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¢ 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; achene longer than thick,
triangular, the angles not prominent and totally knobless, about 4 mm. long, 25
mm. wide, passing into the slender often looped style (the lower persistent part
of which texturally resembles the achene).
In moist areas, floodplain woods along streams, wooded swamps and alluvial
plains, in Okla. (Waterfall) and e. and s.e. Tex., Apr.-June; s.e. Can. and e. U.S.
w. to Minn.. la.. Mo., Ark. and Tex.
54. Carex lupulina Muhl.
Perennial, usually very loosely tufted and with creeping rhizomes 1-3 mm.
thick; culms 3-10 dm. long, erect, basally 1.5-10 mm. thick, the lower sheaths
brownish, occasionally with a slight rosy hue; blades 3-12 mm. broad; spikes
3 to 6 per culm, either clustered and overlapping or the lower remote, occasionally
all rather remote and the lower ones long-peduncled; upper spike (rarely upper 2)
staminate, 3-8 cm. long, 2-4 mm. thick, brownish; lower spikes pistillate, usually
cylindrical, less commonly oblong or ellipsoid-oblong, often slightly nodding
terminally, 2-5 cm. long. 15-24 mm. thick, the lowest with 25 to 80 close ascend-
ing or somewhat spreading perigynia; bracts sheathing, foliaceous, that of the
lowest spike commonly far-suroassing the inflorescence; scales mostly hyaline-
translucent, broadly lanceolate, acute, often mucronate, less commonly with an
awn about 2 mm. long, the whole only about half to two thirds as long as the
perigynia; perigynia 1 1-20 mm. long, the body about half to five eighths the total
length, broadly ovoid, stramineous to olivaceous, crusty-membranous, with 14 to
21 slender nerves, inflated, basally rounded, apically acuminate and passing
gradually into the long slender bidentate beak; achene longer than broad, about
3 mm. long, 2.5 mm. wide, triangular with more or less pronounced angles
(making the sides seem concave) and with more or less of a process or knob on
each angle (very indistinct in some plants), apically continuous with the violently
looped style whose lower persistent part texturally resembles the achene. C
lupuUformis Sartw., C louisianica Bailey.
In mud and shallow water of streams, in marshes and swamps, low roadside
ditches, in e. Okla. (Adair, Delaware, LeFlore, McCurtain, Ottawa, Pushmataha,
Creek, Osage and Haskell cos.) and e. and s.e. Tex., Apr. -May, occasionally into
early summer; N.S., Que. and Ont., e. U.S. w. to Minn., la., Mo., Okla. and Tex.
55. Carex gigantea Rudge. Fig. 274.
Loosely tufted perennial with creeping scaly rhizomes 1.5-3 mm. thick; culms
35-80 cm. long; basal sheaths brownish to stramineous; blades 4-12 mm. broad;
spikes 3 or 4 (rarely 5) per culm, usually all but the lowermost overlapping;
terminal spike staminate, 3-6 cm. long, 2-4 mm. thick; the remaining spikes
535
Fig. 275: Carex kptalea: a, pistillate flower with a part of the stipitate perigynium
attached, the achene obscurely trigonous, the style flexuous and the stigma bifid, X 16;
b, perigynium, many-striate and beakless, X 12; c, achene (cross section), X 16; d,
scale of pistillate flower, X 12; e, ligule, X 24; f, spike subtended by bractlike scale, the
inconspicuous staminate flowers at apex, X 6; g, scale of staminate flower, X 16; h,
habit, showing the very slender densely tufted culms extending above the leaves, X 7-,.
(From Mason, Fig. 108).
pistillate, cylindric, the lowest 3-5 cm. long, 14-22 mm. thick (including beaks),
with 30 to 65 close spreading perigynia; bracts sheathing, foliaceous, that of the
lowest spike far-exceeding the inflorescence; the lanceolate scales acute or acumi-
nate and about half to three fourths as long as the perigynia; perigynia 12-15 mm.
long, the body about three eighths the total length, ovoid, crusty-membranous,
inflated, olive-stramineous, with 14 to 17 slender nerves, basally rounded, apically
acuminate and passing into the long subulate bidentate beak; achene about as
broad as or usually broader than long, rhombic-triangular with very prominent
angles each with a pronounced knob near the middle, about 2 mm. long, 2.5 mm.
wide, apically continuous with the violently looped style whose persistent lower
part texturally resembles the achene.
In wooded swamps, alluvial floodplain woods, in and about ponds, lakes and
pools, in Okla. (Waterfall) and e. and s.e. Tex. (Harris and Polk cos.), May-
July; lowlands of s.e. U.S. n. to Del., Ky., Ind., Mo. and Okla.
56. Carex leptalea Wahl. Fig. 275.
Perennial with creeping scaly rhizomes 0.5-1 mm. thick; culms in tight tufts
along the rhizome, 1-4 dm. long, 0.5-1 mm. thick, erect; sheath venters broadly
hyaline, splitting lengthwise; blades narrower than their sheaths, 0.5-1 mm. broad,
shorter than to occasionally equaling the culms; inflorescence a solitary androgy-
nous spike 5-18 mm. long and 2-3 mm. thick; scales red-dotted, those of the
staminate flowers with edges connate on lower part; bract absent; perigynia com-
press 
