upper very long and equaling or surpassing the 
heads, tapered to a setaceous tip; inflorescence interrupted-spiciform, 35-80 mm. 
long, 7-13 mm. thick, of 10 to 15 short sessile androgynous spikes (each with 15 
to 30 perigynia), all except the lowermost bractless (in var. platycarpa Hall) or 
with setaceous bracts 10-30 (-80) mm. long (in var. vulpinoidea): scales papery, 
lanceolate, acute, about equaling or usually a little shorter than their perigynia; 
perigynial bodies ovate to suborbicular, 2.5-3 mm. long, 2-3 mm. broad, strongly 
compressed, mostly flat ventrally, very slightly convex dorsally, smooth or usually 
serrulate marginally, ventrally usually with a few veins and often on both faces 
at maturity becoming brownish and firm-membranous; beak of perigynium either 
abruptly difi'erentiated from and only about a third as long as the body (var. 
platycarpa) or less abrupt and about half as long as the body (var. vulpinoidea), 
bidentate. serrulate or entire-margined; achene lenticular, about 1.3 mm. long, 
1 mm. wide. C. triangularis Boeck., C. annectans Bickn. 

In low wet woods and swamps in wet mud on edge of lakes, ponds and streams; 
the var. platycarpa Hall is frequent in Okla. (Johnston, Alfalfa. McCurtain, Adair, 
Caddo, Haskell and Atoka cos.) and in e. and s.e. Tex., rare in n.-cen. Tex. 
(Denton Co.); var. vulpinoidea is rare in the Tex. Plains Country (Dallam and 
Hemphill cos.), N.M. (San Miguel Co.) and Ariz. (Apache and Cochise cos.), 
spring (var. platycarpa) or summer (var. vulpinoidea); e. temp. N.A. w. to the 
Rocky Mts.; also B.C., Wash, and Ore. 

9. Carex alma Bailey. 

Cespitose from short-prolonged stout rootstocks; culms aphyllopodic, 3-12 dm. 
high, roughened above, exceeding the leaves; leaves clustered toward the base, 
thickish, flat or channeled, 3-6 mm. wide, the margins strongly serrulate; sheaths 
tight, somewhat septate-nodulose dorsally, thin and purplish-dotted ventrally, the 
ligule about as wide as long; spikes densely aggregated into an oblong head 3-12 
cm. long, the lower sometimes separate, the individual spikes seldom distinguish- 
able, the perigynia appressed; scales ovate, about the size of the perigynia. straw- 
colored or brownish with white-hyaline margins, the midrib prominent, awned to 
acute; perigynia plano-convex, ovate to oblong-ovate, 3.5-4 mm. long, 1.6-1.8 
mm. wide, almost black at maturity, obscurely nerved on both surfaces, round- 
truncate at the base, substipitate, narrowly sharp-margined and serrulate above, 
more or less abruptly contracted into a serrulate bidentate beak about one-third 
the length of the body, the triangular teeth very short; achenes lenticular, ovoid, 
1.5 mm. long, substipitate. 

In wet soil along streams, in Ariz. (Gila, Maricopa and Cochise cos.); also 
Nev. and Calif. 

504 




Fig. 260: Carex stipata: a, perigynium, abaxial view, showing the strong nerves 
and the round-cordate spongy base, X 10; b, achene (cross section), X 10; c, peri- 
gynium, adaxial view, the nerves less developed than on abaxial side, X 10; d, achene, 
showing the spongy base of the perigynium, X 10; e, pistillate flower with perigynium 
removed, showing the stipitate achene, the short style and 2 long stigmas, X 10; f-h, 
scales of pistillate flowers, showing variation in shape of scale and in length of awn, 
X 10; i, ligule, X 4; j, inflorescence, the spilces not crowded, the bracts bristlelike, 
X %; k, staminate flower and subtending scale (lowermost flower in spike), X 10; 1, 
habit, showing the conspicuous leaf sheaths and flat flaccid blades, X %. (From Mason, 
Fig. 104). 



10. Carex fissa Mack. Fig. 258. 

Cespitose; rootstock short, stout, black, fibrillose; culms 2.5-7.5 dm. long, 4-7 
mm. wide at base, bluntly triangular, smooth or roughened beneath head, light- 
brown at base; well developed leaves 4 to 6 to a culm, on lower third; blades 1-2 
dm. long, 3-5 mm. wide, flat or channeled, thick, light-green; sheaths thin and 
cross-rugulose ventrally, prolonged, red-dotted near mouth; ligule wider than long; 
spikes 10 to 20, androgynous, in a head 2.5-4 cm. long and 8-18 mm. wide; lower 
bracts setaceous, the upper scalelike; scales acute or cuspidate, hyaline, light- 
yellowish-brown-tinged with green midvein; staminate flowers inconspicuous; peri- 
gynia 8 to 20 in a spike, 3.5 mm. long and 2 mm. wide, ascending or spreading, 
piano- or concavo-convex, submembranous. light-green or yellowish-brown-tinged, 
few-nerved dorsally, sharp-margined, serrulate above, substipitate; beak 1 mm. 
long, serrulate, dorsally cleft, bidentate, light-reddish-brown-tinged; achenes 2 mm. 
long, 1.7 mm. wide, lenticular, substipitate, apiculate, jointed with the short style 
which is enlarged at base; stigmas 2, reddish-brown. 

On wet ditch banks in Okla. ( Waterfall) . 

11. Carex crus-corvi Kunze. Fig. 259. 

Densely tufted perennial (the internodes of the rhizomes very short); culms 
4-9 dm. long, 4-12 mm. thick basally, soft; sheaths soft, ventrally thin-papery 
and easily splitting, the orifice horizontal or shallowly U-shaped, not thickened; 
blades long, often surpassing the inflorescence; inflorescence a decompound pan- 
icle 6-15 (-19) cm. long and 15-40 mm. thick, with 7 to 13 ascending or erect 
short branches (the lower-middle branches the longest), each branch with 3 to 
10 burlike sessile androgynous bractless spikes each with only a few perigynia; 
scales lanceolate, about as long as or slightly exceeding the body; perigynial body 
triangular, largely plano-convex, 2-3 mm. long, firm, brownish, basally inflated, 
discolored whitish, truncately narrowed to the minute stipelike base, apically 
passing into the linear strongly bidentate beak (3-4 mm. long); achene lenticular, 
up to 2 mm. long, 1 .3 mm. wide. 

In mud on edge of lakes, ponds and streams, and in shallow water, in Okla. 
(McCurtain, Choctaw and Love cos.), frequent in e. Tex., infrequent in s.e. and 
n.-cen. Tex., rare in the Plains Country (Wichita Co.), spring; Gulf States and 
n. in cen. U.S. to O., Mich., Minn, and Wise. 

12. Carex stipata Muhl. Fig. 260. 

Densely tufted perennial, the internodes of the rootstocks very short; culms 
3-10 dm. long, 3-7 (-12) mm. thick basally, rather soft, triangular above with 
concave sides; sheaths soft, ventrally not transversely wrinkled, easily splitting, 
orifice horizontal or slightly prolonged and rounded, not thickened; upper blades 
usually about equaling the inflorescence; inflorescence a dense decompound pan- 
icle 3-10 cm. long and 10-25 mm. thick, with several ascending branches (the 
lower branches longer), each branch with 2 to 10 sessile subglobose essentially 
bractless androgynous spikes each with 8 to 15 perigynia; scales ovate, acuminate, 
about equaling the perigynia; perigynia 4-6 mm. long, the bodies plano-convex, 
ovate, firm, 2-3 mm. long, basally more or less discolored brownish-stramineous, 
firmer, abruptly narrowed to a minute stipe, apically passing into the linear beak 
which is strongly bidentate and 2-3 mm. long; achene lenticular, about 1.7 mm. 
long, 1.5 mm. wide. Incl. var. maxima Chapm., C. uberior (Mohr) Mack. 

In mud on edge of streams and ponds, wet meadows and marshes, in Okla. 
(McCurtain Co.), rare in e. Tex. (Austin and Leon cos.), N.M. (Catron, San 
Miguel, Colfax and Sandoval cos.) and Ariz. (Apache, Navajo, Coconino, Graham 
and Gila cos.), spring; most of temp. N.A. (except extreme s.w. U.S. and Mex.). 

506 



13. Carex laevivaginata (Kiikenth.) Mack. Fig. 259. 

Closely resembling C. stipata in general habit and size; sheaths not cross-puck- 
ered, at the mouth distinctly concave and thickened, hence not easily torn and 
well-preserved in most herbarium material; spike shorter and less compound, 2-5 
cm. long. 10-15 mm. thick, green or tinged with straw-color at maturity; scales 
acuminate, shorter than the perigynia; perigynia lance-ovoid, plano-convex, 4.9-6.2 
mm. long, averaging 5.2 mm. and usually less than a third as wide; achene lentic- 
ular, stipitate, ovate, 2 mm. long (including stipe), 1.3 mm. wide. 

Boggy or swampy woods and meadows, in Okla. {Waterfall) \ Mass. to Mich, 
and Minn., s. to n. Fla. cen. Ga., Tenn., Okla. and Mo. 

14. Carex leptopoda Mack. 

Loosely cespitose from slender elongate rootstocks; culms slender, 2-8 dm. 
high, sharply triangular and roughened below the head, exceeding the leaves; 
leaves yellowish-green to light-green, flat or the margins somewhat revolute, 2-5 
mm. wide; sheaths rather loose, hyaline ventrally, the ligule acuminate and pro- 
longed; spikes 4 to 7, ovoid or oblong, aggregated into a loose head 2-4 cm. long, 
but the lower 1 to 3 usually separate, the lateral pistillate, the terminal gynecan- 
drous; scales oblong-ovate, obtuse to acute or cuspidate, about the length of the 
perigynium bodies, greenish-white with green center; perigynia plano-convex, 
ovate-lanceolate, 3.5-4 mm. long, 1.5 mm. wide, greenish to greenish-white, 
several-nerved toward the base dorsally, nerveless to very few- and short-nerved 
ventrally, contracted into a serrulate bidentate beak half the length of the body; 
achenes lenticular, suborbicular, about 1.5 mm. long and 1.25 mm. wide, 
yellowish-brown. 

On moist or wet soil of wooded slopes and flats, and in low swampy places, 
from near sea level to 10,000 ft., in Ariz. (Apache, Coconino and Pima cos.); 
Mont, to B.C., s. to Ariz, and Calif. 

15. Carex Bolanderi Olney. 

Cespitose from slender short-prolonged rootstocks; culms slender, 1.5-9 dm. 
high, sharply triangular, smooth or somewhat roughened below the head, exceed- 
ing the leaves; leaves yellowish-green to pale-green, flat, 2-5 mm. wide; sheaths 
rather loose, hyaline ventrally, the acuminate ligule much longer than wide; 
spikes 5 to 8, linear-oblong, the lower 1 to 5 more or less separate, the rest 
aggregated into a head 3-8 cm. long, gynecandrous but the staminate flowers 
inconspicuous; scales ovate to lanceolate-ovate, acute to short-awned, brownish 
with green center, exceeding the perigynium bodies; perigynia plano-convex, 
lanceolate, 4-4.5 mm. long, 1-1.25 mm. wide, yellowish-green, strongly several- 
nerved dorsally, lightly several-nerved (at least at the base) ventrally, tapering 
somewhat abruptly into a serrulate deeply bidentate beak more than half the 
length of the body; achenes lenticular, suborbicular or obovate, about 1.75 mm. 
long and 1.25 mm. wide, yellowish-brown. 

Along streams, in wet meadows and on edge of marshes, from sea level to 
8,500 ft., in N.M. (Mora Co.) and Ariz. (Coconino, Pinal, Cochise, Santa Cruz 
and Pima cos.) ; Mont, to B.C., s. to N.M., Ariz, and s. Calif. 

16. Carex interior Bailey. 

Densely cespitose from short dark-colored rootstocks; culms erect or ascend- 
ing, slender but firm, wiry and strict, sharply triangular, 1.5-5 dm. high, usually 
longer than the leaves; leaves about 3 to a culm, thin, flat or slightly channeled, 
1-3 mm. wide; sheaths tight, the ligule wider than long; spikes 2 to 4 (6), some- 
what but not closely crowded into an oblong head, the terminal usually 
gynecandrous and long-clavate but sometimes entirely staminate and narrowly 

507 



linear or almost entirely pistillate and oblong, the 1 to 10 perigynia of the lateral 
spikes widely spreading at maturity; scales broadly ovate, very obtuse, yellowish- 
brown with broad white-hyaline margins and green center, half the length of 
the bodies of the perigynia; perigynia concavo-convex, oblong-ovoid to deltoid, 
2.25-3.25 mm. long, 1.5-2 mm. wide, plump and firm, the body broadest just 
above the base, thick-margined, olive-green becoming brown, several-nerved 
dorsally, nerveless to definitely nerved ventrally, rather abruptly narrowed into 
a sparingly serrulate shallowly bidentate beak about one-third or one-fourth the 
length of the body, the ventral false suture inconspicuous; achenes lenticular, 
broadly ovate-orbicular, 1.3 mm. long and about as wide just below the middle. 
In swampy meadows, calcareous bogs, and on springy banks, at moderate 
elevations (mostly 7,000-11,000 ft.) in Ariz. (Apache Co.); Lab. to B. C, s. 
to Pa., Kan., n. Calif, and cen. Mex. 

17. Carex atlantica Bailey. Fig. 261. 

Tufted perennial (internodes of the branching rhizomes less than 1 mm. long); 
culms 2-5 dm. long, about 1 (-2) mm. thick; sheaths stramineous, tight, ventrally 
papery, tending to split, the orifice horizontal or shallowly U-shaped; inflores- 
cence interrupted-spiciform, 3-5 cm. long, 5-8 mm. thick, of 3 or 4 subglobose 
bractless spikes each with 8 to 20 perigynia (rarely as many as 40) and separated 
by bare axis internodes 5-14 mm. long, the terminal spike attenuate basally (in 
the staminate portion), gynecandrous, the rest usually wholly pistillate; scales 
slightly shorter than the perigynia; perigynial bodies spreading at maturity, 1.5-1.8 
mm. long, broadly ovate to nearly orbicular, plano-convex, firm, marginally sharp 
but not winged, shiny, stramineous, with several strong nerves ventrally (use lens), 
abruptly narrowed to the beak which is linear. 0.7-0.9 mm. long and bidentate; 
achene lenticular, about 1 .7 mm. long and wide. C incomperta Bickn., C. Howei 
Mack. 

Infrequent or rare at edge of clear acid streams, edge of lakes, swamps along 
streams and seepage areas, in Okla. (McCurtain Co.) and in e. and s.e. Tex. 
(Hardin, Nacogdoches, Cass, Wood, Newton and Tyler cos.), spring; e. N.A., w. 
to Mich., Ind., Tenn. and Tex. 

18. Carex muskingumensis Schw. 

Cespitose with numerous very leafy sterile culms; fertile culms stout. 5-10 
dm. tall; principal leaf blades 3-5 mm. wide; spikes 5 to 10, fusiform, pointed 
at both ends, 15-25 mm. long, 4-6 mm. thick, closely aggregated in a dense 
cluster 4-8 cm. long; pistillate scales lanceolate, about half as long as the 
perigynia, pale-brown with hyaline margins; perigynia appressed, lanceolate, thin, 
7-10 mm. long, about a fourth as wide, finely nerved on both sides, gradually 
tapering to the beak; achene lenticular, narrowly oblong, 2-2.5 mm. long, 0.8 mm. 
wide. 

Low woods and wet meadows, swamps and alluvial floodplains, in Okla. (fide 
Fernald and Gleason); Mich., O. and Ky., w. to Kan. and Okla. 

19. Carex athrostachya Olney. Fig. 262. 

Culms cespitose, 1-8 dm. tall; leaves 2 to 4; blades flat. 1-3 mm. wide, yellow- 
ish green; head ovoid, 1-2.5 cm. long, the spikes 4 to 20. closely aggregated, 
the staminate basal flowers inconspicuous; bracts usually well developed, the 
lowest exceeding the head; scales ovate or lanceolate-ovate, shorter than perigynia, 
acute or short-cuspidate, brownish with hyaline margins; perigynia ovate-lanceo- 
late. 3-4 mm. long, light-green, becoming straw-colored or brownish, substipitate, 
ciliate-serrulate above, tapering into a slender terete brownish-tipped beak, the 
margins of the orifice hyaline; achenes lenticular, oblong-oval, about 1.5 mm. 
long and I mm. wide. 

508 




Fig. 261: a-e, Carex atlantica: a, inflorescence, X 5; b, scale, X 17; c, perigynium, 
dorsal view, X 17; d, perigynium, ventral view, X 17; e, achene, X 17. f-i, Carex 
albolutescens: f, inflorescence, X 1; g, scale, X 10; h, perigynium, dorsal view, X 10; 
i, perigynium. ventral view, X 10. j-m. Carex tribuloides: j, inflorescence. X 1; k, scale, 
X 10; 1, perigynium, dorsal view, X 10; m. perigynium, ventral view, X 10. (Courtesy 
of R. K. Godfrey). 




Fig. 262: Carex athrostachya: a, ligule. bilobed, X 8; b. lowermost spike of an 
inflorescence, showing subtending bract with aiiricled hyah'ne base and elongate, ser- 
rulate midvein and the inconspicuous staminate flowers at base of spike, X 6: c, achene 
(cross section), X 12; d, pistillate flower, showing stipitate achene, X 12; e and f, 
scales, showing variation in size and shape, X 12; g, perigynium, adaxial view. X 12; 
h, perigynium, ahaxial view, X 12; i, habit, showing the slender culms and the closely 
aggregated spikes, X '4; j, inflorescence with auricled subtending bracts, the uppermost 
much reduced, X ^r,. (From Mason, Fig. 101). 



Wet meadows and thickets, in mud on edge of ponds and lakes, and in 
seepage areas, in N. M. (Taos Co.) and Ariz. (Navajo, Coconino and Pima 
COS.); Sask. to Alas., s. to N.M., Ariz, and Calif. 

20. Carex tribuloides Wahl. Fig. 261. 

Tufted perennial; culms 3-8 dm. long, 1-2 mm. thick, basally slightly arcuate- 
ascending, mostly ascending, apically strongly angled; sheaths short, the venters 
mostly veiny except for the hyaline area near the orifice; blades (1-) 2.5-5 mm. 
broad, shorter than the culms and at least the lower ones often relatively stiff 
and diverging from the culm at an angle of 10-30° (-50°); inflorescence elongate, 
capitate or shortly subspicate. 25-50 mm. long, 9-15 mm. thick, of 5 to 15 
closely set sessile burlike obovoid to oblong ascending gynecandrous spikes 7-10 
mm. long and 3-5 mm. thick; bracts absent except occasionally a small setaceous 
one at the base of the lowest spike; scales half to two thirds as long as their 
perigynia; perigynia 50 to 80 per spike, much-flattened and scalelike, distended 
only over the achene, winged, 3.5-5.2 mm. long (including the bidentate beak 
which is about 1 mm. long), 1-1.5 mm. broad including the wings (broadest near 
the middle, i.e., in the upper half of the "body"), stramineous-brown, ventrally 
veiny, stiffly ascending and apically not appressed nor incurved; achene lenticular, 
about 1.5 mm. long, 0.7 mm. wide. 

In swampy or low wet meadows and woods of alluvial soils, in mud on edge 
of ponds, lakes and streams, in Okla. (McCurtain and Alfalfa cos.) and s.e. 
Tex. (Jefferson, Panola, Gregg, Rusk, Sabine and Montgomery cos.), May; e. 
temp. N.A. w. to Minn., Mo., Okla. and Tex. 

21. Carex microptera Mack. 

Very densely cespitose from short stout rootstocks; culms 3-10 dm. high, 2.5-4 
mm. thick at the base, conspicuously striate, sharply triangular above and 
roughened below the head, much-exceeding the leaves; leaves 3 to 5 to a culm, 
on the lower third, flat, firm, 2-6 mm. wide; sheaths tight, white-hyaline ventrally; 
spikes 5 to 20, gynecandrous, distinguishable but densely aggregated into an 
ovoid or suborbicular, truncate-based head, 12-18 (-25) mm. long, 10-18 mm. 
wide; lowest bract short-awned; scales ovate-lanceolate, acute, dull-brown, with 
faint lighter midrib, narrower and shorter than the perigynia; perigynia thin 
and flattened except where distended by the achene, lanceolate-ovate to lanceo- 
late, 3.4-5 mm. long, 1-2 mm. wide, spreading-ascending, light-green to light- 
brown, lightly several-nerved on both surfaces, very narrowly wing-margined 
to the round-tapering base, serrulate to the middle, tapering into a terete serrulate 
(smooth at the tip) bidentate beak one-third to one-half the length of the body; 
achenes lenticular, broadly obovoid, to 1.5 mm. long, about 1 mm. wide; anthers 
long-persistent, linear-oblong, spinulose apiculate, 1.3-2 mm. long. C. festivella 
Mack. 

Moist or wet places, in N.M. (Taos, Grant, San Miguel, Catron, Rio Arriba 
and Sandoval cos.) and Ariz. (Coconino, Pima and Graham cos.); B.C. to Sask. 
and Man., s. to Calif., N.M., Ariz, and in the Black Hills of S.D. 

22. Carex scoparia Schkuhr. 

Densely cespitose from short fibrillose rootstocks; culms 1.5-10 dm. high, 
usually much-exceeding the leaves, sharply triangular, the angles very rough 
below the inflorescence; leaves 2 to 6, on the lower half, flat or canaliculate, 1-3 
mm. wide, yellowish-green; spikes 3 to 12, distinct, aggregated into an oblong 
to linear-oblong or globose head (or sometimes a moniliform flexuous inflores- 
cence), gynecandrous, straw-colored, the numerous erect-ascending perigynia 
with appressed-erect beaks; scales ovate to oblong-ovate, dull, light-brownish 
with green center and narrow white-hyaline margins, nearly as wide as the 

511 



perigynia but conspicuously exceeded by the beaks; perigynia flat, thin and 
scalelike, barely distended over the achene, 4-7 mm. long. 1.2-2.6 mm. wide, 
lanceolate to narrowly ovate-lanceolate, greenish-white to straw-colored, wing- 
margined to the base, serrulate to below the middle, nerved on both faces, taper- 
ing into a flat serrulate shallowly bidentate beak 1.2-2 mm. long; achenes lenti- 
cular, oval-oblong, 1-1.5 mm. long, 0.5-0.7 mm. wide, brownish, short-stipitate. 

In open usually swampy places in seepage along streams and about ponds in 
Ariz. (Apache and Pima cos.); Nfld. to B.C., s. to S.C., Ark., N.M., Ariz, and 
Ore. 

Carex Bebbii Olney (in Colfax Co., N.M.) is similar to this species but the 
perigynia are only about 3 mm. long. 

23. Carex festucacea Schkuhr. 

Culms cespitose, slender, erect, exceeding the leaves; principal leaf blades 2-5 
mm. wide; spikes ovoid to subglobose, 6-10 mm. long, often distinctly clavate 
at base, distinct but crowded in a compact cluster or separate in an inflorescence 
3-6 cm. long; pistillate scales ovate, much shorter and narrower than the perigy- 
nia, hyaline and lightly tinged with brown, acute or acuminate; perigynia 2.7-4 
mm. long, half to three-fourths as wide, broadest at a third to half of their 
length, the body broadly ovate to obovate, finely nerved on both faces, abruptly 
narrowed to the beak; achenes lenticular, elliptic, light-brown, about 1.3 mm. 
long, 1 mm. wide. ? C. normalis Mack. 

In wooded swamps and bottomlands, in mud along streams and in swales, 
in Okla. (fide Fernald and Gleason); N.S. to N.Y., s. Mich, and la., s. to Fla. 
and Okla. 

24. Carex albolutescens Schwein. Fig. 261. 

Tufted perennial; culms 25-75 cm. long, 1-2 mm. thick, sharply triangular, 
erect; sheath venters broadly stramineous-hyaline; blades 1.5-3 mm. broad, 
shorter than the culms, in most specimens rather stiffly ascending, the lower 
ones extremely short; inflorescence interrupted-spiciform to monilifomi-spici- 
form, 25-45 mm. long, 6-10 mm. thick, of 3 to 10 sessile basally attenuate 
ovoid apically rounded ascending gynecandrous spikes 6—11 mm. long and 5-6 
mm. thick; bracts absent; scales shorter than the perigynia; perigynia 30 to 50 
per spike, 2.8-3.2 (-3.5) mm. long, 1.6-2.2 mm. broad, widest below the middle, 
the body broadly obovate, widest above the middle, at anthesis stramineous, 
very thin and distended only over the achene, winged, at maturity stramineous 
and firmer, somewhat plano-convex, ventrally nearly veinless; beak 0.6-1 mm. 
long, flat, bidentate, serrulate, at anthesis green, at maturity brownish, contrasting 
with the body; achene lenticular, about 1.3 mm. long, 1 mm. wide. 

Infrequent or rare in moist or wet sand in bogs, low wooded swamps, edge 
of water and in mud along streams and about ponds in e. (Polk, Leon and 
Sabine cos.) and s.e. (Jeff"erson Co.) Tex., Apr.; otherwise said to occur in 
Coastal States, N.S. to Fla.; also Mich., III., Ind., Mo., Tenn. and La. 

25. Carex Longii Mack. 

Tufted perennial, the rootstocks with very short internodes; culms sharply 
triangular, 3-8 dm. long, erect, 1.5-2 mm. thick; sheaths short, the venters 
mostly green and veiny except for the immediate vicinity of the orifice; blades 
1.5-4 mm. broad, shorter than the culms, at least the lower ones often relatively 
stiff and diverging slightly from the stem; inflorescence moniliform-spicate, 3-5 
cm. long, 12-15 mm. thick, of 5 to 10 sessile basally abruptly attenuate narrowly 
ovoid ascending gynecandrous spikes 7-1 I mm. long and 5-8 mm. thick; bracts 
absent except occasionally a small setaceous one at the base of the lowest spike; 
scales shorter and narrower than their perigynia; perigynia 55 to 80 per spike, 

512 



winged, when immature silvery-green, scalelike and subappressed, at maturity 
brownish and plano-convex, very firm, with tip erect, ventrally veiny, (3-) 3.5-4.2 
(-4.5) mm. long, 1.7-2.5 mm. broad (including the wings), broadest near the 
middle (meaning in the upper half of the "body"), the broadly triangular "beak" 
about 1 mm. long and scarcely differentiable from the "body"; achene lenticular, 
about 1.5 mm. long, 0.8 mm. wide. 

Infrequent in mud and shallow water in e. and s.e. Tex., Apr.-early June; 
Coastal States, Mass. to Tex., Ind., Mich.; Mex., Berm., also reported in Venez. 

26. Carex alata Torr. Fig. 263. 

Tufted perennial rather like C. Longii but the inflorescence perhaps on the 
average with the spikes a little more separated from each other; perigynia (3.7-) 
4-5 mm. long, 3.1-3.5 mm. broad, thus averaging longer and proportionately 
broader than in C. Longii, and with the ventral veins slightly less conspicuous. 

Rare in mud and wet sandy loam, e. Tex. (Anderson Co.) and Edwards 
Plateau (Sterling Co.), Apr.; otherwise attributed to Coastal States, Mass. to Fla. 
and Ind., Mich, and O. 

27. Carex hvalina Boott. 

Rhizomes 2-3.5 mm. thick, branching, black-fibrous, with internodes 0.5-1 
mm. long; culms 25-60 cm. long, about 1 mm. thick, erect, sharply triangular; 
sheath venters pale-hyaline; blades 1-2 mm. broad, shorter than (or the upper- 
most equaling) the culms; inflorescence 15-35 mm. long, 8-11 mm. thick, of 2 
to 4 noticeably separated sessile ascending gynecandrous subglobose (burlike) to 
prolate basally abruptly attenuate heads 8-12 mm. long and 8-11 mm. broad; 
scales much shorter than their perigynia; perigynia 15 to 30 per spike, divaricate, 
5.5-6.5 mm. long (including the beak), 2.5-3.2 mm. broad, widest well below 
the middle, the body (poorly differentiated) broadly ovate, widest near the 
middle, at anthesis pale-greenish-stramineous, membranous and distended only 
over the achene, at maturity very firm, unequally biconvex centrally and with 
the margins and wings strongly curved toward the ventral surface, stramineous 
with a brownish submarginal zone, strongly veined ventrally, with transverse 
wrinkles between the veins and in the margins and wings; beak poorly differen- 
tiated, elongate-triangular, 1.5-2 mm. long, green turning brownish; achene 
lenticular, about 2 mm. long, 1 mm. wide. 

Infrequent to rare in mud, Okla. (McCurtain Co.) and e. Tex. (Cass, Houston 
and Walker cos.), very rare in n.-cen. Tex. (Dallas Co.), Apr.-May; Ark., Okla. 
and Tex. 

28. Carex BickneUii Britt. 

Culms cespitose, slender, erect, exceeding the leaves, 5-10 dm. tall; principal 
leaf blades 2-4.5 mm. wide; spikes usually 4 to 6, the pistillate portion globose to 
ovoid, 8-12 mm. long, often distinctly clavate at base and to 18 mm. long (in- 
cluding the staminate portion), separate or somewhat aggregated in an oblong to 
linear cluster 3-7 cm. long; pistillate scales lance-ovate, shorter (1-2 mm.) and 
much narrower than the perigynia, pale-brown with green midnerve and narrow 
hyaline margins; perigynia broadly ovate, straw-color, 4.2-7.7 mm. long, 2.7-4.8 
mm. wide, very flat, thin and almost translucent, broadly winged, sharply several- 
nerved on both faces, abruptly contracted into the beak; achene lenticular, obo- 
vate, about 2 mm. long and 1.5 mm. wide. 

In wet or dry meadows, fields and open woods, in Okla. {Waterfall) and N.M.; 
Me. to Sask., s. to Del.. O., Mo., Okla. and N.M. 

513 




Fig. 263. a-e, Carex reniformis: a, inflorescence, X 1%; b. pistillate scale, X 8; c, 
perigynium, ventral view, X 8; d, perigyniiim, dorsal view, X 8; e, achene, X 8. f-i, 
Carex alata: f, inflorescence. X 1%; g, pistillate scale, X 8; h. perigynium, dorsal view, 
X 8; i, perigynium, ventral view, X 8. (Courtesy of R. K. Godfrey). 



29. Carex Brittoniana Bailey. 

Tufted perennial: rhizomes 2-4 mm. thick, black-fibrous, with internodes about 

1 mm. long, branching: culms 35-75 (-90) cm. long, 2-2.5 (-3) mm. thick, erect, 
sharply triangular; sheath venters stramineous-hyaline; blades 2.5-5 mm. broad, 
flat, shorter than the culms; inflorescence 25-50 mm. long, 10-25 mm. broad, of 

2 to 5 clumped or slightly separated ascending nearly globose to ovoid burlike 
basally strongly attenuate gynecandrous sessile spikes 11-16 mm. long; bracts 
essentially absent; perigynia (30 to) 40 to 50 (to 65) per bur, (5.5-) 6-8 (-8.5) mm. 
long (including the beak), (3.7-) 4-5.5 (-6) mm. broad (including the wings), at 
maturity divaricate, the body very broadly ovate to very broadly elliptic to nearly 
orbicular, occasionally broader than long, basally broadly rounded to slightly cor- 
date, at anthesis thin-membranous, pale-greenish-stramineous, distended only over 
the achene, at maturity firm to subcoriaceous, plano-convex centrally, stramineous 
with a submarginal brown zone, ventrally nearly veinless; beak 2.5-3 (-3.5) mm. 
long, strongly diff'erentiated, at anthesis green, at maturity brown, bidentate; 
achene lenticular, 2.5 mm. long, 2 mm. wide. 

In wet mud on edge of lakes, ponds and streams, in depressions in fields and in 
resacas, in Okla. (Waterfall) and in Rio Grande Plains, s.e. and n.-cen. Tex., 
infrequent in Edwards Plateau, Plains Country and e. Tex., Mar.-May. 

30. Carex reniformis (Bailey) Small. Fig. 263. 

Tufted perennial; culms 2-7 dm. long, 1-2 mm. thick, sharply triangular; 
sheath venters stramineous-hyaline; lower blades very short, upper ones 1.5-4 
mm. broad, shorter than the culms; inflorescence (1.5-) 3-4.5 (-5) cm. long, 7-10 
mm. thick, of 3 to 7 more or less strongly separate gynecandrous erect subglobose 
apically rounded basally abruptly attenuate spikes 6-10 (-13) mm. long and 5-8 
(-9) mm. broad; bracts essentially absent; scales half to two thirds as long as their 
perigynia; perigynia 25 to 40 per spike, erect, (3.3-) 3.8-5 (-5.5) mm. long (in- 
cluding the beak), (2.3-) 2.6-3.5 (-4.5) mm. broad, broadest near or below the 
middle, the bodies nearly orbicular to broadly oblong to obovate, winged, at 
anthesis extremely thin, distended only over the achene, membranous but at ma- 
turity firm to subcoriaceous, nearly plano-convex or concavo-convex, stramineous 
or with brownish submarginal staining, ventrally shiny and essentially veinless; 
beak well-differentiated from body, green turning pale-brownish, 1-1.7 mm. long, 
bidentate; achene lenticular, 2 mm. long, 1.5 mm. wide. C. brevior (Dew.) Mack. 

Frequent in s.e., e., and n.-cen. Tex., and N.M. (San Miguel Co.), in mud, 
occasionally in woodlands, usually in open places, Apr-May; e. N.A. w. to B.C., 
Wash., Ore., Colo., N.M. and Tex. 

31. Carex Hassei Bailey. Fig. 264. 

Rhizomes slender: culms 1-6 dm. tall, sharply triangular, roughened above, 
overtopping the leaves: leaves clustered near the base, channeled, 2-4 mm. wide, 
flat above; staminate spike terminal, solitary, peduncled, 6-15 mm. long, often 
pistillate at apex; pistillate spikes 2 to 4, linear-oblong, 8-20 mm. long, 3.5-4.5 
mm. wide, the upper spikes approximate and short-peduncled, the lower ones 
strongly separate and long-peduncled; lowest bract extending beyond the tip of 
the culm, scales broadly or narrowly ovate, the tips obtuse to acute or acuminate 
or often aristate with a scabrid awn, all these variations occurring within the 
same spike, the scales reddish-brown-tinged with green center and narrow hya- 
line margins; perigynia obovoid, at first greenish or straw-colored, becoming whit- 
ish and minutely granular, rounded and nearly beakless, the orifice entire; achenes 
lenticular, 1.5 mm. long, 1.2 mm. wide. 

Along streams, in wet meadows and in bogs, in Ariz. (Navajo and Coconino 
cos.) ; Alas. s. to Ariz, and Baja Calif. 

515 




Fig. 264: Carex Hassei: a, habit, showing separate pistillate and staminate spikes, 
the staminate spikes above, X -/::, b, scale of pistillate flower, X 6; c, scale of staminate 
flower, X 6; d, perigynium. rounded at apex, X 12; e, achene (cross section), X 12; f, 
pistillate flower with perigynium removed, X 12; g, ligule, X 8; h. inflorescence, the 
terminal spike staminate at base and pistillate at apex, the other spikes pistillate, X 3. 
(From Mason, Fig. 86). 




Fig. 265: Carex senta: a, staminate flower with subtending scale, X 10; b and c, 
scales of pistillate flowers, showing variation, X 10; d, pistillate flower with perigynium 
removed, X 12; e, achene (cross section), X 12; f, perigynium, broadly ovate, X 12; g, 
ligule, showing the long auricles, X 6; h, lower part of plant, showing filamentose 
lower sheaths, X -f,; i, upper part of culm, with short subtending bract, the lower spike 
pistillate, the upper spikes pistillate below and staminate above, X %. (From Mason, 
Fig. 92). 



32. Carex aurea Nutt. 

Perennial with extensive rhizomes several cm. long and 1 mm. thick; culms 
often weak and reclining basally, distally ascending, 7-20 cm. long, 0.5-0.8 mm. 
thick; leaves few, clustered basally; blades 15-25 cm. long and about 2 mm. broad, 
often surpassing the inflorescence; inflorescence of a terminal staminate spike 
and 2 or 3 subterminal weakly ascending peduncled (peduncle of lowest filiform 
one 1-2 cm. long, of upper ones shorter) lax pistillate spikes about 1 cm. long; 
bract of lowest spike leaflike, 3-10 cm. long, those of the higher spikes smaller; 
scales hyaline, minute, much smaller than their perigynia; perigynia 5 to 8 per 
spike, broadly ovate, plano-convex or lenticular, 2-2.5 mm. long, basally slightly 
narrowed, apically rounded, quite beakless, with a number of faint veins (2 of 
them less faint than the rest), membranous (when fresh somewhat succulent or 
baccate and translucent but drying firm, opaque in specimens), orange (in dried 
specimens rich-dark-brown); achene not quite filling the top of the perigynium 
(at least in dried specimens) but laterally filling it, lenticular, 1.5 mm. long, 1.3 
mm. wide, ovate, minutely apiculate, dark-brown, jointed with the style. 

Rare in seepy areas on shaded hillsides, and on edge of water of streams and 
ponds, in the Tex. Plains Country (Randall Co., Ceta Canyon), N.M. (Taos 
Co.) and Ariz. (Apache and Coconino cos.), June; temp. N.A., s. to Conn., 
Mich, and Neb. and at moderate elev. to Tex., N.M., Ut., Nev. and Calif. 

33. Carex crinita Lam. 

Tufted essentially glabrous perennial with branching scaly brownish rhizomes 
2-4 mm. thick; culms 6-12 dm. long, 2.5-5 mm. thick basally; basal sheaths dark 
brown, bladeless; blades of cauline leaves 5-11 mm. broad; spikes 4 or 5 per culm, 
overlapping, mostly nodding; terminal spike staminate, 3-5 cm. long, 2-3 mm. 
thick; subterminal spikes androgynous and progressively longer-peduncled down- 
ward; lowest spike essentially all pistillate or with only a very small terminal 
staminate portion, 4-9 cm. long, 5-10 mm. thick (including the scale cusps), 
with 75 to 130 close ascending perigynia, the scales with hyaline oblong bodies 
shorter than the perigynia but with the midnerve elongated into a spreading cusp 
surpassing the perigynium; bract of lowest spike sheathless, erect and usually 
much-surpassing the terminal spike, the higher bracts progressively reduced: 
perigynia obovate, 3-3.5 mm. long, biconvex, membranous, somewhat inflated, 
with 2 strong marginal nerves and a few vanishingly faint ones, stramineous to 
brownish, basally tapered, apically rounded or tapered and giving away abruptly to 
the minute tubular beak with entire orifice; achene biconvex, only half filling the 
perigynium, 1.5 mm. long, 1.3 mm. wide, apiculate, jointed with the 2-branchcd 
style which entirely withers after anthesis. Incl. var. MitchcUiana (M.A. Curtis) 
Gl. and var. brevicrinis Fern. 

Infrequent in wet places, usually in water, e. Tex. (Cass, Wood, Gregg and 
Morris cos.), May-June; e. N.A. w. to Man., Minn., Mo. and Tex. 

34. Carex senta Boott. Fig. 265. 

Cespitose from long stout horizontal rhizomes; culms rather slender but stiff, 
3-10 dm. high, sharply triangular and roughened on the angles, exceeding the 
leaves, brownish or reddish-brown at the base, the dried leaves of the previous 
year conspicuous; leaves 4 to 8 to a culm, septate-nodulose, clustered near the 
base, flat, channeled toward the base, the margins revolute toward the apex, 3-5 
mm. wide, the lower reduced, the upper much longer, papillate, ciliate-serrulate; 
sheaths hirsutulous, the lower breaking and becoming filamcntose, the ligule 
longer than wide and acuminate; staminate spikes 2 or 3, somewhat scattered, 
the terminal peduncled, 3-4.5 cm. long, 5 mm. wide, the lateral sessile, often 
vvith a few perigynia at the base; pistillate spikes 1 or 2, remote or approximate, 

518 



sessile or slightly peduncled, linear to oblong, 2.5-5 cm. long, 5-9 mm. wide, 
sometimes staminate at the apex, densely 25- to 100-flowered, the perigynia 
appressed-ascending; lowest bract leaflike, sheathless, usually exceeding the spike; 
scales linear-oblong to oblong-lanceolate, reddish-black with narrow one-nerved 
center, shorter than and about half as wide as the perigynia; perigynia much- 
flattened, plano-convex, broadly ovate to broadly obovate, 3-3.5 mm. long, 2-2.3 
mm. wide, granular-roughened, puncticulate, straw-colored, often strongly red- 
dish-brown-tinged, slenderly few-nerved on both surfaces and with two marginal 
ribs, round-tapering to truncate at the short-stipitate or sessile base, round-tapering 
at the apex, the margins entire or minutely serrulate, abruptly apiculate, the 
dark-tinged beak 0.25 mm. long, the orifice entire; achenes lenticular, broadly 
obovoid, 1.5 mm. long, 1 mm. wide, apiculate. 

Swampy habitats, in water of ponds and on wet cliffs in N.M. (Catron Co.) 
and Ariz. (Apache, Coconino, Maricopa and Cochise cos.); also Calif. 

35. Carex aquatilis Wahl. 

Cespitose, often in large clumps, sending forth scaly horizontal rhizomes; culms 
erect, slender, 1-10 dm. high, from obtusely triangular and smooth to sharply 
triangular and smooth or scabrous above, usually exceeding the leaves, phyllopodic, 
reddish-tinged at the base, the dried leaves of the previous year usually conspic- 
uous; leaves 8 to 15 to a culm, on the lower third, often more or less septate-nodu- 
lose (especially the sheaths), flat or channeled at the base, light-green or glaucous- 
green, erect-ascending, long-tapering, 2.5-8 mm. wide; sheaths slightly hispidulous 
or smooth dorsally, thin, reddish- or brownish-dotted and early ruptured ventrally, 
the ligule longer than wide; staminate spikes 1 to 3, linear, the upper peduncled, 
1.25 cm. long, 2-3 mm. wide, the others sessile or nearly so and shorter, some- 
times pistillate at the base; pistillate spikes 2 to 6, the upper often staminate at the 
apex, the lowest often strongly separate and occasionally on very long peduncles 
arising from near the base of the plant, the upper more or less approximate, and 
sessile to short-peduncled, erect, linear to oblong, 1-4 cm. long, 2.5-4 mm. wide, 
densely 20- to 100-flowered or somewhat attenuate at the base, the perigynia 
appressed-ascending; lowest bract leaflike, sheathless, normally exceeding the 
culm, the upper reduced; scales ovate to oblong-ovate, 1-2 mm. wide, obtuse and 
normally much narrower and shorter than the perigynia, blackish with lighter 
midrib and very narrow hyaline margins, not puncticulate and not enveloping the 
perigynia; perigynia unequally biconvex, strongly flattened, not at all turgid, oval 
to obovate, 2.5-3 mm. long, 1.25-1.75 mm. wide, nerveless or obscurely few- 
nerved except for the two marginal ribs, puncticulate, glandular-dotted, light- 
green to straw-colored or brownish, rounded and substipitate at the base, rounded 
at the apex and abruptly apiculate, the beak entire, 0.1-0.3 mm. long; achenes 
lenticular, broadly obovoid, about 1.6 mm. long and 1.2 mm. wide, yellowish and 
broadly substipitate, abruptly short-apiculate. 

In swamps, marshes, wet meadows, lake and pond shores and stream banks, 
often in shallow water, in N.M. (Colfax and Taos cos.) and Ariz. (Apache Co.); 
Greenl. to Alas., s. to Que., N.M., Ariz, and Calif.; Euras. 

36. Carex Kelloggii W. Boott. 

Cespitose, forming medium size to large clumps, the slender rootstocks short 
to more or less elongate; culms 1-6 dm. high, erect, slender, usually shorter 
than but sometimes exceeding the leaves, phyllopodic (sterile shoots aphyllopodic), 
brownish and somewhat fibrillose at the base, the dried leaves of the previous year 
conspicuous; leaves 5 to 10 to a culm, more or less clustered on the lower one- 
third, erect, thin, flat above, channeled toward the base, 1.5-2.5 mm. wide, long- 
attenuate; sheaths yellowish-brown-dotted ventrally, concave at the mouth, the 
ligule longer than wide; terminal spike staminate, rarely somewhat pistillate, more 

519 




Fig. 266: Carex nebraskensis: a, pistillate flower with perigynium removed, X 12; 
b, scales of pistillate flowers, X 12; c, scales of staminate flower, X 12; d, achene (cross 
section), X 12; e, perigynium, flattened and strongly many-ribbed. X 12; f and g, 
ligiiles, sometimes punctate, X 6; b, habit, upper part of plant, showing the leaves, the 
culm and the inflorescence with the spikes staminate above and pistillate below, the 
subtending bracts short, X %; i. lower part of plant, showing the stout horizontal 
rhizomes, X %. (From Mason, Fig. 94). 



or less strongly ^eduncled, 1-4 cm. long, 3-4 mm. wide; pistillate spikes 3 to 5, 
approximate or slightly separate, erect, the lower short-peduncled, the upper 
sessile or subsessile, linear-cylindric, often attenuate at the base, 1.5-3.5 cm. long, 
about 4.5 mm. wide, the numerous perigynia appressed-ascending; lowest bract 
leaflike, much-exceeding the inflorescence, usually sheathless or nearly so, the 
upper reduced, auriculate; scales oblong-ovate, obtuse or somewhat acute, dark- 
reddish-brown with narrow hyaline margins and a broad lighter usually one-nerved 
center not extending to the apex, narrower and shorter than to equaling the 
perigynia; perigynia early-deciduous, ovate, flattened-biconvex, sharply 2-edged, 
1.5-3 mm. long, 1.25 mm. wide, light-green, granular, membranaceous, 2-ribbed, 
truncate at the slenderly stipitate base, rounded at the abruptly apiculate-beaked 
apex, the beak 0.1-0.25 mm. long, entire, usually conspicuously black-tipped; 
achenes lenticular, suborbicular, about 1 mm. long, blackish, granular, substipi- 
tate, abruptly short-apiculate. 

On rocky lake margins, wet banks and in moist to marshy meadows, in Ariz. 
(Coconino Co.); Alta. to Colo, and Ariz., w. to Alas, and Calif. 

37. Carex nebraskensis Dewey. Fig. 266. 

Cespitose with long stout horizontal rhizomes; culms 2-10 dm. tall, papillate, 
sharply triangular, roughened or smooth above; leaf blades pale-green, 3-8 mm. 
wide, flat, the lower sheaths usually prominently septate-nodulose; terminal 
staminate spike 1.5-4 cm. long, 3-6 mm. wide, often with 1 or 2 smaller ones 
near its base, the lateral ones sessile or short-peduncled; pistillate spikes 2 to 4, 
erect, the upper one sessile or nearly so, the lower ones short- or long-peduncled, 
all contiguous or the lower ones somewhat separate, oblong to cylindric, 1.5-5 cm. 
long, 5-9 mm. wide; lowest bract leaflike, not sheathing, often dark- or light- 
auricled, varying from extending slightly beyond to not reaching the tip of the 
inflorescence; scales lanceolate, obtusish to acute or acuminate, narrower than 
and from shorter than to longer than perigynia, purplish or brownish-black with 
lighter center and often with narrower hyaline margins; perigynia flattened, ob- 
long-ovate to broadly ovate or obovate, 3-3.5 mm. long, 2 mm. wide, strongly 
many-ribbed on both faces, greenish to straw-colored or brownish at maturity, 
abruptly apiculate at apex, the beak often dark-tipped; achenes lenticular, nearly 
orbicular, 1.5 mm. long. 

In mud along sloughs, streams and in seepage areas, wet meadows and marshes, 
in N.M. (Taos and Rio Arriba cos.) and Ariz. (Apache, Coconino and Mohave 
cos.); S.D. to B.C., s. to Kan., N.M., Ariz, and Calif. 

38. Carex stricta Lam. 

Perennial in large tufts, with slender easily detached rhizomes; culms 3-8 dm. 
long, 1-2 mm. thick basally, the basal sheaths chestnut-black; juncture of sheath 
and blade V-shaped; spikes usually 4 per culm, overlapping or occasionally the 
lowermost slightly remote: uppermost spike erect and usually entirely staminate, 
2-4 cm. long, 2.5-4 mm. thick, buffy-brown; subterminal spikes usually sessile, 
androgynous and slightly nodding (at maturity); lower spikes usually almost en- 
tirely pistillate, 2-4 cm. long, 3-4 mm. thick, with 45 to 65 overlapping ascend- 
ing perigynia (borne in elegant rows) and brownish oblong blunt scales with 
paler mid-nerve and slightly shorter than their perigynia to which they are closely 
appressed; bracts sheathless, that of the lowest spike often attaining the uppermost 
spike in length, those of higher spikes progressively drastically reduced; perigynia 
ovate, flattened (biconvex), 2.5-3 mm. long, olivaceous, with 2 strong (marginal) 
nerves and a few vanishingly obscure ones, firm-membranous, basally rounded, 
shortly tapered to an essentially beakless or minutely beaked apex, the orifice 
essentially entire; stigmas 2; achene lenticular, only about half filling the perigyn- 

521 



ium, 1.7 mm. long, 1.3 mm. wide, apiculate, jointed with the style which entirely 
withers after anthesis. 

Rare in moist sandy forests and bogs, e. Tex. (Freestone and Walker cos.), 
Apr.-May; N.E., N.Y. and Pa. s. to N.C.; also Ind., Mich., Wise, 111., Minn, 
and Tex. 

Our plants have longer, fewer perigynia than plants from most of the range 
in northeastern United States and perhaps should be a different name. 

39. Carex Emoryi Dew. 

Perennial in large tufts and in tufts with extensively creeping scaly rhizomes 
2-3 mm. thick; culms 4-10 dm. long, 2-3 mm. thick basally, remainder of 
leaves mostly clustered basally; basal sheaths light chestnut to purplish; juncture 
of sheath and blade flat or slightly arcuate; spikes 4 to 7 per culm, overlapping 
or rarely slightly remote; uppermost spike nearly erect and usually entirely or 
nearly entirely staminate, 2.5-7 cm. long, 2.5-4 mm. thick, brownish-stramineous; 
lower spikes usually sessile, androgynous, slightly nodding (at maturity); lowest 
spikes usually almost entirely pistillate. 3-10 cm. long, 3.5-5 mm. thick, with 
65 to 165 overlapping ascending perigynia (borne in rows); bracts sheathless, 
that of the lowest spike 1.5-4 mm. broad and (in length) often attaining the 
uppermost spike, the higher bracts progressively drastically reduced; scales 
brownish-hyaline, oblong, blunt, with paler broad midnerves, shorter than the 
perigynia to which they are closely appressed; perigynia ovate to obovate, flat- 
tened (biconvex), 2.3-3.3 mm. long, stramineous, with 2 strong (marginal) nerves 
and a few vanishingly obscure ones, firm-membranous, basally rounded, shortly 
tapered to an essentially beakless or minutely beaked apex, the orifice essentially 
entire; stigmas 2; achene lenticular, only about half filling the perigynium, 1.5 mm. 
long, 1 mm. wide, apiculate, jointed with the style which entirely withers after 
anthesis. 

Frequent in calcareous mud, n.-cen. and Trans-Pecos Tex. and Edwards Plateau, 
and N. M. (Mora Co.), Apr.-May; Man. and N.D. s. to Coah. and Tex., e. to 
N.Y., N.J., D.C. and Va. 

Perhaps only a variety of C. stricta. 

40. Carex ultra Bailey. 

Densely cespitose from very stout rootstocks; culms stout, erect, much-exceed- 
ing the leaves, 5-15 dm. high, 1.5 cm. thick at the base, smooth on the obtuse 
angles below, serrulate on the sharp angles in the inflorescence, brownish-tinged 
at the base; leaves 6 to 15 to a culm, not septate-nodulose, thick, glaucous, 6-12 
mm. wide, channeled at the base, flat above with more or less revolute margins, 
conspicuously striate-nerved, strongly rough-serrulate on the margins; lower sheaths 
rough, scabrous and filamentose ventrally, concave at the mouth, the ligule longer 
than wide; staminate spikes 2 to 4, approximate or more or less separate, 3-12 
cm. long, 4-6 mm. wide, the lateral sessile or short-peduncled; pistillate spikes 3 
to 6, sometimes staminate at the apex, the upper sessile and overlapping, the lower 
more or less strongly peduncled and separate, erect, elongate, linear-cylindric, 
2.5-15 cm. long, 6-12 mm. wide, containing very numerous appressed-ascending 
perigynia; bracts leaflike, the lower short-sheathing and sometimes exceeding the 
inflorescence, the upper shorter; scales lanceolate, acute to acuminate or taper- 
ing into a short rough awn, reddish-brown, the center several-nerved and green 
or straw-colored, half as wide as the perigynia; perigynia compressed-trigonous, 
broadly obovoid, 3.5-4.5 mm. long, 2 mm. wide, little-inflated, subcoriaceous, 
glabrous, light-brown, red-striolate at maturity, obscurely several-nerved on both 
surfaces, rounded at the base and apex, abruptly short-beaked, the beak 0.3 mm. 
long, the apex emarginate; achenes trigonous with blunt angles, elliptic-obovoid, 

522 




Fig. 267: a-c, Carex Frankii: a, top of plant, X V2; b, perigynium, X 5; c, achene, 
X 5. d-g, Carex hyalinolepis: d, habit, X Vr,; e, top of plant, X Vi; f, perigynium, X 5; 
g, scale, X 5. (a, d-g. Courtesy of R. K. Godfrey; b and c, V. F.). 




Fig. 268: Carex tvphina: a, inflorescence, X V-y; b, scale, X 5; c, perigynium, X 5. 
(Courtesy of R. K. Godfrey). 

about 2.5 mm. long and 1.25 mm. wide, silvery-black, minutely pitted, substipi- 
tate, abruptly contracted into the slender straight style. 

Springy places in N. M. (Grant Co.), and Ariz. (Apache, Pinal, Cochise and 
Santa Cruz cos.) ; also n. Mex. 

41. Carex Frankii Kunth. Fig. 267. 

Perennial with extensively creeping rhizomes 1-2 mm. thick; culms 2-7 dm. 
long, 1.5-5 mm. thick basally; basal sheaths brownish, rarely rosy; blades 4-11 
mm. broad; inflorescence of 4 to 6 ascending spikes; terminal (often exceedingly 
inconspicuous) spike staminate, 3-50 mm. long, 1.5-5 mm. thick, stramineous or 
brown; the remaining spikes pistillate, the upper ones overlapping and short- 
peduncled but the lowest commonly remote with a peduncle to 15 cm. long, 1-4 
cm. long, 8-15 mm. thick, bristly, with 25 to 130 very close spreading perigynia; 
bracts sheathing, foliaceous, the blade of the lowest one commonly far-exceeding 
the inflorescence, the higher ones progressively reduced; scales as long as or 
longer than the perigynia with the distal part being a wiry awn or bristle; perigynia 
3.5-5.5 mm. long, with obovoid bodies 2-4 mm. long, olivaceous, inflated, mem- 
branous, with 10 to 15 nerves much more slender than the internerve spaces, 
basally tapered and narrowly rounded, apically abruptly short-conic and well- 
diff'erentiated from the subulate beak (about 1.5 mm. long) and with a strongly 
bidentate orifice; achenes triangular, 1.5-2.2 mm. long, about 1.5 mm. wide, con- 
tinuous with the persistent very slender usually straight style which in its lower 
half has much the same texture as the achene. 

In marshes, boggy areas and mud in seepage areas, edge of streams and about 
ponds, in Okia. (Johnston, Adair, Murray, Mayes, Washington, Haskell, Atoka, 
Pittsburg, Pushmataha and Cherokee cos.) and in e. and s.e. Tex., infrequent in 
n.-cen. Tex., rare in the Trans-Pecos (Franklin and Davis Mts.), in seeps and 



524 



springs, Apr-June (to July in Trans-Pecos); s.e. U.S. n. to N.Y., 111. and Kan.; 
also Coah. and parts of s. S.A. 

42. Carex typhina Michx. Fig. 268. 

Perennial; rhizomes black, scaly, 2-5 mm. thick, \—i cm. long between culm- 
tufts; culms 3-8 dm. long, 1.5-4 mm. thick basally; lower sheaths brown; blades 
3-7 mm. broad; spikes 1 to several, terminal gynecandrous, 3-4 cm. long, 12-15 
mm. thick including the beaks, with a cylindric (slightly ovoid) terminal pistillate 
portion of 60 to 110 closely packed spreading perigynia, basally abruptly acumi- 
nate to the inconspicuous staminate portion; bracts sheathless, the blade surpassing 
the spike; pistillate scales narrowly obovate to oblanceolate, apically acute but 
not mucronate, laterally hyaline; perigynia about 6 mm. long, the obovoid bodies 
4-5 mm. long, inflated, brownish, brittle-membranous, shiny, with 2 faint nerves 
distally, basally narrowed and shortly rounded, apically abruptly short-conic to 
the subulate or linear bidentate spreading or usually very slightly ascending beak; 
achene triangular, 3 mm. long, 1.5 mm. wide, occupying only a small portion of 
the perigynium, apically acute, continuous with the persistent slender abruptly 
sinuous style whose proximal part is texturally like the achene. C. squarrosa L. 
var. typhina (Michx.) Nutt. 

In swamps and low wet woodlands, river bottomlands and wet sandy loam, rare 
in e. Tex. (Harrison and Shelby cos.), July-Sept.; Que. and n.e. U.S. s. toS.C, Ky. 
and La., w. to Wise, la.. Mo. and Tex. 

May not be specifically distinct from C. squarrosa. 

43. Carex squarrosa L. 

Culms cespitose, 3-8 dm. tall; principal blades 3-6 mm. wide; spikes usually 
solitary, occasionally 2, rarely 3, the upper two-thirds pistillate, the lower third 
staminate; pistillate portion elliptic, 1-3 cm. long, 1-2 cm. thick, rounded at 
both ends, very densely flowered; lateral spikes (if present) pistillate, smaller, 
erect on short peduncles; bracts of the terminal spike short and narrow, of the 
lateral ones foliaceous; staminate scales acute or acuminate; pistillate scales mostly 
concealed, acuminate or short-awned; perigynia obconic or conic-obovoid, 3.5-7 
mm. long, its summit with two strong ribs (the lateral) and a few obscure nerves; 
beak 2-3.5 mm. long, its teeth 0.2 mm. long; achenes trigonous, blackish with 
iridescent superficial cells (when fully mature), 3 mm. long, 1.5 mm. wide, base 
of the style greatly curved. 

In wet meadows, swamps, wet swales and alluvial floodplains in Okla. (Water- 
fall) •. w. Que. and Conn, to Wise, and Neb. s. to N. C, Ark. and Okla. 

44. Carex hyalinolepis Steud. Fig. 267. 

Perennial with extensively creeping rhizomes 2-5 mm. thick; culms single at 
the nodes of the rhizome, 4-8 dm. long, 5-8 mm. thick basally; leaves mostly 
crowded toward the base; basal sheaths yellowish-stramineous; blades 4-13 mm. 
broad, tough, with noxious serrulate edges; spikes 4 to 6 (to 8) per culm, the 
upper 1 to 3 staminate and sessile, the lower 1 to 4 short-peduncled, erect and 
pistillate, often with an androgynous spike at an intermediate level; terminal 
spike 3-6 cm. long, 3-6 mm. thick; lowest pistillate spike 3-8 cm. long, 11-15 
mm. thick, with 70 to 100 ascending perigynia (overlapping closely except occa- 
sionally the lowest 2 or 3), the scales much shorter than their perigynia; bracts 
foliaceous, short-sheathing, that of the lowest commonly surpassing the entire 
inflorescence, the higher ones progressively reduced; perigynia 6-9 mm. long, 
ampulelike or very narrowly ovate, in transection elliptic, stramineous-brown to 
olive-brown, tough-membranous, eventually becoming tough-chartaceous, with 20 
to 25 very faint (vanishing in some specimens) nerves much narrower than the 
spaces between them, slightly inflated, basally rounded, in the upper half slightly 
acuminate to a scarcely beaklike firm bidentate apex; achene triangular, up to 

525 




Fig. 269: Carex comosa: a, perigynium, showing the numerous strong ribs and the 
spreading bidentate beat;, X 8; b, achene (cross section), X 12; c. pistillate flower with 
perigynium removed, showing the very long style and the 3 short stigmas, X 12; d, 
scale of pistillate flower, showing the long scabrid awn, X 12; e. upper part of culm, 
showing the leaflike bracts and the nodding pistillate spikes. X I'l; f. ligule, X 2; g, 
lower part of plant, showing the stout erect culms and leaf blades, X li; h, staminate 
flower, the subtending scale scabrid, X 6. (From Mason, Fig. 120). 



2.5 mm. long, 1.5 mm. wide, continuous with the basally curved style which 
basally has the same porcelaneous texture as the achene. 

In wet meadows, swamps, ditches, edge of sloughs, lakes and ponds, and in 
mud of streams in Okla. (Waterfall) and in s.e. (Brazoria and Colorado cos.), e. 
(Bowie and Gonzales cos.) and n.-cen. (Dallas and Tarrant cos.) Tex., Apr-May; 
Ont. and e. U.S. w. to Mich., Neb., Okla. and Tex. 

45. Carex comosa Boott. Bristly sedge. Fig. 269. 

Mat-forming perennial with short branching rhizomes; culms 5-13 dm. long, 
erect, 3-10 mm. thick basally; lower sheaths brownish-stramineous; blades 6-12 
mm. broad; spikes 4 or 5 per culm, overlapping for most of their lengths; upper- 
most spike staminate, 25-50 mm. long, 3-5 mm. thick, brownish-stramineous; 
lower spikes pistillate, nearly horizontal by virtue of a sharp bend at the top of 
each peduncle, bristly, the lowest one 35-50 mm. long, 12-15 mm. thick, with 65 
to 130 spreading or even slightly deflexed close perigynia; bracts sheathless, the 
lowest one with a blade far-surpassing the inflorescence the rest progressively 
reduced; pistillate scales with very small pale brown bodies with the pale mid- 
veins extending into rough awns usually shorter than the perigynia, deciduous 
with the perigynia; perigynia lance-acuminate, in transection vaguely triangular 
or somewhat dorsiventrally flattened, 4-7 mm. long, stramineous, firm-membra- 
nous, with 2 ribs and 14 or 15 prominent nerves slightly narrower than the spaces 
between, basally narrowly rounded, acuminate into a slender beak almost as long 
as the very slightly inflated body and with 2 terminal arcuate-divaricate teeth; 
achene triangular, about 1.5 mm. long, 1 mm. wide, apically continuous with the 
long slender persistent style which proximally has much the same porcelaneous 
texture as the achene itself. 

Rare in lakes, marshes and ponds, in e. Tex. (Wood Co.), Apr.-June; otherwise 
s.e. Can. and e. U.S. w. to Minn., Neb., Mo. and Tex.; also Ida., Wash., Ore. and 
Calif. 

46. Carex hystericina Muhl. Porcupine caric-sedge, bottle-brush caric-sedge. 

Perennial with rhizomes 1.5-2.5 mm. thick and several cm. long; culms tufted 
at intervals along the rhizome, 2-8 dm. long, 1-3.5 mm. thick, erect; lower sheaths 
stramineous, rarely with a reddish-tinge; blades 2.5-9 mm. broad; spikes 3 to 4 
(to 6) per culm, mostly overlapping or the lower one or 2 somewhat remote; upper- 
most spike staminate (rarely androgynous), 15-35 mm. long, 3-4 mm. thick, 
stramineous; lower spikes pistillate (some upper ones infrequently androgynous), 
bristly, the lowest one erect or nodding slightly, 15-35 mm. long, 8-12 mm. thick, 
with 35 to 70 close spreading (at maturity) perigynia; bracts sheathless, the blades 
of the lowest one often surpassing the terminal spikes, the higher ones progressively 
much-reduced; the stramineous scales almost as long as the perigynia and with 
ovate hyaline bodies and long subulate cusps or awns; perigynia lance-acuminate, 
in transection nearly round or (when immature or pressed) dorsiventrally flattened, 
5-7 mm. long, stramineous-membranous, with 2 nerves or weak ribs and 12 to 14 
fine nerves much narrower than the spaces between them, basally narrowly 
rounded, acuminate into a slender strongly bidentate beak about half as long as 
the inflated body; achene triangular, about 1.8 mm. long, 1.2 mm. wide, the 
sides concave in the lower part, continuous with the long persistent slender style 
which basally has much the same porcelaneous texture as the achene itself. 

In swampy meadows and in calcareous mud of stream beds in Okla. ( Waterfall) 
and Tex., in the mts. of the Trans-Pecos, rare e. to the Plains Country and Edwards 
Plateau, N. M. (San Miguel Co.) and Ariz. (Apache, Navajo, Coconino and Mari- 
copa COS.), summer; s. Can. and n. U.S. s. to Va., Ky., Okla., Tex., N.M., Ariz, 
and Calif; Coah. Sometimes incorrectly spelled "hystricina". 

527 




Fig. 270: Carex lurida: a, habit. X I'x. b, ligule, X IM^; c, staminate scale, X 4; d, 
pistillate scale, X 4; e, perigynium, X 4; f, achene, X 8. (Courtesy of R. K. Godfrey). 



47. Carex Thurberi Dewey. 

Cespitose from stout rootstocks; culms 6-12 dm. high, phyllopodic, erect, stout, 
shorter than the leaves and bracts, sharply triangular, reddish-tinged at the base, 
the lower sheaths breaking and becoming filamentose; leaves 5 to 10 to a culm, 
obscurely septate-nodulose, the blades flat with revolute margins, thin but rather 
stiff, 4-8 mm. wide, long-attenuate, very rough toward the apex; sheaths sparsely 
hispidulous dorsally, concave and short-hispid at the mouth, the short ligule much 
wider than long; terminal spike staminate, erect, short-peduncled, linear, 4-8 cm. 
long, 3-5 mm. wide; pistillate spikes 3 or 4, approximate or more or less sepa- 
rate, drooping or the upper weakly erect on rough slender peduncles mostly 
shorter (except the lowest) than the spikes, the spikes oblong-cylindric or cylindric, 
3.5-7 cm. long, 8-10 mm. wide, densely 50- to 100-flowered, the perigynia 
ascending or spreading-ascending; bracts leaflike, sheathless or very nearly so, 
much-exceeding the inflorescence; scales ovate, often emarginate, strongly rough- 
awned, the body large, ciliate-serrulate above, hyaline and slightly reddish-brown- 
tinged, the green center three-nerved, nearly as wide as but much shorter than the 
perigynia; perigynia elliptic-ovoid, 4-5 mm. long, 1.5 mm. wide, slightly inflated, 
suborbicular to obscurely triangular in cross section, submembranaceous, puncti- 
culate, yellowish-green, finely several-ribbed, rounded at the short-stipitate base, 
tapering into a smooth strongly bidentate beak 1.5 mm. long, the slender stiff 
teeth slightly spreading, 0.5-0.75 mm. long; achenes trigonous with blunt angles, 
oblong-obovoid, about 1.75 mm. long and 0.75 mm. wide, substipitate, continuous 
with the slender abruptly bent persistent style. 

In moist or wet ravines and swampy habitats, in Ariz. (Coconino, Gila, Cochise, 
Santa Cruz, and Pima cos.); Ariz, to Guat.; W.I. 

48. Carex lurida Wahl. Fig. 270. 

Tufted perennial with very short rhizomes; culms 3-10 dm. long, 1.5-6.5 mm. 
thick, erect, leafy; basal sheaths brown (occasionally faintly reddish); blades 4-10 
mm. broad; spikes 3 to 5. mostly overlapping or occasionally the lower 1 or 2 
slightly removed; terminal spike staminate, erect, 3-6 cm. long, 1-2 mm. thick; 
rest of spikes pistillate, nearly sessile (or the lower occasionally on flexuous 
peduncles to 19 cm. long), often arcuate-nodding, the lowest 25-40 (-60) mm. 
long, 14-18 (-20) mm. thick including beaks, with 50 to 80 (to 100) close some- 
what ascending perigynia; bracts foliaceous, sheathing, the blade of the'lowest one 
much-surpassing the entire inflorescence; the scales about as long as the bodies of 
the perigynia and subulate or awnlike in their distal part; perigynia ampule-shaped, 
7-11 mm. long, the bodies ovoid or obovoid, 2.3 mm. thick, 4-6 mm. long, in- 
flated, membranous, olive-green, drying to olive-brown or olive-stramineous, with 
8 to 1 1 nerves (2 slightly stronger than the rest) much narrower than the internerve 
spaces, basally tapered and shortly rounded, apically tapered or long-conic and 
passing gradually into the linear-subulate bidentate beak; achene triangular, about 
2.5 mm. long, 1.5 mm. wide, granular, continuous with the sinous-flexuous per- 
sistent style the lower half of which is texturally similar to the achene. 

Wet meadows, marshes, seepage, edge of streams and ponds in sand and mud, 
in Okla. (McCurtain and LeFlore cos.) and e. Tex., May-June; e. temp. N.A. w. 
to Minn., Mo., Okla. and Tex.; also Ver. 

49. Carex vesicaria L. Inflated sedge. Fig. 271. 

Rhizomes short-creeping, stout; culms 3-9 dm. tall, sharply triangular and 
rough above, the lower leaves more or less bladeless; leaf blades flat, 2-6 mm. 
wide, more or less strongly nodulose on abaxial surface; staminate spikes 2 to 4, 
2-4 cm. long, 2.5-4 mm. wide, the upper one peduncled, the lateral ones sessile; 
pistillate spikes 1 to 3 (usually 2), 2-7.5 cm. long, 5-15 mm. wide, oblong- 

529 



<\^ 




Fig. 271: Carex vesicaria: a, lower part of plant, showing the bladeless lower 
leaves and the rhizomatous base of plant, X -f,; b, upper part of culm, showing the 
long bracts, the sessile pistillate spikes below and the terminal staminate spikes above. 
X %; c, staminate flower and subtending scale. X 5; d, scale of pistillate flower, X 5; 
e, perigynium, showing bidentate beak with erect teeth, X 5; f, ligule, X 11-.; g. pistil- 
late flower with perigynium removed, showing the very long and flexuous style, X 5; h, 
achene (cross section), X 5. (From Mason, Fig. 121). 




Fig. 272: Carex rostrata: a, staminate flower and subtending scale, X 8; b, peri- 
gynium, showing the slender erect bidentate beak. X 8; c. ligule, X 6; d, pistillate flower 
with perigynium removed, showing the substipitate achene and curved style, X 12; e, 
achene (cross section), X 12; f, habit, lower part of plant, showing the long horizontal 
rhizomes, X %; g, upper part of culm, the lower spikes pistillate, the staminate spikes 
terminal, some of the staminate spikes bearing perigynia at apex, X %; h, scale of 
pistillate flower, X 8. (From Mason, Fig. 122). 



cylindric, sessile or short-peduncled, widely separate; bracts leaflike, not sheathing, 
the lowest extending well beyond the tip of the culm; scales ovate-lanceolate, acute 
to acuminate or short-awned, reddish-brown-tinged with green center and narrow 
hyaline margins, one half to nearly as long as the perigynia; perigynia ovoid, 
inflated, 4-8 mm. long, 3 mm. wide, yellowish-green or brownish, ascending or 
ascending-spreading at maturity, the smooth bidentate beak 1.5-2 mm. long, the 
erect teeth 0.5-1 mm. long; achene trigonous, with blunt angles, 2.5 mm. long, 
1.7 mm. wide, obovoid, substipitate, contracted at the apex into the persistent 
abruptly bent style. 

Wet meadows, swampy open ground or woods, forested floodplains, low wet 
river bottoms, in N.M. (Otero, Sandoval, Rio Arriba and Taos cos.) and Ariz. 
Coconino Co.); Nfld. to B.C., s. to Del., Ind., Mo., N.M., Ariz, and Calif.; Euras. 

50. Carex rostrata Stokes. Beaked sedge. Fig. 272. 

Closely resembling C. vesicaria, with which it possibly intergrades, but differing, 
at least in its typical aspect, in the following features: rhizomes producing long 
horizontal stolons; culms obtusely angled; lower leaves with well-developed blades; 
leaves more or less strongly septate-nodulose (at least on the sheaths), the blades 
2-12 mm. wide; basal sheaths little if at all filamentose; perigynia 3.5-8 mm. long, 
2.5-3.5 mm. wide, at maturity ascending-spreading or spreading, the lowest some- 
times reflexed; achenes trigonous with blunt angles, obovoid, 2 mm. long, 1.2 mm. 
wide. C. inflata Huds. 

In marshes and bogs, in water of pools, ponds and lakes, along streams and 
in seepage area about springs, in N.M. (Rio Arriba and Taos cos.) and Ariz. 
(Apache and Coconino cos.); Greenl. to Alas., s. to Del., Ind., N.M., Ariz, and 
Calif. 

51. Carex folliculata L. var. australis Bailey. Fig. 273. 

Tufted perennial; culms 4-8 dm. long. 2-4 mm. thick basally, erect; basal 
sheaths whitish, nodulose; blades 5-10 mm. broad; spikes 3 or 4 per culm.' remote 
except for sometimes the 2 upper ones; the uppermost spike staminate, 2-4 cm. 
long, 2-3 mm. thick, stramineous; next lowest spike pistillate (or with a very short 
terminal staminate portion), nearly sessile; lower spikes progressively longer- 
peduncled and all pistillate, erect; lowest spike 15-27 mm. long. 15-23 mm. 
broad, with 12 to 20 spreading perigynia (internodes of rachis about 1 mm. long); 
bracts leaflike, that of the lowest spike 15-25 cm. long including the sheath; higher 
bracts progressively reduced; the lance-acuminate scales hyaline-stramineous and 
5-7 mm. long; perigynia lance-subulate, not at all acuminate, nearly round in 
transection, 11-14 mm. long, greenish (drying stramineous), membranous, with 
15 to 25 strong nerves narrower than the internerve spaces, inflated; achene 
rounded-triangular with concave sides, up to 3.5 mm. long. 2 mm. wide, con- 
tinuous with the long persistent slender style which basally has much the same 
porcelaneous texture as the achene itself. C. lonchocarpa Willd. 

Infrequent or rare in e. Tex. (Hardin, Jasper. Newton and Tyler cos.), in wet 
sand or mud, Apr. -May, rarely as late as June, a few perigynia persistent into 
July; Coastal States, Va. to Tex. 

52. Carex Grayi Carey. 

Plants cespitose, usually 3-8 dm. tall; principal blades usually 2-3 dm. long. 
6-12 mm. wide; pistillate spikes 1 or 2 (rarely 3). when 2 close together, globose 
or nearly so, 2.5-4 cm. in diameter; pistillate scales ovate, much shorter than 
and mostly concealed by the perigynia; perigynia crowded, usually 15 to 20. dull, 
lance-ovoid, radiating in all directions, 12-18 mm. long, obconic from the base 
to the widest portion, thence tapering to the beak, usually hispidulous below the 

532 




Fig. 273: Carex foUicidata var. australis: a, inflorescence, X V^, b, scale, X 7; c, 
perigynium, dorsal view, X 7; d, perigynium, ventral view, X 7. (Courtesy of R. K. 
Godfrey). 




Fig. 274: a-d, Carex aigantea: a, inflorescence, X il); b, scales, X 5; c, perigynium, 
dorsal view, X 5; d, perigynum, ventral view, X 5. e-h. Carex intumescens: e, inflores- 
cence, X yo', f. scale, X 5; g, perigynium, X 5; h, achene, X 5. (Courtesy of R. K. 
Godfrey). 



middle; achenes trigonous with rounded angles, the body about 4 mm. long, 3 mm. 
wide; style persistent, straight or loosely contorted above the middle. 

Swampy woods, forested alluvial floodplains, and low wet river bottomland, 
in Okla. (Waterfall); Vt. to Wise., s. to Ga., Mo. and Okla. 

53. Carex intumescens Rudge. Fig. 274. 

Tufted perennial; culms 3-7 dm. long, basally 1.5-3 mm. thick, erect; basal 
sheaths reddish-brown; blades 2-5 mm. broad; spikes 2 to 4 per culm, clustered or 
remote; terminal spike staminate, 2-5 cm. long, 2-3 mm. thick, brownish; the 
remaining spikes pistillate, ascending, 13-22 mm. long, 14-25 mm. broad, with 8 
to 15 close spreading perigynia; bracts sheathing, foliaceous, surpassing the in- 
florescence; the narrowly ovate scales acute and only about half as long as their 
perigynia; perigynia 11-16 mrn. long, the body three-fourths to five-sixths the 
total length, ovoid to narrowly so, olivaceous, crusty-membranous, much-inflated, 
with 14 to 19 slender nerves, basally rounded, apically tapered and passing 
gradually into the proportionally short bidentate beak; ache