^^^JASW

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NORTH CAROLINA STATE UNIVERSITY LIBRARIES

S02068809 X

CAMBRIDGE BIOLOGICAL SERIES.

General Editor: — Arthur E. Shipley, M.A., F.R.8.

FELLOW AISD TUTUll Ob' CHUIteT'S COLLEGE, CAMBRIDGE.

GRASSES

CAMBRIDGE UNIVERSITY PRESS WAREHOUSE,

C. F. CLAY, Manager.

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ALSO

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[All Ei()hts vi'served.

GRASSES

A HANDBOOK FOE USE IN THE FIELD
AND LABOPtATOEY.

BY

H. MARSHALL WARD, Sc.D., F.R.S.

LATE PROFESSOR OF BOTANY IN THE UNIVERSITY OF CAMBRIDGE,

CAMBRIDGE:
AT THE UNIVERSITY PRESS.

1908

First Edition 1901
Reprinted 1908

PREFACE.

THE following pages have been written in the hope
that they may be used in the field and in the
laboratory with specimens of our ordinary grasses in the
hand. Most of the exercises involved demand exact study
by means of a good hand-lens, a mode of investigation far
too much neglected in modern teaching. The book is not
intended to be a complete manual of grasses, but to be an
account of our common native species, so arranged that
the student may learn how to closely observe and deal
with the distinctive characters of these remarkable plants
when such problems as the botanical analysis of a meadow
or pasture, of hay, of weeds, or of " seed " grasses are
presented, as well as when investigating questions of more
abstract scientific nature.

I have not hesitated, however, to introduce general
statements on the biology and physiological peculiarities
of grasses where such may serve the purpose of interesting
the reader in the wider botanical bearings of the subject,
though several reasons may be urged against extending
this part of the theme in a book intended to be portable,
and of direct practical use to students in the field.

I have pleasure in expressing my thanks to Mr R. H.
Biffen for carefully testing the classification of "seeds"
on pp. 135 — 174, and to him and to Mr Shipley for kindly
looking over the proofs; also to Mr Lewton-Brain, who
has tested the classification of leaf-sections put forward on
pp. 72 — 82, and prepared the drawings for Figs. 21 — 28.

That errors are entirely absent from such a work as
this is perhaps too much to expect : I hope they are
few, and that readers will oblige me with any corrections

VI PREFACE

the}^ may find necessaiy or advantageous for the better
working of the tables.

The list of the chief authorities referred to, which
students who desire to proceed further with the study of
grasses should consult, is given at the end.

I have pleasure in acknowledging my indebtedness to
the following works for illustrations which are inserted by
permission of the several publishers : — Stebler's Forage
Plants (published by Nu-tt & Co.), Nobbe's Handhuch der
Samenkunde (Wiegandt, Hempel and Parey, Berlin), Harz's
Landiviy^thschaftliche Samenkunde (Paul Parey, Berlin),
Strasburger and Noll's Text-Book of Botany (Macmillan &
Co.), Figuier's Vegetable World (Cassell & Co.), Lubbock's
Floivers, Fruits and Seeds (Macmillan & Co.), Kerner's
Natural History of Plants (Blackie & Son), and Oliver's
First Book of Indian Botany (Macmillan & Co.).

It is impossible to avoid the question of variation in
work of this kind, and students will without doubt come
across instances — especially in such genera as Agroiyyrum,
Festuca, Agrostis and Bi^onius — of small variations which
show how impossible it is to fit the facts of living
organisms into the rigid frames of classification. It may
possibly be urged that this invalidates all attempts at
such classifications : the same argument applies to all our
system?, though it is perhaps less disastrous to the best
Natural Systems which attempt to take in large groups
of facts, than to artificial systems selected for special
purposes. Perhaps something useful may be learned by
showing more clearly where and how grasses vary, and
I hope that the application to them of these preliminary
tests may elucidate more facts as we proceed.

' H. M. W.

Cambridgk, April, 1001.

CONTENTS.

CHAPTER I.

PAGE

The Vegetative Organs 1

CHAPTER IT.

The Vegetative Organs {coutiiuwd) .

CHAPTER III.

Grasses Classified according to their Vkgetative

Characters 39

CHAPTER [V.
Anatomy and Histology 02

CHAPTER V.

Grasses Classified according to the Anatomical Charac-
ters of the Leap . 72

Vlll CONTENTS

CHAPTER VI.

PAGE

Grasses in Flower 8;3

CHAPTER VII.

Grasses Grouped according to their Flowers and In-
florescences 99

CHAPTER VIII.

The Fruit and Seed 119

CHAPTER IX.

Classification of Grasses by the "Seeds" (Grains) . 135

Bibliography 175

Index, Glossary and List of Synonyms .... 177

CHAPTEH L

THE VEGETATIVE ORGANS.

That grasses are interesting and important plants is
a fact recognised by botanists all the world over, yet it
would appear that people in general can hardly have
appreciated either their interest or their importance
seeing how few popular works have been published
concerning their structure and properties.

Apart from their almost universal distribution, and
quite apart from the fascinating interest attaching to
those extraordinary tropical giants, the Bamboos, West
Indian Sugar-cane, the huge Reed-grasses of Africa, the
Pampas-grasses of South America ; and from the utilitarian
value of the cereals — Maize, Rice, Wheat and other
corn, &c. — everyone must be struck by the significance
of the enormous .tracts of land covered by grasses in all
parts of the world, the Prairies of North America and
the Savannahs of the South, the Steppes of Russia and
Siberia, and the extensive tracts of meadow and pasture-
land in Europe being but a few examples.

w. 1

2 NUMBERS AND USES [CH.

Although in the actual number of species the Grass
family is by no means the largest in the vegetable
kingdom, for there are far more Composites or Orchids,
the curious sign of success in the struggle for existence
comes out in grasses in that the number of individuals
far transcends those of any other group, and that they
have taken possession of all parts of the earth's surface.
Some species are cosmopolitan — e.g. our common Reed,
Arundo Phragmites; while others — e.g. several of our
native species of Festuca and Poa — are equally common in
both hemispheres. On the whole the Tropics afford most
species and fewest individuals, and the temperate regions
most individuals.

Considering their multifarious uses as fodder and food,
for brewing, weaving, building and a thousand other
purposes, it is perhaps not too much to say that if every
other species of plant were displaced by grasses of all
kinds — as many indeed gradually are — man would still be
able to supply his chief needs from them.

The profound significance of the grass-carpet of the
earth, however, comes out most clearly when we realise
the enormous amounts of energy daily stored up in the
countless myriads of green blades as they fix their carbon.
By decomposing the carbon -dioxide of the air in their
chlorophyll apparatus by the action of. the radiant energy
of the sun, they build up starches and sugars and other
plant-substances, which are then consumed and turned
into flesh by our cattle and sheep and other herbivorous
animals, and so furnish us with food. The whole theory
of agriculture turns on this pivot, and the by no means

l] ORIGIN OF THE WORD GRASS 3

small modicum of truth in such sayings as " All flesh is
grass," and that the man who can make two blades of
grass grow where one grew before deserves well of his
country, obtains a larger significance when it is realised
that the only real gain of wealth is that represented by
the storage of energy from without which comes to us by
the action of green leaves waving in the sunshine.

The true Grasses, comprising the Natural Order
Graminaceae — also written Graminese — are often popularly
confounded with other herbs which possess narrow green
ribbon-like leaves, or even with plants of very different
aspects — e.g. Cotton-grass (Eriophorum) and other Sedges,
and the names Rib-grass (Plantago), Knot-grass (Poly-
gonum), Scorpion-grass {Myosotis) and Sea-grass (Zostera),
as well as the general usage of the word grass to signify
all kinds of leguminous and other hay-plants in agri-
culture, point to the wider use of the word in former
times. This has been explained by the use of the words
gaers, gres, gyrs, and grass in the old herbals to indicate
any kind of small herbage.

In view of the importance of our British grasses in
agriculture, I have here put together some results of
observation and reading in the hope that they may aid
students in recognising easily our ordinary agricultural
and wild grasses. During several years of work in the
fields, principally directed at first to the study of the
parasitic fungi on grasses, and subsequently to that of the
importance of grasses in forestry and agriculture, and to
the variations they exhibit, the need of some guide to
the identification of a grass at any time of the year,

1—2

4 GENERAL CHARACTERISTICS [CH.

whether in flower or not, forced itself on the attention,
and although a botanist naturally turns to a good Flora
when he has the grass in flower, as the best and quickest
way of ascertaining the species, it soon became evident
that much may be done by the study of the leaves and
vegetative parts of most grasses. Indeed some are recog-
nisable at a glance by certain characters well known to
continental observers: in the case of others the matter
is more difficult, and perhaps with a few it is impossible
to be certain of the species from such characters only.

Nevertheless, while the best means for the deter-
mination of species are always in the floral characters so
well worked up in the Floras of Hooker, Bent ham and
others, there is unquestionably much value in the
characters of the vegetative organs also, as the works
of Jessen, Lund, Stebler, Vesque and others abroad, and
Sinclair, Parnell, Sowerby and others in this country
attest.

Almost the only plants confounded with true grasses
by the ordinary observer are the sedges and a few rushes.
Apart from the very different floral structures, there are
two or three easily discoverable marks for distinguishing
all our grasses from other plants (Fig. 1). The first is
their leaves are arranged in two rows, alternately, up the
stems ; and the second that their stems are circular or
flattened in section, or if of some other shape they are
never triangular and solid^ (Figs. 6 and 7). Moreover the
leaves are always of some elongated shaj^e, and without

1 Some foreign grasses {Andropofjon, Pctnicum, &c.) have solid stems,
find in Paamma and some others the lower parts may be solid.

l] SHEATH 5

leaf-stalks\ but pass below into a sheath, which runs some
way down the stem and is nearly always perceptibly split

Fig. 1. A plant of Oat (Avena), an example of a
typical grass, showing tufted habit and loose
paniculate inflorescence (reduced). Figuier.

1 Leaf-stalks occur in tropical Bamboos.

6 DIMENSIONS [CH.

(Figs. 8 — 13). Farther, the stems themselves are usually
terete, and distinctly hollow except at the swollen nodes,
and only branch low down at the surface of the ground or
below it\

All our native grasses are herbaceous, and none of
them attain very large dimensions. In the following lists
I term those small which average about 6 — 18 inches in
the height of the tufts, whereas those over 3 feet high
may be termed large, the tufts being regarded as in
flower. The sizes cannot be given very accurately, and
starved specimens are frequently found dwarfed, but in
most cases these averages are not far wrong for the
species freely growing as ordinarily met with, and in
some cases are useful. I have omitted the rare species
throughout, and in the annexed lists have added the
popular names.

Large Grasses.

(Over 3 feet.)
Miliurii efimurii (Millet-grass).
Digraphis arundinacea (Reed-grass).
Aira coespitosa (Tufted Hair-grass).
Arrhenatherum avenaceum (False Oat).
Elymus arenarius (Lyme-grass).
Bromvs asper (Hairy Brome).
B. giganteus (Tall Brome).
Festuca elatior (Meadow Fescue).

F. sylvatica (Reed Fescue).
Glyceria aquatica (Reed Sweet-grass).

G. Jluitans (Floating Sweet-grass).
Arundo Phragmites (Common Reed).

^ Tropical Bamboos branch in the upper parts and are woody.
Dinochloa and Olyra are climbing grasses.

l] medium and small grasses

Medium Grasses.

(1—3 feet.)
riileum pratense (Timothy).
Avena prateiis^is (Perennial Oat-gras.s).
Anthoxanthuni odoratum (Sweet Veiiial),
Alopecurus agrestis (Slender Foxtail).
A. pratensis (Meadow Foxtail).
Agrostis olha (Fiorin).
Psamma arenaria (Sea Mat-grass).
Avena Jlavescens (Yellow Oat-grass).
Holcus lanatus (Yorkshire Fog).
Hordeimi sylvaticuni (Wood Barley).
H. pratense (Meadow Barley).
Agropyrum repeiu (Couch-grass).

A. caninum (Fibrous Twitch).
Lolkim italicum (Italian Rye-grass).
Brachypodium sylvaticum (Wood False-Brome).

B. pinnatum (Heath False-Brome).
Bromvs erectics (Upright Brome).
B. stenlis (Barren Brome).

B. arvensis (Field Brome).

Festuca ovina (var. rubra, &c.). Sheep's Fescuo.

F. elatior (var. pratensis). Meadow Fescue.

Dactylis glomerata (Cock's-foot).

Cynosurus cristatits (Crested Dog's-tail).

Poa pratensis (Meadow-grass).

P. triviali's (Rough stalked Meadow-grass).

P. nemoraHs (Wood Poa).

Molinia ccendea (Flying Bent).

Melica nutans (Mountain Melick).

M. unijlora (Wood Melick).

Small Grasses.

(6—18 inches.)
PJdeum arenarium (Sand Cat's-tail).
Alopecurus genicidatus (Marsh Foxtail).
Agrostis canina (Brown Bent).
Aira flexuosa (Wavy Hair-grass).

8 ROOTS AND STOLONS [CH.

Aira canescens (Grey Hair-grass).

A. prcecox (Early Hair-grass).

A. caryophyllea (Silvery Hair-grass).

Nardus stncta (Moor Mat-gi-ass).

Hordeum murinum (Wall Barley).

H. maritimum (Sea Barley).

Lolium pereime (Rye-grass).

Z. temulentum (Darnel).

Bromus arvensis (var. mollis). Field Bromc.

Fe.^tuca ovina (Sheep's Fescue).

F. Myurus (Rat's-tail Fescue).

Briza media (Quaking-grass).

Poa maritima (Sea Poa).

P. annua (Annual Meadow-grass).

P. compressa (Flattened Meadow-grass).

P. alpina (Alpine Poa).

P. hidbosa (Bulbous Poa).

Triodia decumbens (Heath-grass).

Kceleria cristata (Crested Koeleria).

The roots of our grasses are almost always thin and
fibrous and are adventitious from the nodes, frequently-
forming radiating crowns round the base and easily pulled
up, and usually broken in the process; but in the case
of a few moor grasses — especially Nardus (Fig. 2) and
Molinia — the roots are so tough and thick {stringy) as to
resist breakage very efficiently. In stoloniferous grasses a
similar difficulty of removal may be caused in a slighter
degree by the underground stems. In a few cases, e.g.
Alopecurus hulhosus (Fig. 3), Poa hidbosa, PJdeum pratense
and P. Boehmeri, Arrhenatheruni avenaceum, and to a
slighter extent in Poa alpina and one or two others, the
lowermost internodes and sheaths of the stems may be
swollen and stored with food-materials, and a sort of Uiber
or bulb results ; this is esj)ecially apt to occur in dry sandy

1]

TU FIED AND BULBOUS GRASSES

Fig. 2. Nardus stricta. Plant
showing tufted habit, and
simple spikate inflores-
cence, with pointed spike-
lets all turned towards one
side (secund) on the ra-
chis (reduced). Note also
the bristle-like (setaceous)
leaves at length reflexed.
Parnell.

Fig. 3. Alopecurus genicidatus, var.
bulbosus. Plant (reduced) showing
habit, bulbous shoots and cylin-
drical spike-like inflorescences
(Foxtail type). Notice the in-
flated sheaths, and the "kneed"
lower parts of the ascending stems.
Parnell.

10 DUKATION OF LIFE [CH.

soils. In old lawns, pastures, &c., the roots of Poa annua
and others may have nodules on them due to the presence
of certain small Nematode worms, Heterodera.

Grasses are annual, biennial, or perennial, and it is
often of importance to know which. The point may usually
be determined by examining the shoots. If all the shoots
have flowering stems in them, and are evidently of the
current year, the grass is an annual; but if any shoots
have leaves only, it is either biennial or perennial : to
determine which is not always easy, but in perennial
grasses there will generally be evident remains of older
leaf-bases and shoots, and if there are distinct under-
ground stolons or creeping rhizomes as well the point
may be considered decided, and the grass is perennial, as
is the case with most of our important species. If all the
shoots are barren, the grass is a biennial in its first year
of growth : if all have flowering stems in them, but show
traces of old leaf-bases of the previous year, then the grass
is a biennial in its second year. The proof of biennial
character is not always easy, however, and a few grasses
may be either annual or biennial, or biennial or perennial,
according to conditions — e.g. species of Hordeum, Bromus,
&c. In the following lists I have given the duration of
the principal grasses, where the character is especially
important.

Annuals.

Pldeum arenannm. Lolmm temulentum.

Aira proecox. Festuca Myurus.

A. mryo'phyllea. Briza minor.

Hordeum muriimm. Poa rigida.

II. maritimum. P. anmia.

ij

ANNUALS AND PERENNIALS

11

Annuals

wliicli nicay become biennial or perennial,

A lopecurus gen icvlatus.

Ifordeum pratensc.

L'diam j^erenne.

L. italicwn (may be perennial),

Bwmus asper (may be perennial).

B. sterilis.

B. arvensis (may be perennial).

Perennials.

Ilolciis lanatus,

H. mollis.

iVardus.

llordevm sylvaticu m,

Agropyrum.

Brachypodium.

Bromus erectvs.

B. giganteiis.

Festuca ovina.

F. elatior.

F. sylvatica.

Dactylis.

Cynosurus crutatus.

Briza media.

Milium.

Anthoxantham,

Digraplds.

Fhleum pratense.

Alopecurus pratensis.

Agrostis alba.

A. canina.

Fsammxi.
Air a ccespitosa.
A. fiexuosa.
A. canescens.
Avena pratensis.
A. flavescens.
Arrhenatherum.
Glyceria aquatica.
G. fluitans.
Poa onaritima.
P. compressa.
P. pratensis.
P. trivialis.
P. nemoralis.
P. alpina.
P. hidbosa.
Molinia,
Melica.
Triodia.
Koeleria.
Arundo.

The rhizome of a perennial grass is continued syra-
podially by means of buds branching from the lowermosb
joints of the flowering shoots, and some importance is
attached to the mode of spreading of these lateral sprout-

12

BRANCHING

[CH.

ing shoots. The buds always arise in the axils of the lower
leaf-sheaths — i.e. they are intra-vaginal. If they remain
intra-vaginal during further growth, the shoots are forced
upwards and only tufts (Fig. 2) are formed, except in so far
as such shoots may fall prostrate on the surface of the
ground later, and throw out roots from their nodes, and
so act as runners or offsets, or put out a few roots &c.
as they ascend through the soil. But in many cases the
buds soon burst through the leaf-sheaths, and develope
as extra-vaginal shoots, and may then run horizontally
as underground stolons. Only creeping grasses of these
latter kinds can rapidly cover large areas ^ : the grasses

Fig. 4. Catahrosa aquatica. Plant showino: the creeping habit, rooting
nodes, and paniculate inflorescence (reduced). Parnell.

^ Except, of course, in cases of virgin ground rapidly occupied by the

seedlings.

l] STOLONIFEROUS GRASSES 13

with intra- vaginal shoots only can only make tufts or
" tussocks." Several peculiarities in the habits of grasses
depend on these facts. The following are the most
important creeping, or stoloniferous species, contrasted
with the much more common tufted and the far rarer
grasses with runners above ground (Fig. 4). Some of
these {Elymus, Psamma, &c.) are of great importance as
sail d- binders.

"With intra-vaginal branches only.

Loliam — slightly stoloniferous.

Festuca elatior— slightly stoloniferous.

Avena flavescens — slightly stoloniferous.

Phleum pratense — no stolons, but may be bulbous.

Dactylis — no stolons.

Festuca ovina— no stolons.

Foa alpina — no stolons.

Cynosunis— wo stolons.

With extra- vaginal shoots.

Arrlienatherum — short stolons, sometimes bulbous.
Holcus ^an«^i«s— creeping.
Alopecurus pixitensis — long stolons.
A n thox'tinthum — slightly stoloniferous.
Agrostis alba (var. stolonifera) — long stolons and runners.
Digra.phis — long stolons.
Foa pratensis — long stolons.
F. tHvialis — runners only.

Festma heterophyUa^ Lam.— a variety of F. ovina with sliglit
stolons.

F. rubra (Linn.) — a variety of F. ovina with long stolons.
Bromus erectiis — no stolons.
B. inermis—low'j' stolons.

14

CREEPING AND TUFTED GRASSES

[CH.

Creeping below ground and truly stolouiferous.

Bromus erectus (slightly).

Festitca ovina (var. riobra, Linn.).

F. elatior (slightly).

Briza (slightly).

Glyceria.

Poa maritima.

Melica.

Arundo.

Agropyrum.

Elynmi^.

Psamma.

Poa pratensis.

P. compressa.

Agrostis alba (var. stolonifera).

Alopecu7'us pratensis. ■

Brachypodium (slightly).

Tufted Grasses.

Miluim. Festuca sylvatica.

Agrostis alba (on downs, &c.). F. J/yurus,

Aira aespitosa. Dactylis.

A. flexuosa. Cynosurus.

A. canescens. Poa rigida,

A. proecox. P. annua.

A. caryophyllea. P. trivialis.

Avena pratensis (slightly creeping). P. nemoralis.

Arrhenatherum. P. alpina.

Nardus (Fig. 2). P. bulbosa.

Hordeum sylvaticum. Molinia.

Loliura. Triodia.

Bromus. Kceleria.
Festuca ovina (except some varieties).

Creeping above ground (with runners).

Holcus lanatus.
Alopecurus geniculates.
Agrostis alba (var. stolonifera),
Hordeum pratense (slightly).
H. murinum (slightly).
Catabrosa (Fig. 4).
Cynodon (Fig. 5).

Hackel has pointed out that a distinction must be drawn
between the true nodes of the culm, and the swellings

1]

SHOOTS AND N(3DES

15

often found at the base of the sheaths themselves over
these : the latter are often conspicuous when the
former are inconspicuous — e.g.
most species of Agrostis, Avena
Festuca, &c.

The nodes are of importance
in the description of a few species
only — e.g. they are usually dark
coloured in certain Foas such as
P. compressa and P. nemoralis'y
they are sharply bent in Alope-
ciirus genicidatus, and may be so
in other species if " layed " by
wind, rank growth, &c.

A point of considerable classi-
ficatory value is the shape of the
transverse section of the shoot,
which is correlated with the mode
of folding up of the young leaf-
blades.

In most grasses the blades are
convolute — i.e. rolled up like the
paper of a cigarette, one edge
over the other — and the section
of the shoot is round (Fig. 7).
In some cases, however, the leaves are conduplicate — i.e.
each half of the lamina is folded flat on the other, the
upper sides being turned face to face inwards, with the
mid-rib as the hinge — and in this case the shoots are more
or less compressed (Fig. 6).

Fig. 5. Cynodon Dactylon.
Plant (reduced) showing
creeping and stolonifer-
ous habit, and peculiar
inflorescence of digitate
spikes. Parnell.

16

SHOOT-SECTIONS

[CH. 1

In these latter cases the transverse section may be
elliptical— e.g. Poa pratensis and P. alpina, Bnza, &c.,

^D

Fig. 6. Daciijlis plomerafn.
Transverse section of a
leaf-shoot ( x 5). A, con-
duplicate leaf-blade. B,
sheath. Stebler.

Fig. 7. Digraphis arundiiuicea. Trans-
verse section of a leaf-shoot ( x 5).
A, sheath. B, convolute leaves.
Compare Fig. 14. Stebler.

or more flattened and linear-oblong — e.g. Glyceria flui-
tans — with the flattened sides straight, or the section is
oval but pointed more or less at each end owing to pro-
jecting keels and leaf-edges, and the form is navicidate —
e.g. Glyceria aquatica, Dactylis (Fig. 6) — or, the sides being
less flattened, more or less rkomboidal as in Poa trivialis.
In Melica the leaves are convolute and the shoot-section
quadrangular.

Flat, and usnall}' sharp-edged shoots.

Dactylis glomerata (Fig. 6).

Poa tnvialis, P. annua, P. pratensis, P. compressa, P. maritima^

and P. alpina.
Glyceria aquatica and G. Jluitans.
Avena pubescens.
LoUum perenne.

CHAPTER 11.

THE VEGETATIVE ORGANS (continued).

The leaves of all our grasses consist of the blade,
which passes directly into the sheath, without any petiole
or leaf-stalk (Fig. 1).

The sheath is usually obviously split, and so rolled
round the internode that one edge overlaps the other,
but in the following grasses the sheath is either quite
entire, or only slit a short way down, the two edges being
fused as it were for the gi-eater part of its length.

Sheath more or less entire.

Ghjceria aqimtica and O. Jluitans.

Melica unijlora and M. nutans.

Dactylis glomerata.

Poa trivialis (Fig. 8), F. pratensis, P. alpina.

Seshria ccerulea.

Bromus (all the sixjcies).

Driza media and B. minor.

In some cases — e.g. Arrhenatherum, Bromus asper, and
Holcus lanatus — the sheath is marked with a more or less
w. 2

18

SHEATH AND LIGULE

[CH.

prominent ridge down its back, due to the continuation of
the heel of the leaf. The sheath may also be glabrous or
hairy, and grooved or not.

A few grasses are so apt to develope characteristic
colours in their sheaths, especially below, that they may
often be recognised in winter by this peculiarity.

Sheaths coloui*ed.

Lolium — all red.
Uolcus — red with purple veins.
Festuca elatior — red.
Cynosums — yellow.
Alopecurus pratensis^ and
A. agrestis — violet-brown, &c.
FestiiAia ovina^ var. riibra — red-

Eig. 8. Poa trlvialis.

A, base of blade.

B, Ugule. C,
sheath. D, culm
( X about 3).

Fig. 9. Alopecurus
pratensis. ^,base
of blade. Bjligule.
C, sheath. Slight-
ly magnified.

Fig. 10. Arena Jiavescens.
Lettering as before
( X 2). Note the split
sheath, the hairs and
ridges. Stebler.

At the junction of the blade with the sheath there is in
most cases a delicate membranous upgrowth of the former,
more or less appressed to the stem, and called the Ligule
(Figs. 8 — 13). Its use is probably to facilitate the shedding

n]

LIGULE AND LAMINA

19

of water which has run down the leaf, and so lessen the
danger of rotting between the sheath and stem : possibly
the shelves and ears commonly met with at the base of
the lamina (Fig. 12) aid in the same process. This ligule
may be long or short, acute or obtuse, toothed or entire, or
it may be reduced to a mere line, or tuft of hairs, or even
be obsolete, and is of considerable value in classification —
e.g. the ligule is obsolete or wanting in Mdlca, Festuca
ovina, F. Mijurus, F. elatior, Koeleria and Panicum.

It is represented by a tuft of hairs in Molinia, Triodia
and Aruiido.

r^ — --

Fig. 11. Loliumperenne.

A, base of lamina,

B, ligule. C, sheath
(x3). Note the low
ribs, and absence of
hairs (glabrous).

Fig. 12. Festuca elatior,
var. jjr«^e;w/5. A,
base of lamina. B,
the extremely short
ligule, with pointed
ears. G, sheath
(x3).

C

Fig. 13. Festuca
ovina. A, base
of lamina. B,
ligularears. C,
sheath (x about
4). Stebler.

Our other ordinary grasses have a more or less well-
developed membranous ligule (Fig. 8).

The leaf-blade is long or short, broad or narrow, but
always of some elongated form such as linear, linear-
lanceolate or linear-acuminate, or subulate, setaceous, &c.,
varying as to the degree of acutenuss of the apex, and
the tapering of the base

20 SHAPES OF LEAVES [CH.

In the following native grasses the foim of the lamina
affords a useful character.

The base tapers to the sheath below — i.e. the leaf is
more or less linear-lanceolate — in Molinia, Brachyj^odium,
Melica, Milium, Koeleria, and the very rare Hierocldoe;
less distinctly so in Bromus asper and species of Hordeum.
The base is rounded in Aimndo. In the following cases
the leaves are setaceous, due to the very narrow blade
remaining permanently folded or inroUed at its edges, and
usually being thickened and hardened also (Figs. 18 and
18). The habitat of these moor- and heath-grasses suggests
that these are no doubt adaptations to prevent excessive
evaporation by the exposure of too large a surface — e.g.
various species of ^?Va, Festuca ovina, F. Myurus and allies,
Nardus, and several other species; whereas, conversely,
the thin fiat leaves of shade-grasses facilitate exposure to
light and transpiration. In Avena pyxttensis and Agrostis
canina some of the leaves are involute and subulate, and
the thickened leaves of Poa maritima also are turned up
at the edges, and are U-shaped in cross-section.

As we shall see later the degree of inrolling of many
grass leaves varies with circumstances.

In most others the blades are either flat (Figs. 8 — 12),
or more or less conduplicate on the mid-rib. The latter
case occurs, for example, in grasses with flattened shoots,
especially at the lower part of the blade — e.g. Lolium
perenne, Dactylis, Glyceria, and some species of Poa, and
the cross-section of the leaf below, just before it enters the
sheath, is V-shaped. In Glyceria the leaf-bases may show
yellow or brownish triangles.

Il] VENATION, TEXTURE, APEX 21

Further characters of the leaves are derived from their
texture, apex, margins, mid-ribs and venation, hairiness, and
especially the presence and characters of the longitudinal
ridges which run along the upper or lower surface in many
cases.

The venation is parallel from base to apex in nearly
ail our grasses, but such is not always the case — e.g. in
the exotic Panicum jilicatani the mid-rib, which enters the
leaf with several vascular bundles, gives off strong and
weak veins below, which first diverge and then run in arches
which converge upwards : this leaf is also remarkable in
being plaited (plicate) in vernation. In Araiido Donax
also the veins, though approximately parallel, do not all
run to the apex of the tapering leaf; the outer ones 'end
above in the margins and are shorter than the mid-rib.

As regards texture^ the leaves of most grasses are thin
and herbaceous ; but in some they are dry and harsh to
the touch. They are thin and dry in Agropyraiii cani-
num, Hordeiim pj^atense, H. murinum, Arena pratensis, &c.,
very hard and leathery {coriaceous) in Psamma, Nardus,
species oi Festuca, Aira, Agropyrum juncewm, Eli/7?ius, &c.
In aquatic grasses like Gli/ceria, the leaf is almost spongy
owing to the large air-chambers developed in the tissues.
These are easily visible with a lens.

The apex is in most cases slender and tapering —
acuminate \ but in some it is merely brought to a point
{acute) as in Catabrosa, Glyceria and several species of
Poa and Avena, &;c., usually flat, but somewhat hooded or
curved up in some Poas. In cases where the leaves are
setaceous or subulate, the apex is like a thin tapering

22 BASE, MARGIN, SURB'ACE [CH.

bristle, and even flatter leaves may be so inrolled at the
tips as to have the apex prolonged into a sharp needle-
like pungent or spinescent point — e.g. Hordeum py^atense,
Avena j^'^^atensis to a slight extent, and pronounced in
Elymus, &c. In SesleHa the apex is rounded with a short,
sharp, prickle-like median projection (nmcronate).

The passage of blade into sheath has already been
described, but the base of the blade may have its margins
projecting as horizontal shelves, like a Byron collar, round
the sides of the throat of the sheath, sometimes tinged
with yellow or pink — e.g. Lolium, Holcus, Bromus inermisy
Hordeum ; the ends of these may project as auricles or
ears — e.g. Festuca elatior, Elymus, Agropyrum, Antho-
ocanthum, Bromus asper, Hordeum, &c. In Festuca ovina
the ears are short, stiff, and erect (Fig. 13).

The margin may be perfectly even, as in most grasses,
or it is more or less scahrid or scaherulous, as in Aira
ccespitosa, Poa maritima, Festuca elatior, Avena pratensis,
Agrostis, Milium, Phleum, Briza, the minute teeth {ser-
rulw) pointing up or down.

The surface may be bright green, or glaucous, harsh,
hairy or glabrous, and is not uncommonly also scahrid, like
a file or emery-paper, and sometimes only when rubbed in
one direction up or down, owing to the minute teeth being
directed all one way. These teeth are developed on the
ridges.

All our ordinary grass leaves are parallel-veined, and
the vascular strands (the veins) can usually be seen on
holding the leaf up to the light. In most cases the tissue
is raised over the veins, as ridges or " ribs," and according

Il] RIDGES ON LEAVES 2;^

to the height of these ridges the thinner parts between
look like deep or shallow furrows (cf Figs. 8 — 16 and
Chapter IV.). If the leaf is held up to the light the
ridges appear dark in proportion to their opacity — i.e.
height or thickness — and the furrows light in proportion
to the thinness of the tissues there. If the contrast is
very great, as in Aira ccespitosa (Fig. 23), the furrows
seem like transparent sharp lines, and when, as in Foa,
which is practically devoid of ridges, the difference of
thickness is small they appear merely as fine stria?.
These characters must be determined on the fresh leaves,
however, because the contraction in drying draws the
ridges closer together and tends to obliterate the lines.
The ridges are almost always evident — Catahrosa, Poa,
and Avena furnishing the chief exceptions — and are nearly
invariably on the upper surface : they are below in Melica,

Fig. 14. Digraphis antndiitacea. Transverse section of mid-rib and half

the leaf ( x about 6).
Fig. 15. Holcns lanatus. Transverse section of leaf-blade ( x 10).
Fig. 16. Cynosnrus cristatus. Transverse section of the leaf-blade

( X 20). Stebler.

24

XEROPHYTES

[CH.

however ; and their relative numbers, heights and breadths,
section — acute, rounded, or flattened — furnish valuable
characters; as also does the coexistence or absence of
hairs, asperities, kc

Fig. 17.

Fig. 18.

Fig. 19.

^/^^^

Fig. 20.

Fig. 17. Transverse section of the leaf of Festuca clatior, var. pratensis

(xl2).
Fig. 18. Ditto of the leaf of F. ovina ( x 1.5).
Fig. 19. Ditto of the leaf of F. ovina, var. rubra (x.35).
Fig. 20. FesUica ovina, var. rubra. Transverse sectioji of the blade of

an upper leaf ( x 35). Stabler.

A very interesting anatomical adaptation is met with
in the leaves of many grasses which grow in dry situations
(xerophytes) such as on sandy sea -shores, exposed mountains
and so forth. When the air is moist, in w^et weather or in
the dews, and the sun's rays not too powerful, the leaf is
spread out with its upper surface flat or nearly so, but
when the scorching sun and dry air or winds prevail,
the leaves fold or roll up, with the upper sides apposed
or overlapping inside the hollow cylinder thus made.

AT r

Il] INFOLDING OF LEAVES 25

In such leaves some of the upper epidermal cells,
either next the mid-rib (Sesleria &c.) or between the other
ribs (Festuca &c.) are large and very thin-walled, full of
sap when distended, and so placed that as they lose water
by evaporation they contract, and so draw together
the two halves of the lamina (Sesleria) or each ribbed
segment (FesUica), thus causing the infolding or in-
rolling (see Chapter IV ). Not only from the structure
and actions of these motor-cells, but also from the fact that
the stomata are on the upper surfaces and thus protected,
and that the lower surfaces which alone are exposed to
the drought are defended by hard and impenetrable
tissues, we must look upon these as adaptations to the
xerophytic conditions.

Leaves prominently ridged.

Eli/Dius. A lopecurus.

Psamma. Glyceria flidtans.

Aira ccespitosa. Kceleria.

Loliuni. Festuca elatior.

Cynosuriis (Fig. 16). Festuca Jlyunis (var. sciuroides).

Agrostis. Melica has ridges on the loioer

surface.

Ridges are less prominent in FJileum pratense, Briza,
Agvopyrum, Triodia, Arrhenatherum avenaceum.

Leaves practically de\oid of ridges.

Poa — all common species.
Glyceria aquatica.
Catah'osa aquatica.
Avena prate nsis.

26 KEELED AND HAIKY GRASSES [CH.

In some grasses the tissue over the mid- rib is con-
siderably raised and strengthened on the dorsal side of the
blade as a " keel."

Keel more or leas promiiient.

Arrhenatherum (sheath keeled).

Poa (all except P. maritima).

Dactylis.

Bromus.

Bromus asper (sheath keeled, often a white line).

Holcus lanatus (slight and decurrent) (Fig. 15).

Digraphis (Fig. 14).

Glyceria.

Most grasses are glabrous, but there are a number in
which hairs are nearly always a prominent feature. It
must be remarked, however, that with grasses, as with
other plants, the character of pubescence is apt to vary
with the situation. In general it may be stated that a
hairy grass tends to become more glabrous in a moist
situation, and more pubescent in a dry one, but the rule
is by no means absolute. In some cases, — e.g. Avena
puhescens, A. flavescens, Agropyrum, the hairs are almost
entirely confined to the crests of the ridges (Figs. 10, 15).
The following is a list of hairy grasses.

Hairy Grasses.

Holcus (Fig. 15). Hordeum.

Molinia ccerulea. Anthoxanthum.

Brachypodium sylvaticum. Avena Jlavescens (Fig. 10).

Agropyrum (variable). A. puhescem.

Bromus asper. THodia.

B. mollis. Kceleria.

To a less extent.
Festuca scmroides (on ribs). Melica.

II J HABITATS Zl

Grasses as a rule are devoid of strong scents' or tastes,
but Anthoa'anthum has a faint but distinct sweet odour,
especially as it dries — it is one of the grasses which give the
scent to new-mown hay — and a bitter flavour, and Milium,
Hierochloe and Holcus are also more or less bitter. Spar-
tina stricta emits a strong unpleasant odour.

The habitat of grasses is of great importance as an aid
to determination. No one would expect to find a sea-shore
grass growing in a beech-forest, or an aquatic grass on a
dry chalk-down; but they are even more true to their
habitats than this, and I append the following lists of
habitats of British grasses as of use in determining
them, though it is not pretended that the limits are
absolute.

In the following list "pasture-grass" (P) means useful
for grazing, and "meadow-grass" (M) one that is especially
valuable for mowing — i.e. for hay. A " weed " (VV) is used
in its agricultural sense for a grass not useful and not
wanted on cultivated land, though often found there.

Meadow- and Pastuue-gr asses.

(P and M) Dactylis glomerata (fields, &c.),

(P and M) Poa trivialis (meadow and pasture).

(W) Bromus m^ensis (cultivated and waste places, meadow and

pasture).
(W) B. sten'lh^ (ruderal).

(P and M) Foa pratensis (meadow and pasture).
(W) Briza media (mecidow and pasture).
(P) Avena pratensis (meadow and pasture, especially hilly).
(P) A. puhescens (var.)— dry.

^ The most marked exceptions are the lemon-scented grasses (especi-
ally Andropogon) of India and Ceylon.

28 SHADE- AND AQUATIC-GRASSES [CH.

(P and M) Lolium perenne (meadow, pasture and waste places).

(P and M) L. italicum (valuable culture grass).

(P) Cynosurus cristatus (downs).

(M and P) Festuca elatior (meadow and moist pasture, banks

and river-sides).
(W) Agrostis alba and A. canina (pasture and waste places,

wet or dry).
(P and M) Alopecwnis pratensis (meadow and pasture).
(W) A. gefiicidatus (moist meadows and marshes).
(P and M) Phleum pratense (meadow and pasture).
(P) Arrhenatherum avenaceum (meadow, hedges and copse).
(P and M) Antlioxanthum odoratum (fields generally).
(W) Hordewn pratense (moist meadow and pasture).
(W) Holcus lanatus and H. mollis (meadow, pasture and waste).
(P and M) Avena Jlavescens (dry meadow and pasture).
(W) Amna fat\ia (corn-weed).
(P) Festuca ovina (light limestone pastures and chalk downs).

Shade-grasses.

Found in woods, copses, &c., under shade.

Melica nnifiora (woods, &c.).

Bromus asper (hedges, thickets, and edges of woods).

B. gigantem (hedges and wo(jds).

Aira ccespitosa (moist shade and damp hedges).

Poa nenwralis (woods, shady places and damp mountain

rocks).
Milium efusuiii (moist woods, &c.).
Agropyruni caninum (woods and shady places).
Hordeum sylmtiaiim (woods and copse).
Brachypodium sylvaticum (woods, hedges and thickets).
Arrhenatherum avenaceum (meadows, hedges and copse).
Festuca sylvatica (mountain woods).

Aquatic and Semi-aquatic Grasses.

Found in wet ditches, ponds, and on marshes, river-banks, &c.

Glyceria Jluitans (wet ditches and slow waters).
G. aquatica (wet ditches and shallow waters).

Il] MOOR-, SEASIDE AND RUDERAL GRASSES 29

Alopecurus geniculatus (moist meadow and marsh lands).
Digrapkis anmdinacea (river-banks, marshes).
Arundo Phragmites (wet ditches, marshes and shallow waters).
Molinia ccerulea (w^et heaths and moors, woods and waste places).
Triodia deacmhens, Aqrostis alba, Catdbrosa and Calamagrvstis.

Moor- and Heath-grasses.

Downs and dry hill-pastures.

Nardiis stricta (moors, heaths and hilly pastures).

Aira Jiexuosa (heaths and hill pastures).

Molinia caendea (wet heathy moors, woods and waste places).

Kceleria ci-istata (dry pasture).

THodia decumhens (dry heathy and hilly pastures).

Festuca ovina (hilly pastures — especially dry and open — rarer

in moist situations).
Agrostis vulgaris and A. camna.

Maritime or Seaside Grasses.

Poa maritima (maritime).

P. distans (sandy pastures and wastes near sea).

Elymus arenarius (coasts).

Psamma arenaria (coasts).

Poa hulhosa (waste places in S.E. of England).

Agropyruni juaceum (coasts).

Hordeum maritimum (S. and E. coast).

Phleum arenarium (coasts).

Ruder A L or Vagabond Grasses.

Waste places, walls, road-sides and dry sandy situations.

Molinia ccerulea (wet, heathy moors, Moods and waste places).

Festuca Myvrus (waste places, walls, road-sides).

F. ovina (hilly pastures and esi)ecially dry, rarely moist

situations).
Aira cari/ophi/Jha (sandy and hilly i)astures).

:30 RAKE AND INTllODUCED SPECIES [CH.

Aira pnicox (sandy and billy pastin-es).

Poa distam (sandy wastes near the sea).

P. compo'essa (dry, barren, waste ground).

P. annua (cultivated and waste lands and fields).

Agropyrum repens (fields and waste places).

Hordeum murinum (waste places and road-sides).

Holcm lanatus (meadow, pasture, and waste lands).

H. mollis (same — rarer).

Alopecitrus agrestis (waste lands and roads in S. of England).

Lolium perenne (meadows, pastin-es and waste places).

L. temidentum (fields and waste places, not common).

Bromus sterilis (on way-sides, &c.).

B. arvensis (cultivated and waste meadows and pastures).

Poa rigida (dry, rocky places).

It is also often useful to know whether a grass is rare
or local, especially for the purpose we have in view, and I
have therefore drawn up the following list of rare, local
or introduced foreign grasses either not noticed at all, or
only referred to incidentally in this work.

In many cases these introduced foreign grasses have
sprung up from seeds brought over in cargoes of hay, wool,
and other products and packing materials, which in part
accounts for their occurrence only near certain sea-ports,
manufacturing tow^ns and so forth. Such plants are
frequently termed ballast plants. Foreign plants are
also introduced in seed, as mixtures or impurities, and
frequently escape from corn-fields &c.

Leerda oryzoides (ditches of Hants., Sussex and Surrey).

Panicuni sanguinale (S. England).

P. verticillatum (fields in S. and E.).

P. glaucwn (rarely introduced).

Hierochloe horealis (Thurso only).

Phleum alpinum (Highlands only).

Il] INDICATOR-PLANTS 31

P. Bcehmeri (Eastern counties, rare).

P. asperum „ „ „

Phalaris canariensis (rare weed).

Alopecurus alpinus (Highlands).

Mihora verna (Anglesea and Channel Islands).

Lagarus ovatus (Suftblk coasts).

Polypogon monspeliejuis (rare, in S. England near sea).

P. littoralis (salt marshes S. England).

Agrostis setacea (dry heaths of S. Wales).

A. Spica-mnti (sandy fields of E. counties).

Gastridium lendigerum (fields and waste places in S. Wales
and Norfolk).

Calamagrostis Epigeios (moist glades &c. in Scotland).

C. lanceolata (moist shades, scattered in England).

C. stricta (bogs, &c., very rare).

Cynodon Bactylon (waste and cultivated lands near sea in Scot-
land).

Spartina stricta (salt marshes S. and E. coast).

Lepturus incurvatus (scattered on shores).

Bromus maximus (Jersey).

B. madritensis (roads and waste, Scotland and Tipperary).
B. inermis (introduced from Hungary).

Lolium italicum (introduced from Lombardy).

Festuca unighimis (Irish and S.E. coast).

Poa procumhens (waste ground near sea).

P. loUacea (sandy sea-shores).

P. laxa (Ben Nevis, &c.).

P. alpina (Highlands and N.).

Catahrosa aqucitica (shallow pools and ditches, scattered).

Finally, a few words may be said on a subject still
in its infancy — that of Indicator-plants. In many cases
certain plants are found so confined to certain classes of
soil, that foresters and agriculturists have claimed to be
able to infer from their presence the presence or absence
of certain chemical or other constituents of soils : on the
contrary we find other plants so universally distributed

32 INDICATOR-PLANTS [CH.

without reference to the quality of the soil, that they are
not indicative. The latter are often termed ruderal or
vagabonds (see p. 29). Without attempting too rigid a
classification of Grasses in this connection — which would
be premature in this early state of our knowledge — the
following remarks are at least generally true.

A few grasses are Indicators of chalk and limestone —
e.g. Briza media, Koeleria cristata, and the exotic sjDecies
Stipa pennata and Melica ciliata.

The following are said to indicate a sufficiency of
potassium salts,

In moister soils.

Difjraphis arundinacea. Arundo Pkragmites.

Phleum prateiue. Molinia ccendea.

Avena pubesceiis. Glyceria flmtans.

In drier soils.

Anthoxanthum odoratum. Dactiflis glomerata.

Alopecurus pratensis. Cynosurus cnstatus.

Agrostis alba. Foa 'pratensis.

Holcus lanatus. I*, trivialis.

Arrhenatherum. P. compressa.

Kcelena cristata. Festuca elatior.

Briza media. Lolium perenne.

Grasses like Bromus arvensis indicate the existence of
clay in the soil.

While the following are indicative of sand,

Aira caryophiiUea. Festuca ovina.

A. pnecox. Bromus sterilis.

A. canescens.

Il] INDICATOR-PLANTS 33

And only if the sandy soil is moist and of better quality,
owing to a certain proportion of humus, the following,

Ant/wxanthum odoratum. Arrhenatherum avenaceum.

Agrostis alba. Arena puhescens.

Bactylis glonierata. Poa pratensis.

That the soil contains considerable quantities of
common salt — sodium chloride — may be inferred if the
foUowinsf grasses occur,

Fsamma arenaria. Hordeum marithmtm.

Elymus arenarius. Agropyrum junce^mi, &c.

The existence of much humus is indicated by such
shade grasses as

Meliea uniflora. Bromus giganteus.

M. nutans. B. asper.

Milium effusum. Bracliy podium sylvaticum.

Whereas soils known as "sour," though containing
much vegetable remains, may be suspected if the following-
grasses abound on them,

Aira ccespitosa. Alopecurus geniculatus.

Nardus stricta. Molinia ccendea ;

especially if sedges and rushes coexist with them.

When cuttings are made in forests, such grasses as
the following are very apt to appear, and may do harm to
young plants,

Festuca ovina and varieties. Holcus mollis.

Agrostis alha. Aira Jleoniosa, &c.

The grasses more especially indicative of particular
classes of forest-soils are chiefly the wood-species (see
w. 3

34 VAGABOND SPECIES [CH.

p. 28), and need not be further specified. In gaps,
borders, and copses — half-shade — we find several common
grasses — e.g.

A nthoxant/iitm odoratum.

Triodia decumhens.

Agi'ostis alba.
Air a Jlex"uosa.

Dactylis glomerata.
Festuca rubra.

Holcus lanatus.

A rrhenatheruTii avenaceum.

Brachypodium pinn a turn.
Hordeum sylvaticum.

ereas

Poa nemoralis,

Jliliiun,

Festuca sylvatica.

Bror/ius asper,

Agropyrum caninmn^
Mdim^

B. giganteus,
Brachypodium sylvaticum,

are more likely to be met with in the deep shade inside
the forest.

On the other hand there are vagabond grasses which
seem to show no signs of preference for one soil over
another — e.g. Poa annua — though in some cases these
ruderal plants indicate the presence of rotting substances,
on ash-heaps and rubbish of various kinds.

With reference to the above, however, the student
must not forget that very complex relations are concerned
in changes of soil, shade, moisture, elevation, &c. and that
although experienced observers can draw conclusions of
some value from the presence of ivmnerotis species and
individuals on a given soil, no one must conclude too
readily that a soil is so and so, from observing solely that
a particular kind of grass will grow there.

An excellent example of what may be done by applying
such knowledge as exists of the habits of grasses, is
afforded by the historic case of the planting up of shifting

ll] ACTION ON SOILS, ETC. 35

sand-dunes with species like Psamnia arenaria, Elyniiis
arenarius, Agropyrum junceum, &c. (together with sand-
binding species of sedges) and so not only fixing the sand,
but preparing it for gradual afforestation with bushes
and eventually trees, and so saving enormous tracts of
land and sums of money, as has been done on the West
coasts of France.

Moreover, the action of ruderal plants — including
grasses — is to completely alter the nature of the poor soil
and gradually fit it for other plants. Coverings of grass
greatly affect the actions of heat and sunshine on the
surface soil, and modify the effects of radiation and
evaporation, to say nothing of the penetrating and other
effects of the roots.

Rhizomes and stolons break up stiff soils ; and every
engineer and forester knows how useful certain grasses
are in keeping the surface-soil from being washed down by
heavy rains on steep hill-sides or embankments.

On the other hand, luxuriant growths of tall grasses
may do harm to young plants, by their action as weeds
and especially as shade-plants ; though foresters can em-
ploy them in the latter capacity, under restrictions, to
shelter young trees from the sun. Again, too much dry
grass near a forest offers dangers from fire ; and it is a
well known fact that certain injurious animals, e.g. mice
and otlier vermin, are favoured by a covering of grass.

Graminacese are for the most part chalk-fleeing plants,
in spite of the fact that certain species can grow in very
thin layers of soil on chalk downs. They must be re-
garded as requiring moderate supplies of humus as a

3—2

yO XEROPHYTES AND HALOPHYTES [CH.

rule, and even sand-loving grasses are not real excep-
tions.

The physiognomy of the grasses has always been
regarded as a striking one, and Humboldt classed it as
one of his 19 types of vegetation. As is well known
they are sociable plants, often covering enormous areas
— prairies, alps, steppes, &c. — with a few species, alone or
densely scattered throughout a mixed herbage. They also
represent characteristically the sun-plants, the erect leaves
exposing their surfaces obliquely to the solar rays, and
being often folded and nearly always narrow.

The dead remains of these sociable grasses are an
important factor in protecting the soil against drought
and in facilitating humification, as well as in covering up
j)lants during long winters or dry seasons, keeping the
ground warmer and moister, and generally lessening the
effect of extremes.

Many Graminacese are pronounced xerophytes, the
epidermis often being developed as a water-storing
tissue, while the erect leaves roll themselves in intense
light, the stomata being situated accordingly. The halo-
phytic strand-plants Psamma areuaria, Elymns arena-
riuSy Agropyram junceum, and other Dune-species, as well
as species o{ Aira, Festuca, Aiithoxanthinn, Stipa, Lygeum,
Aristida, &c. are examples. The heath-grasses — e.g.
Festuca ovina, Nardas stHcta, Molinia cctrulea — also
come under this category.

Many of the strand-plants (halophytes) Agropyruni,
Psamma, Elymus, are covered with waxy bloom, and have
long rhizomes which bind the sand and form new soil, a

ll] HYDllOPHYTES AND MESOPHYTES *i7

property largely taken advantage of in certain forest
operations.

Other grasses, particularly annual species, show their
adaptation to xerophytic habits by forming bulbous store-
houses at the base of the culms — e.g. Phleuni arenarluin.

Some Graminacea3 are hydrophytes, such as Arimdo,
Glyceria, &c., with large intercellular spaces in their tissues;
while many species — e.g. Aira ccespitosa, Agrostis canina,
Molinia cwrulea — grow on wet moor-lands, forming peren-
nial tufts, with or without creeping rhizomes.

The mesophyte grasses are especially characteristic of
what may be termed carpets — a lawn is a good example
on a small scale, though of course we must remember
that here the struggle for existence has been artificially
interfered with more or less. Such carpets consist of the
densely interwoven rootlets and rhizomes forming sod, and
contain much humus from the accumulated debris of former
years. These grass-carpets may be composed of nearly
pure growths of a few species, or of very many different
grasses and other herbage. They are common in Arctic
regions, on Alps, and in temperate climates generally, where
we know them as meadows, haj'-fields, pasture and lawns.

The Bamboos in the wider sense have a physiognomy
of their own, e.g. in India, and may drive out most other
plants and form dense undergrowths or jungle of interlaced
stems and leaves and thorny shoots. Similar growths
occur on the Andes and elsewhere in South America. In
some parts of India and tropical Asia the taller bamboos
form aggregates comparable to dense forests, and such
forests are common on the banks of several large tropical

'SS BAMBOOS [CH. II

rivers. Most of these Bamboos are xeroph} tes. Bamboos
are neither confined to the tropics, nor to warmer regions,
however, for species are known from distinctly cool regions

e.g. South America — or even from near the snow line —

e.g. Chili, the Himalayas, Japan, &:c., and the number of
species known as hardy is increasing annually, as is evident
on examining our larger English gardens.

The permanence and character of extensive grass-
lands, especially prairies, savannahs, and steppes, are much
affected by the periodical firing they are exposed to in
the dry season, and large tracts of country in various parts
of the world would doubtless bear forests or other vege-
tation if not thus fired, while in other cases the herbage
would be differently constituted were firing discontinued.

The following chapter embodies an attempt to classify
our British grasses solely for purposes of identification
wdien not in flower. It is not claimed that the arrange-
ment is the best possible, nor that it is complete, and
I need hardly say that corrections will be gratefully
received.

CHAPTER III.

GRASSES CLASSIFIED ACCORDING TO THEIR
VEGETATIVE CHARACTERS.

I. Sheaths entire except where those of lower

LEAVES ARE BURST BY BRANCHES, &C.

A. Aquatics with the sheaths reticulated, owing to large
air-cavities. Leaves equitant, linear acute, often
floating.

Glycerid flidtans (Br.). Floating sweet grass. Some-
what coarse, but useful pasture in water-meadows and
fens. Sweet-tasting.

Section of sheathed leaves linear oblong ; sheath
striate or furrowed, keeled; leaf ribbed; ligule broad
acute. Leaf-base with a yellow triangle. Smooth.

Glyceria aquatica (Sm.). Reed sweet grass. Especial ly
given to growing in the water-courses and on banks
instead of spreading in the water-meadows, &c. Sweet-
tasting.

Section of sheathed leaves broadly naviculate ; sheath
smooth, no keel : leaf not ribbed, thick and inflated with

40 CLASSIFICATION ACCORDING TO [CH.

lai'ge air-cavities; ligule short. Leaf-base with a brown
triangle. Margins and keel rather rough.

These two species of Glyceria are distinguished by tlieir shoot-
sections and the ridges of the leaves of G. Jluitans : they often occur
in the same ditch.

Tliey cannot readily be confused with others on account of their
aquatic liabit, and the characters given. The only other aquatic or
semi-aquatic species are forms of Catabrosa, Bigrap/ns, Arimdo,
Alopecunis geniculatii.% Molinia caerulea and the rare Calamagrostis.

The ligule and flat shoots with closed sheaths alone suffice to
distinguish it from the round and split sheathed Arundo Phrag-
mites ; and the round shoots of Digraphis, its split sheath and firm
leaves, suffice to distinguish it.

Molinia also has a tuft of hairs instead of a ligule, and a split
sheath, and its habit is diffisrent.

Alopeeurus genicidatus^ with its "kneed" shoots, has a totally
different habit from Glyceria, and its very high ridges and want of
visible air-chambers complete the diagnosis.

Catabrosa is a small creeping aquatic with very flaccid leaves,
quite glabrous and soft. Also sweet-tasting.

B. Not aquatic, and devoid of visible air-chambers in leaf
or sheath. Often perennial, i.e. having stolons or other
branches with no rudiments of flowers in them, and
with relics of old leaf-bases.

(a) Sections of sheathed leaves acute : either two-
edged or four-edged.

(1) Section of sheathed leaves quadrangular. Blades of
leaf thin and dry, sparsely hairy. Sheath quite
entire. Woods and shady places.

Melica uniflora, L. (Wood Melick). Lamina slightly
tapered below, convolute. Ligule obsolete, with a stiff
subulate process on the sheath opposite the blade-
insertion. Kidges below, but not above.

Ill] VEGETATIVE CHARACTERS 41

Melica nutans, L. (Mountain Melick). Ligule longer,

and without the awl-shaped peg. Only in iScotland and

W. of England.

Both are sliade grasses of no agricultural value.
M. unifiora., with its quadrangular shoots and anti-hgular peg,
cannot be confounded with any other grass.

(2) Sections of sheathed leaves more or less acutely two-
edged, owing to the keels of the compressed equitant
leaves.

(i) Shoots broad and fan-like, much compressed, with old
brown leaf-sheaths below, sometimes burst by the
intra-vaginal branches: leaf ridgeless, with prominent
keel. No underground stolons.

Dactylis glomerata, L. (Cock's-foot). An early and
quiclv -growing pasture-grass, which forms much aftermath.
Grows on all soils. Often coarse. Coarse tussocks, and
harsh, with broad thick succulent bluish-green leaves.

Section of sheathed leaves acutely naviculate. Promi-
nent obtuse ligule, torn above. Lamina long, rough, acute,
with white lines if held up, and serrulate edges. No
flanking lines \ No stolons (Fig. 6).

There is a cultivated variety of Dactylis with broad opaque white
sti'ipes down the leaves : these are totally different from the trans-
lucent white stripes seen on holding the wild form, or A ira ccespitosa,
up to the light. Another cultivated "ribbon-grass" — Digraphis —
has round shoots, split sheaths, and a ditterent habit, and the same
ai)plies to its wild form.

Probably the only serious chances of confusion with Dactylis are
between it and Poa pratensis, which also has flattened shoots and
closed sheath ; but in the latter the section of the shoot is elliptical
— not navicidate, — the keel is far less prominent, and the ligule

^ The pale flanking lines seen in many grasses on each side of the
mid-lib are the series of motor-cells referred to on p. 25.

42 CLASSIFICATION ACCORDING TO [CH.

shoi-ter. Moreo\-er P. pratensis is a creeping stoloniferous grass,
less harsh, and with less pointed leaves.

The distance to which the sheath is torn may be from | to \
down. Leaves tend to remain condiiplicate. Margins serrulate with
tcetli extremely short and directed forwards.

(ii) Shoots compressed hut narroio: the section almost
rhomboid with rounded edges.

Foa trivialis, L. (Rough-stalked Meadow-grass). Con-
spicuous in deep rich pastures and orchards, preferring
slight shade and rich soil. Valuable pasture and hay
grass.

Kootstock shortly creeping, branches extra- vaginal and
above ground, shoots rough. Blade narrow, harsh, with an
acute point, thin, shining below, ridgeless, with flanking
lines and keel. Ligule acute, and short or long (Fig. 8).

Sesleria ccerulea, Ard. (Blue Moor-grass), of our
northern limestone hills, has narrow, flat, glaucous blue,
stiff, mucronate leaves, with scabrid apex. Ligule ciliate.

Foa trivialis is most likely to be confounded with other Poas,
especially F. amiv.a and P. pratensis, since they both have thin
leaves and flat shoots ; but P. anniui has a split sheath, less acute
and duller leaves, is annual, and less harsh, and the shoot-section is
flatter at the sides and rounder at the ends.

Poa pratensis, L. is larger and more stoloniferous, with both
extra- and intra-vaginal branches, culms erect and smooth, sheaths
smooth, and the shoot-sections elliptical — not cornered or rhom-
boidal — and with darker green and larger, thicker, 7-veined, more
glossy, and less harsh leaves, with shorter, blunter ligule.

Poa compressa, L. also presents difficulties, but the sheath is
split, and the ligule is shorter than in P. trivialis, the leaves thicker,
find the shoot-sections more Hnear-oblong or elliptical.

(13) Sections of sheathed leaves rounded, circular or
oval, there being no prominent keels.

Ill] VEGETATIVE CHARACTERS 43

(1) Section of sheathed leaves circular or nearly so, the
shoots being only slightly compressed.

* Perennial.

Bromus inermis (Awnless Bromo).

Sections circular, the leaves being convolute, base
shelving. Glabrous sheaths and leaves. Stoloniferous.
Ligule short, truncate, and finely toothed. A forage grass
of the Hungarian steppes. Now being grown in this
country, but of doubtful value here.

Bromus erectus, Huds. (Upright Brome). A weed.

Sections oval and rounded, but leaves equitant. Radical
leaves remain folded and almost subulate, hairy edges. No
stolons. Fields, &c. It is a weed on dry lands, and of
little or no value.

Bromus asper, Murr. (Hairy Brome). In thickets, &c.:
a weed, and useless. Leaves green, long, flat, hanging,
and eared. Sheath with scattered deflexed hairs. Lamina
tapering at the base. Keel a white line, lidges incon-
spicuous: distance between veins 2 — 3 times breadth of
latter. Ligule very short, toothed.

B. giganteus, L. (Tall Brome), also comes here. It is
less common and glabrous. Woods, &c., a useless weed.
** Annual or biennial.

Bromus mollis (B. arvensis, var. mollis, L.), Field
Brome. A too abundant and useless weed in water-
meadows and hay-fields. Softly downy. Blades very thin
and not eared : dry.

Bromus sterilis, L. (Barren Brome). A useless weed.
Rough and downy, but less so than the last. Moist way-
sides, &c.

44 CLASSIFICATION ACCORDING TO [CH.

The Broines are extremely viiriaLle and difficult to determine by
the leaves. The annual species are apt to be biennial or {B. sterilis)
perennial; and some vary much as regards hairiness — e.g. B. mollis
is connected by a series of semi-glal)rous forms to varieties quite
smooth, all grouped by Bentham under B. arvensis.

Bromus asper, being auriculate and a shade-species, runs some
risk of confusion with Hordeum sylvaticum^ but Hordeum has a
split sheath and in B. asper the translucent interspace between the
ridges is 2 — 3 times as broad as in Hordeum sylvaticum.

The other species of Bromus are not eared, and their entire
sheaths at once distinguish them from Hordeum.

Bromus yiganteus has leaves glabrous and very like Festuca
elatior. The red split sheaths of the latter, its sharp ears and
prominent ridges afford the best distinctions ; and B. giganteus has
broader leaves and more evident serrulation or descending bristles
at the basal margins.

(2) Section of sheathed leaves elliptical, owing to the
shoots being compressed. Sheaths often only slightly
split al)ove. No hair on surface of leaves or sheaths.

••• Mai-gim of leaves smooth mid even. Blades without
ridges, a keel and Jiaaking hnes, acute, base rounded.
Lignle of lower leaves very short.

Poa pratensis, L. (Smooth-stalked Meadow-grass).
An early and valuable dry pasture-grass, but though
deep-rooted, it yields thin hay: its chief value is for
"bottom grass" and in lawn mixtures, &c. Leaves stiff and
pointed. Extra-vaginal rooting underground stolons, and
intra- vaginal branches. Shoots smooth. Keel slight : seven
principal veins and smaller ones between. Leaves blunter
and broader than in P. trivialis.

Poa alpina, L. (Alpine Poa). On mountains in the
north. No stolons. 4 — o veins on each side of the median
one.

Ill] VEGETATIVE CHARACTERS 45

Poa pratensis presents similar difficulties to P. trivialis : for
diagnoses see p. 42. It is distinguished from P. nemoralis by its
closed sheath, thicker, blunter and harder leaves, linear-elliptical
shoot-sections, and light coloured nodes, as well as by its habit. All
other Poas have shallow and poorly developed roots.

P. fertilis is a form very like P. nemoralis, with rougher lea\'es
and longer ligule, introduced into cultivation.

** Margins of leaves scahei'idous with descending hairs.
Verif low fiat ridges. Sheath smooth.

Briza media, L. (Quaking Grass). A weed in meadows,
indicating poor soil — e.g. moorlands and chalk — but eaten
by sheep. Tufted and slightly creeping perennial. Ligules
very short, entire.

Briza minor, L. (Lesser Quaking-grass). Annual.
Leaves broader and shorter, and ligules longer. In the
south and rarer.

11. Sheaths split, at least some distance down,

A. Glabrous— i.e. with no obvious hairs ^

ill) Grasses with setaceous or bristle-like leaves ; —
i.e. the lamina of the lower leaves remains
permanently folded instead of opening out tlat.

(1) Ligule obsolete, auricled at the junction of blade and
sheath.

Festuca ovina (Sheep's Fescue). Densely tufted per-
ennial. Leaves hard, glabrous and often glaucous, with
5 — 7 ridges if forcibly unrolled, ears short, stitf and erect.
Branches in permanent sheaths. Chiefly useful as pastures

1 They may have short microscopic asperities, but there are no
distinct long hairs.

4(5 CLASSIFICATION ACCORDIKG TO [CH.

on downs and dry chalk-soils. Several varieties are recog-
nised by agriculturists, as hard, red, various-leafed, fine-
leafed Fescue, &c. (see Figs. 13 and 18).

Festuca Myurus, L. (Rat's-tail Fescue). Annual, longer
auricles, and hair on the ribbed inrolled surface. A road-
side weed.

Festuca ovina presents difficulties with its varieties and with
F. J/i/unis, L. (var. sciuroides, Roth.).

The chief varieties otF. ovina are Hard Fescue {F. duriuscida, L.),
taller and with some of the upper leaves flat, and found in moister
and rich soils : Red Fescue (F. sabulicola, Duf. or F. rubra, L.) more
or less creeping and with led sheaths to the lower leaves, on poor
stony land — F. heterophylla is a form of this on chalky soils, with
flat leaves above : and F. temafolia a very wiry form on sheep-
lands. They all pass into one another, however, and cannot be
distinguished by the leaves (see Figs. 18 — 20).

F. Myurus (var. sciuroides) is ruderal and annual, and has longer
hairs on the ridges of the folded leaves. It has no agricultural value.
(2) Ligule membranous, not auricled.

(a) Brisde-Uke {setaceous) leaves^ very hard and stiff, and
more or less solid.

Nardus stricta, L. (Moor Mat-grass). Roots very tough
and stringy : ligule small, but thick and blunt. Leaves
channelled: upper erect, lower horizontal. Sheath smooth.
Moors and sandy heaths : useless (Figs. 2 and 26).

Aira jiexuosa, L. (Wavy Hair-grass). Roots fibrous.

Leaves short, filiform, terete, solid — the channel hardly

discernible. Ligule short, obtuse. Heaths, &c. Of little

use, even for sheep (Fig. 28).

(/3) Leaves hristle-liJce, but distinctly due to inroUing of
edges.

Aira carijophyllea, L. (Silvery Hair-grass), is scabrid.
A weed, with very slight foliage.

Ill] VEGETATIVE CHARACTERS 47

A. prwcojc, L. (Early Hair-grass). Greener and more
glabrous. Habit more rigid.

A. canescens, L. (Grey Hair-grass). Glaucous or

purplish; rare, on S.E. coasts.

(y) Leaves narroio and more or less involute, and
subulate upwards, but easihj unrolled, and apt to
become Ji^itter as they age.

Avena pratensis, L. (Perennial Oat). Leaves rather
thin, dry, harsh, ridgeless, with flanking lines and a keel^ ;
glaucous, glabrous, but edges scabrous. Usually involute,
but may open out. Ligule long ovate-acute. Dry pastures,
especially on calcareous soil, and of little value.

Poa maritima, Huds. (Sea-grass). Leaves narrow,

rather short, and U-shaped in section. Involute : ridgeless,

with flanking lines, but no keel ; soft and rather thick.

Ligule rather long, obtuse and decurrent. Useless

agriculturally.

For difficulties with other species of Avcna and Poa see pp. 44,
54 and 60.

(h) Grasses with the leaves expanded, more or less

flat.

(1) Blades conspicuously ridged — i.e. the surface is raised

in prominent longitudinal ridges with furrows between.

(i) Leaves rigid and hard, sharp pointed. Sheath and

outer leaf-surface iisually glabrous.

Aira ccuspltosa, L. (Tufted Hair-grass). Forms large
tufts. A coarse weed forming bad tussocks in wet meadows
and pastures : useless for fodder. Leaves flat. Ligule
long, acute. Ridges equal, high and sharp, and scabrid,

1 Very like a Poa when opened out, but the leaves are scabrid at the
sheaths.

4S CLASSIFICATION ACCORDING TO [CH.

with 5—6 white lines between, if viewed by transmitted
light. Wet meadows.

.1. ccespitosa cannot easily be mistaken for any other species.
Alopecurus genwv.hitus is also a moisture-loving grass with strongly
ridged leaves, but the interspax3es are far less translucent and the
whole habit is different.

All the other species oi Aira have involute and setaceous leaves,
and even A. ccespitosa is apt to roll in its leaves in mountain
varieties, but they are easily flattened out, and show the ridges.

PscuinHO arenaria, Beauv. (Sea Mat-grass). This is
one of the most valuable " sand-binders," its long matted
rhizomes holding loose sand together. It is a sea-shore
grass, of no use for fodder. It was formerly much used
for mats and thatching. Leaves concave, long, narrow,
erect, scabrid and glaucous above, and polished below:
pungent. Ridges rounded, alternately high and low.
Sheath long. Ligule very long and bifid.

Elymus arenarius, L. (Sand Lyme-grass). Like
Psamma, this is a "sand-binder" and of no use for
fodder. Leaves concave, and eared at the base of the
blade : ears pointed and tend to cross in front. Ligule
very short and obtuse. Ridges flattened above, not
scabrid. Apex of blade rolled, forming a hard spine.

Psamma cannot easily be mistaken for the much less common
Elyimis, as it is not eared, and the ridges and ligule are very
different.

(ii) Leaves not specially rigid ami hard., and often thin;
glabrorts, or shining heloiv. Ridges less evident.
* Ligvie very short or obsolete ; blade firm but not
hard, glabrovs or nearly so, and shining below.
Sheath often coloured red or yellow at the base.
t Sections of sheathed leaves narrow, oblong, owi^ig
to compression of shoots. Sheath nearly entire.

Ill] VEGETATIVE CHARACTERS 49

Lolium perenne, L. (Perennial Rye-grass). Very valu-
able pasture-grass, especially on clay. Less successful as
hay. Deep rooted tufts. Glossy dark green. Ligule short
(Fig. 11). Sheath red or purplish below. Blade con-
duplicate and keeled, often rounded, collared or eared
at the base ; with rounded ridges and rough above,
shining below. When the ears are well developed their
points often cross one over the other in front of the sheath.

L. italicum, Braun. (Italian Rye-grass), is an earlier and
better variety for hay and sewage farms. Shoot more
rounded in section, and has less marked veins on the more
rolled leaf.

L. temideutum, L. (Common Darnel), is annual and a
weed of corn-fields. Foliage usually rougher.

Lolium perenne presents some difficulties in relation to such
forms as L. italicum, species of Agrostis and Festuca, Alopecwrus
pratensis, Cynosurus and Agropyrum.

Owing to the leaves not being always strictly conduplicate in
the first year, the flat shoots may not sharply mark it off from
L. italicum. Its somewhat looser, almost stoloniferous tufts, and
darker green foliage, less polished below and usually narrower and
harder, have then to be taken into account.

The ridges of Lolium are often like those of Festuca pratensis ;
and the shining lower smface and rather firm leaves and red sheaths,
present other points of confusion. The smooth basal margins of
Lolium, absence of white translucent lines when held up, and the
difterent ligule and ears afford distinctions — the ligule of Festuca
being a mere line, and the ears pointed and projecting, whereas
they may be mere lateral ledges in Lolium.

Cynosurus has the ligule and ears very like those of LoUvm, the
ears being mere ledges ; but the former has yellow sheaths, firmer
and thicker leaves with more evident ridges, and the old plants
usually have the characteristic crested spikes remaining. Cynosurus,
moreover, has the sheath split only a short way down.

w. 4

50 CLASSIFICATION ACCORDING TO [CH.

With regcii'd to Agrostis, there is no colour in the sheath, the
hgule is longer and pointed, and the leaves drier and thinner than in
Zolhim, and harsher on both surfaces. Agrostis has also no ears.

Alopecurus pratensis has much broader and flatter ridges than
Loliuni and a longer hgule, and its sheaths are dark-brown or
black— not red ; but A. agrestis has very similar ridges to Lolium
and may easily be confounded at first.

Agropyrum is sometimes nearly glabrous, and may then be
confused with Lolium by beginners : its low ridges, curled and
pointed ears, obsolete ligule, and thinner, drier, harsher blade, as
well as the stolons, distinguish it.

Lolium temulentum and Hordeum murinum occasionally cause
difficulty, but the latter is always more or less hairy, its blades
thinner and drier, and the ridges less raised.

ft Sections rounded — elliptical or nearly circular.
Sheath distinctly splits at least above.

Cynosurus cristatus, L. (Crested Dog's-tail). Useful
as pasture on dry soils, but only moderately so as hay.
Blade narrow, slightly eared or collared below, tapered
above; firmer than Lolium. Sheath only split a short
way down. Yellow or yellowish-white at the base. Leaves
conduplicate or convolute, short and narrow, the ligule
short : minute ears at base. Usually easily recognised
by the withered culms and persistent pectinate spikes
(Fig. 16).

Festuca elatior, L. (Meadow Fescue). A valuable
meadow and pasture grass, though somewhat coarse.
Several varieties are known. Best on heavy soils. Deep
rooted. Blade flat and broad, conduplicate, sharp-eared
at the base, and there rough at the margin : lower surface
polished. Rich green. Mid-rib flat above, numerous ribs
with white lines bet\veen if held up and examined wdth a
lens. Ligule obsolete (Figs. 12 and 17).

Ill] VEGETATIVE CHARACTERS 51

Arundo Phrag mites, L. (Common Reed). A large
aquatic, reed-like creeping grass, with broad leaves (f to
1 in.), flat, rather rigid, acuminate, glaucous below, hispid
at edges. Sheath smooth, striate, bearded at mouth.
Ligule a mere fringe of hair. (Cf. Digraphis, p. 54.)

Cynosurus is not very liable to confusion ; but it has resem-
blances to Lolium (see p. 49) and to species of Agrostis. The
leaves of Cynosurus are firmer, thicker, less dry, and with a shining
undersurface, and the sheath is only split above, and yellow below ;
whereas Agrostis has relatively thin and dry leaves, rough surfaces
and margin, distinct ridges, and converging margins as the blade
nears the sheath.

Festuca elatior is easily confused with the glabrous Bromes.
For B. giganteus see p. 43.

Bromus erectus is distinguished by the entire sheath, usually
hairy, the want of auricles, and the conduplicate — not convolute —
leaves.

Agrostis has thinner, duller, and drier leaves, and no red sheath.

AJopecurus pratensis has more depressed, flatter and broader
ridges than Festuca, and a longer ligule, and lacks the pointed
ears.

** Ligule whitish, membranous, long, or at least well
developed. Sheaths not coloured or hroivn. Leaves
thin and rough, at least at the base. Ridges twt
'Very prominent, but numerous and distinct.

Agrostis stolonifera, L. (Fiorin). Stolons, with numer-
ous short offsets bursting through the leaf-sheaths. Blade
flat, rough, tapering, with rounded ridges, and convolute in
bud : there are no auricles, but the blade may narrow, and
form ledges, as it runs into the sheath. Sheaths nearly
smooth. Ligule long and pointed, and often toothed at the
margins. The leaves vary in breadth.

This and A. vulgaris, With, with shorter ligules, and,
possibly, A. canina, L. with finer leaves, are varieties of

4—2

52 CLASSIFICATION ACCORDING TO [CH.

A. alha, L. Only the variety A. stolonifera is of moderate
value for pasture, especially on poor soils, as it lasts late
into autumn : the others are weeds, like couch-grass.

Agrostis is full of difficulties for the beginner. The weed-forms
often spring up after wheat has been cut, and count as "twitch,"
like Agropyrum.

All the ordinary forms — A. stolonifera, A. vulgaris, and
A. canina — may be included in A. alba (Linn.). On dry hills a
close tufted grass, with setaceous leaves, and in rich soils creeping
and luxuriant with broad leaves. It is one of the few grasses that
thrive in wet soils.

The chief points in the flat-leafed forms are the thin, dry leaves,
rongh on both sides and on the margins, with distinct raised ridges,
and the base of the leaf narrowing suddenly into its insertion with
the sheath, with no auricle, but with a long membranous ligule.
The sheath not coloured, and the blade convolute.

Again, A. stolonifera has a long, serrated, acute ligule, while
A. vulgaris has a much shorter, entire and truncate one, and
narrower leaves.

Agropyrum is the grass most likely to lead to confusion. Its ears,
lower ridges, very short or obsolete ligule, and pubescence (sometimes
glabrous) distinguish it.

Cynosurvs sometimes gives trouble (see p. 50) with Alopecurus
pratensis : the sheaths, ligule and flattened ridges should suffice for
distinction.

Alopecurus geniculatus is even more like Agrostis, but its ridges
are more prominent and sharp, and its aquatic habit and bent
"knees" distinguish it.

Alopecurus agrestis, in dry corn-fields, has a thickened ligule,
sometimes coloured, and is annual or biennial, but otherwise very
like Agrostis.

Alopecurus pratensis, L. (Meadow Foxtail). Large

grass with stolons ; very early, and much prized as pasture

and hay, but soon dies out on light poor soils. Especially

good for stiff soils. Sheaths long, ridged, brown or nearly

black at the base as they age. Ligule distinct and obtuse.

Ill] VEGETATIVE CHARACTERS 53

entire. Leaves numerous. Blades long, dark green, suc-
culent and scabrous : ridges numerous and flat above, but
distinct (Fig. 9).

A. agrestis^ L. in S. England has shorter leaves, and ridges not
flattened ; it is a troublesome pest of arable land, but does not
usually invade pasture.

A. geniculatus, L. is semi-aquatic, and like the last. It is easily
recognised by its sharply bent "knees," and is of little value (Fig. 3).

Alopecurus shows resemblances to Lolium (see p. 49), Festuca
(see p. 60), and Agrostis (see p. 52). If well grown its ridged
sheath and leaves, the former brown or black at the base, aid in
distinguishing it.

(2) Blades either devoid of ridges or with very incon-
spicuous ones.

* No trace of ridges, and the mid-ribs not prominent^
hut the leaves show median lines flanked by finer ones
when held vp. Blades thin and narrow. Somewhat
heeled,

(i) Shoots compressed.

Poa compressa, L. (Flat-stemmed Meadow-grass).
Leaves rather short, more or less glabrous or glaucous,
and V-shaped at the base ; shoots compressed, and navi-
culate in section. Ligule short and thin. Sheath tends
to be closed below. A creeping perennial on commons
and waste lands, and of little or no value.

Poa annua, L. (Annual Meadow-grass). Small annual.
Compressed shoots, limp. Leaves linear, pale, sub-acute,
thin, often wavy, flat, flaccid, bright green ; dull or slightly
shining and V-shaped in section below. Ligule long,
pointed, whitish and clasping the shoot. It is a harmless
weed, and since it puts out shoots all the year round,
furnishes a certain amount of pasturage.

54 CLASSIFICATION ACCORDING TO [CH.

(ii) Shoots terete or nearly so.

Poa nemoralis, L. (Wood Poa). Leaves and sheaths
smooth. Blade bright green, thin, often glaucous, linear-
narrow, flaccid, acute. Ligule almost obsolete. Section
of shoots round. Of little value.

Poa hulhosa, L. (Bulbous Meadow-grass). Stems
bulbous at the base. Ligule long and acute. Leaves
very narrow and tapering. Sections of shoot round.
Coasts of S. and E.

All the Poas, excejDt the aquatic ones {Glyceria) and P. mariti'ma,
have glabrous ribless blades with the median lines, and slight keel.

P. pratensis, P. alpina and P. tnvialis (Fig, 8) have entire
sheaths (as have Glyceria jVmtans^ G. aquatica and P. maritima)^
but the others have them split some way down.

The leaves of P. pratensis and P. compressa are firmer than the
thin leaves of P. annua, P. trivialis and P. nemoralis.

Sheaths flattened in P. pratensis, P. compressa, P. annua, and
P. trivialis ', but rounded in P. nemoralis. Glyceria aquatica and
G. flvjitans have netted sheaths.

Poa annua is annual, and P, hulhosa has the bulbous base.
P. maritima has involute leaves and no keel, and the rare P. alpina
has short rigid keeled mucronate leaves, with tip often inflexed and
thickened scabrid edges.

The leaves of Avena are apt to appear similar to those of the
Poas at first sight, but the former are hairy, and ridged, dry as well
as thin, and the peculiar median lines of Poa are wanting. Poa
hulhosa has drier leaves than usual, but its leaves are devoid of
ridges.

*■* Ridges can he detected, hut are slight and not distinct.
Margins scabrid, at least at the base.

t Leaves firm, flat, linear, acuminate, not n/xrrowed
below. Glabrous. Ligule membranous.

Digraplm arundihacea, Trin. (Reed-grass). Sheathed
leaves round in section ; blades convolute, tapering above,

Hi] VEGETATIVE CUAKACTEKS 55

flat, firm, long and broad (1 in.) below. Mid-rib and veins
numerous, and prominent below. Stoloniferous : branches
extra- vaginal, often with deep red basal scales. Sheaths
with much overlapping membranous margins, with a
collar-like ledge above. Ligule long and somewhat acute.
Wet ditches, &c., of no value (Figs. 7, 14).

For distinction between Digraphis and Dactylis see p. 41. Poa
pratensis is at once distinguished by its flattened shoots, more
rounded leaf apex and shorter ligule. Arundo Pliragniites is easily
distinguished by the Hgule (see p. 51), and the other aquatic grasses
are quite different (see p. 39).

Phleuni pratense, L. (Timothy-grass). No stolons,
but bulbous on dry ground. Early, and a heavy cropping
hay grass : also excellent pasture ; branches intra-vaginal,
but burst the glabrous sheaths. Old sheaths fibrous.
Leaves short, convolute, with scabrid margins owing to
deflexed teeth : ridges obsolete above, no keel ; broader
and greyer green than Alopecurus. Ligule short on
radical leaves, thin. Pastures. Perennial.

The smooth ligule, deflexed marginal teeth, and no keel
distinguish it from Arrhenatherum.

Phleum arenarium, L. (Sand Phleum). Shoot annual,
with no bulbs. Leaves broad, fiat and glabrous, but rough
at the edges, with descending teeth. Ridges low and flat.
Sheaths smooth : leaves conduplicate. Ligule long. Sandy
coasts, kc. A weed.

Phleum asperum, J acq. and P. Bcehmeri^ Schrad. are rare ruderal
plants, and P. alpinum^ L. is confined to the Scotch Highlands. P.
arenarium is sharply distinct by its conduplicate leaves and habitat.

Alopecurus pratensis has narrower and less grey-green leaves
than Phleum pratense, its ligule is shorter and blunter, its sheath

56 CLASSIFICATION ACCORDING TO [CH.

more grooved and dark below, and the ridges more distinct and flat.
It is relatively well rooted and is stoloniferous.

Arrhenaiherum avenaceum, Beauv. (False Oat-grass).
Loose tufts with short stolons, or bulbous below. Leaves
few, narrow, thin, dry, rough, with very low fiat ribs,
convolute in bud, and practically glabrous. Sheath smooth.
Ligule truncate, hairy on its outer surface. Bitter, and
commonly undervalued by agriculturists, but useful in
mixed pasture, and yields bulky, coarse hay.

There are often a few sparse isolated hairs on the low ribs. The
base enters the sheath with slight and sometimes pinkish ledges.
Eidges hardly observable. Traces of roughness if rubbed downwards.
"White lines, about 5 each side on holding up to the light. The not
very long leaves taper slightly below.

Arrhenatherum is liable to confusion with Holcus^ Anthoooanthum,
Molinia and Aveaa^ but it is typically glabrous, whereas the others
are hairy.

From Holcus it is easily distinguished by the sheaths, ligule and
soft hairs of that genus.

Anthoxanthum differs in its habit, ears, scent, sheath and ligule.

Molinia differs in habit, ligule, sheath, and tough stringy roots,
and the shape of the leaves.

Avena pratensis differs in its narrow leaves, less prominent
ridges, and ligule ; A. Jlavescens in its much broader and coarser
hairy leaves, and the ligule ; and A. pubescens in pubescence and
flat-shoots and ligule.

tt Leaves mry thirty blade tapering below. Keel
prominent, but no ridges aboxe. Ligule long and
torn.

Milium effusum, L. (Spreading Millet-grass). Tufted
perennial. Leaves linear-lanceolate, scabrid above. Sheath
smooth. Bitter tasting. May be slightly hairy. Woods.
It is much liked by birds, but is of no value in agriculture.

Ill] VEGETATIVE CHARACTERS 57

B. Leaves or sheaths, or both, distinctly hairy.

(a) Leaf-blades eared at the base.

(a) Ears sharply pointed. Leaves convolute, and sections
of shoots round. Ligule short and inconspicuous.

Agropyrum 7'epens, Beauv. (Couch-grass). A trouble-
some weed of arable land and gardens, &;c., owing to the
extraordinary vitality of its underground stolons. The
young shoots are readily eaten by stock. Perennial, and
extensively stoloniferous ; bright or glaucous green. Blade
thin, dry, rough edged, hairy and rough above, glabrous
or hairy below. The short ligule fringed. Ears long, or
sometimes short, pointed; often obliquely crossing in
front of the sheath. Ridges inconspicuous. Hairs may
be absent from the sheath, and nearly so from the blade.

The sea-shore varieties are stiflfer and more glaucous, the leaves
more ribbed, involute and pointed — e.g. A. juncemrij Beauv.

Agropyrum caninum, Beauv. (Bearded Wheat-grass).
Tufted weed, not creeping, in woods, &c. Blade thinner
and rougher beneath, but very variable. Properties similar
to those of A . repens.

Agropyrum may be confused with Lolmm (see p. 49) and
Agrostis (see p. 51), but hardly with any other grass, and with
these only because it is liable to be glabrous or nearly so on poor
soil.

Elymus has much more pronounced ridges than the sea-shore
varieties of Agropyrum.

(6) Base of blade with inconspicuous roimded ears. Leaves
convolute. Ligule conspicuous.

Anthoxanthum odoratum, L. (Sweet Vernal-grass).
Compact tuft. Common in pastures and hay, but it only

58 CLASSIFICATION ACCORDING TO [CH.

forms a small proportion of the crop. One of the earliest
grasses, and the principal one, which gives the scent to
new-mown hay : a perfume has been extracted from it.
Its value as fodder is probably overrated. Bitter tasted.
Leaves more or less hairy at margins, especially at throat of
sheath, flat, and slightly ridged. Sheath furrowed, often
pubescent. Ligule long and blunt, with ciliate margins.
Sweet scented when dried. The most shallow rooted of
all meadow-grasses. Leaves often short and few.

Arithoxanthum is sometimes confused with Arrhenatherum (see
p. 56) and Molinia ; the latter differs in its ligule — a tuft of hair —
its stringy roots, tapering leaf-base, less ob\ious ridges, and smooth
sheaths, kc.

Anthoxanthum is deep green and often very luxurious in rich wet
soils — e.g. in Devonshire.

{c) Ears as mere collar-like ledges where the blade joins
the sheath. Sheath usually pubescent or hispid with
reflexed hairs. Kidges inconspicuous. Ligule very
short.

* Perennial, with firmer leaves.

Hordeum sylvaticum, Huds. (Wood Barley). Leaves
flat, thin but firm, rather broad, scaberulous. Sheath
hispid, with reflexed hairs. Blade not tapering below.
Translucent spaces between the veins as broad as the
latter. Ligule *short and blunt. Shady places. Useless.

Hoi'deum pratense, Huds. (Meadow Barley). Tufted, or
bulbous below. Leaves narrower, flat, tending to roll up,
scabrid above and hairy beneath. Sheath narrow, hairy.
Moist meadows, and of some use as pasture in the young
state.

Ill] VEGETATIVE CHARACTERS 69

** Annual, \dth thin dry leaves.

Hordeiim murinum, L. (Wall Barley). Coarse tufts;
leaves small, narrow, hairy or scabrid. Sheaths sparsely
hispid, or very downy, inflated. Roads, &;c. A useless weed.

H. maritwmmj With, is a sea-side form, smaller and more
glaucous. Sheaths hairy.

(/3) Leaf-blades not eared at the base.

* Sheaths of radical leaves veined with red-purple.

Holcus lanatus, L. (Yorkshire Fog). A useless weed,
but very common in pasture and hay ; forming tussocks,
greyish-green, softly hairy (tomentose). Blades with
roundish ridges. Ligule short and obtuse. Sheath some-
what keeled, with trace of collar ledge. It is said to have
a bitter taste (Fig. 15).

Ligule pilose. Tufted hairs along the broad rounded ridges, and
on the lower surface and prominent keel.

The much rarer If. mollis, L. is not so long-haired, except on the
nodes, and is more creeping and slender in habit. It is a " twitch."

The Hordeums present several points of difficulty to beginners.
The dififerences between the species are given above. JI. maritimum
has narrower and thicker leaves than the rest.

Bromes are most likely to be confounded with Hordeums, but
they have entire sheaths and no ears (see p. 43).

For distinctions between H. murinum and Loliuni see p. 49.
H. sylvaticum and Bromus asper (p. 44).

** No conspicuously red-veined sheaths.

t Ligule absent, or a tuft of hairs.

Molinia ccerulea, Moench. (Purple Molinia). Tussocks,
with tough stringy roots. Leaves narrowed below, and
tapering above to a long point, ridges obsolete ; very thin

60 CLASSIFICATION ACCORDING TO [CH.

and dry but fairly stiff, and hairy above, especially at the
base. Ligule absent, or a tuft of hairs. Sheaths smooth.
Moors. Useless as forage, but used locally for brooms.

Molinia is not easily confounded with any others but Anthoxan-
thum (see p. 57), Arrhenatherum (see p. 56) or Brachypodium.

Brae hy podium sylvaticum is distinguished by habitat, its broad
leaves, membranous ligule, fibrous roots, &c.

Koeleria cr^istata, Pers. (Crested Koeleria). Very short,
perennial in dry pastures, pubescent, pale green. Leaves
narrow, tapering below, soon involute, ciliated. Ridges
prominent, alternately high and low. Ligule obsolete,
or a mere jagged yellowish line. Useless.

Triodia decumhens, Beauv. (Decumbent Heath-grass).
Low perennial. Leaves narrow, obtuse, slightly ridged,
tough, at length involute, with long, soft hairs, especially
below and on the edges. Sheath grooved, hairy, especially
at the throat. Ligule a tuft of hairs. Section of shoot
flat ; leaves conduplicate. Of no known use as fodder.

The rare grasses Panicum glahrum, Gaud., P. viride, L. and
P. Crus-galli^ L. introduced in the S.E. counties also come here.

ft Ligule membranous.

Avena flavescens, L. (Yellow Oat-grass). Loose tufted
perennial, pale green, with rounded shoots bursting the
sheaths. Leaves flat, slender, soft, fine-ribbed and hairy,
especially on the low ridges above. Sheath hairy, especially
below, not keeled. Ligule short, obtuse, often truncate,
ciliate. A valuable pasture and meadow-grass, also in
water-meadows. Its roots are abundant, and it will grow
well in calcareous soils (see Fig. 10).

Ill] VEGETATIVE CHARACTEKS 61

Arena puhescens, Huds. (Downy Oat-grass). A variety
of A. pratensis (see p. 47), but less densely tufted, and
the leaves fiat and pubescent, and especially the sheaths
very pubescent. Ligule ovate-acute. Shoots flat. Dry
districts, and a weed.

Avena Jlavescens is not easily confouuded with any other grass if
well grown. All the Poas otherwise like it are glabrous, and without
the ridges. The same applies to A. puhescens.

Arrhenathenom is also glabrous, its leaves narrower, its ridges
much flatter and broader, and its ligule is hairy outside (see p. 56).

Brachypodium sylvaticum, Beauv. (Wood False-brome).
Kather slender, perennial. Leaves flat and devoid of
ridges ; long, very thin and dry, limp, slightly tapering
below, hirsute. Sheath round, hairy. Ligule fairly long,
obtuse, toothed. Copses, &c. Useless.

Brachypodium pinnatum, L. (Heath False-brome), is
a species growing in the open, with narrow, firm, rigid,
erect leaves, hardly hairy; with distinct ridges, and
tending to roll up. Ligule fringed with hair. Open
heaths. Useless.

The only grasses likely to be confounded here are the Bromes,
and they have entire sheaths.

CHAPTER IV.

ANATOMY AND HISTOLOGY.

The principal anatomical features observed in the
leaves of grasses — apart from finer histological details
into which it is not my purpose to enter — concern the
characters of the epidermis and distribution of the
stomata and hairs, the arrangement of the chlorophyll-
tissue, that of the mechanical tissue (sclerenchyma) and
the vascular bundles to which the venation and ribbing
of the leaves are due, and the presence or absence of
those peculiar thin-walled cells (motor-cells) which bring
about the infolding or inrolling of the lamina (see p. 25)
as they lose water, and, finally, the presence or absence
of conspicuous lacunae or air-spaces so characteristic of
aquatic species. Several observers have occupied them-
selves with these matters, and the researches of Schwen-
dener, Duval Jouve, Pfitzer, Pee-Laby, and others have
rendered it possible to group most of our grasses ac-
cording to the microscopic characters of the leaves,
somewhat as I have done in Chapter V.

CH. IV] MOTOR-CELLS 63

Reference has been made to the rolling and folding of
leaves, due to the thin-walled cells on the upper surfaces
capable of varying in turgescence (motor-cells). These

Fig. 21. Transverse section of left-half of leaf of Poa annua ( x about 50)
showing keel below, and two flanking lines of motor-cells (slightly
shaded) above the median vascular bundle of the mid-rib. Hence
the leaf folds. The half lamina has six smaller vascular bundles,
only the stronger one girdered. Eidges practically obsolete and
subtending bands of sclerenchyma slight : hence the leaf-surfaces
are parallel.

are specially adapted epidermal cells found on the upper
surfaces only. In the leaves of Poa compressa, P. annua
(Fig. 21), P. nemoralis, P, alpina, Catabrosay Sesleria, &c.,
a row of these motor-cells, easily distinguished by their
large size, thin walls and clear contents, is found on each
side of the mid-rib; as they dry the leaf folds its two
halves together (conduplicate), and on the re-absorption
of water they flatten the two halves out again. In
Dactylis these flanking rows coalesce into one over the
mid-rib. In other leaves, e.g. Avena pratensis, Festuca
elatior (Figs. 17, 22), Melica, Elymm (Fig. 25), &c., there
are in addition to these two flanking rows, other sets of
motor-cells between the other ribs, and their combined
action causes the halves of the lamina to in roll, usually
one-half inside the other — convolute.

It is easy to observe leaves of such grasses as Festuca
pratensis (Fig. 22), Aira coespitosa (Fig. 23), &c., which

64 EPIDERMIS [CH.

are wide open in the dewy mornings in summer, close
up as the air gets dry and hot ; and any such leaf may
be seen to roll up after plucking and can be reopened
by moistening it.

Fig. 22. Transverse section of left-half of leaf of Festuca elatior, var.
pratensis ( x about 50). The ridges a,re well marked and flattened
above. The vascular bundles of two orders are girdered below, but
only slightly above. There is no keel. There are well marked motor-
cells — not shown in the figure — in each groove.

The epidermis of grasses has been closely investigated
by G"rob, but unfortunately his results concern very few
of our native species. The principal elements are ordinary
elongated cells, with plane or sinuous walls, various kinds
of short cells intercalated between the ends of these, several
forms of papillae, hairs, Szc. and stomata.

The epidermis over the parenchyma of Digraphis
arundinacea consists of rectangular cells with plane walls.

Series or bands of long cells only may alternate with
other series where short cells intervene between the long
ones — e.g. Nardus.

Nardus has some of the bands devoid of stomata,
but abounding in short cells, whereas others (above) have
stomata throughout.

In Nardus stricta, Glyceria fluitans, Sesleria, &c., there
are two kinds of short cells, some siliceous, others cutinized
only.

Nardus has closely appressed small 2-celled hairs bent

IV] EPIDERMIS Go

at right-angles, and some epidermal and parenchyma
cells — especially below the stomata — have solid masses
of silica filling the lumina.

Fig. 23. Part of transverse section of leaf of Aim ccesjntosa ( x about 30).
Eidges very high and acute, each tipped with sclerenchyma, and
containing an isolated vascular bundle — sometimes one or more
small ones also. Motor-cells well developed at the base of each
groove. The bundles are not girdered, but numerous bands of
sclerenchyma almost join into a continuous band below. The
leaf rolls iuwaids.

Short cells occur in Holcus lanatus, Hierochloe
borealis and Dactylis glomerata interspersed between
plane-walled cells. They may be silicified and vary in
shape — square, saddle-shaped, elliptical, irregular, &c. ; or
they may be replaced here and there by asperities — e.g.
Elymus — or in rarer cases by stomata. Grob has at-
tempted the classification of their distribution in different
grasses, but the subject is too complex for treatment here.

The epidermis of many grasses is studded with short
two-celled hairs bent sharply at right-angles ; so that
the pointed or blunt, hollow or solid, apical portion is
appressed to the surface. Grob says that these are absent
from the Hordese, whereas 90 7© o^ tti^ Panicoidese and
many species of all other groups have them. Examples
of the sharply pointed form occur in Nardus, of blunt
ones in Gynodon &c.

In Nai'dus they occur on the leaf surface both
w. 5

66 HAIRS AND ASPERITIES [CH.

between and above the veins, but in Hierochloe &c. they
are confined to the margins.

The following grasses have no hairs of either type :

Agrostis vulgaris, Dactylis glomerata^

Calamagrostis lanceolata, Briza media,

Avena pratemis, Arundo PfiragmiteSy

Arrhenatherum avenaceum, Glyceria Jluitans.

The sharp, hard prickle-hairs which give the pro-
nounced roughness to many leaves of grasses are longer
than the foregoing, and stand off more from the leaf.
They occur both on the surface and at the margins, and
may be isolated — e.g. Avena pratensis, — or mixed with
the short cells — Aira canescens, Elymus arenarius. They
are very abundant on Kceleria cristata.

Leersia oryzoides has asperities at the margin of the
leaf with their points directed upwards on the upper part
of the leaf, downwards on the basal parts, and the direction

Fig. 24. Transverse section of part of leaf of Agropyrum junceum
( X about 40) partly inrolled ; showing unequal ridges. The principal
vascular bundles are girdered below, the sclerenchyma joining into a
strong continuous sheath. Each ridge is tipped with sclerenchyma,
and each groove has motor-cells — not shown in the figure — below.

of such minute marginal asperities often affords a useful
distinctive character — e.g. Phleum, Arrhenatherum. The
marginal asperities in Nardus are siliceous.

IVJ

VASCULAR BUNDLES

67

Bristles — i.e. long, sharp, stiff hairs — are not very
common. They occur on Nardus, Anthoxanthum Puelii,
Panicum, Cynodon.

Papillae occur on the leaves of Glyceria, Nardus,
Leersia, &c.

Poa pratensis has soft hairs on the upper epidermis.

The stomata of Sesleria cceridea are depressed and
six-celled, two guard-cells being overgrown by four ac-
cessory cells, but in most grasses they are of the ordinary
type with two elongated guard-cells only.

As regards the vascular bundles constituting the
venation, they are as is well known parallel from base
to apex in our common grasses, with linear leaves, and

Fig. 25. Transverse section of part of leaf of Elynuis arcimrius, partly
inrolled ( x about 30), showing ridges of unequal height, of which
the higher are flat above. Vascular bundles girdered, the stronger
above and below. Motor- cells in each groove cause the inroUing of
the lamina by their contraction.

are usually of four orders as regards strength. Those of
the first (e.g. mid-rib) and second orders have conspicuous
vessels, but those of the third and fourth orders may be
])i'acrically devoid of vessels, though xylem and phloem

5-2

68 SCLERENCHYMA [CH.

elements are always present. Contrary to the general
assumption, there are frequent though minute transverse
bundles joining the parallel veins.

The rule is that one vascular bundle runs up each
mid-rib or ridge, but exceptions occur — e.g. in Arundo
several bundles run up the mid-rib, and in Aira ccespitosa
(Fig. 23) and others even the strong ribs may have two
or three bundles.

Each vascular bundle has its own sclerenchyma sheath,
and very often the stronger veins are accentuated owing
to the vascular bundle having a girder-like band of
sclerenchyma running conjointly with its sheath and
joining the latter above and below — or below only — to
the epidermis (Figs. 24 and 25). In many cases these
lower girders spread out laterally below — fan-shaped in
section — and nearly join the neighbouring girders.

In other cases the strands of sclerenchymatous sup-
porting tissue do not join the bundles, but run parallel to
them, above or below, as separate strands just beneath the
epidermis.

Finally, these strands may separate from the bundles,
and fuse below into a continuous layer under the epi-
dermis ; this occurs especially in leaves of xeroj)hytes
where the cuticle is well developed — e.g. in varieties of
Festuca ovina (Fig. 18), Aii^a fleoouosa (Fig. 28).

The distribution of the strands of isolated sclerenchyma
affords good characters. While there are none in Mibora,
we find one large strand at the ridge of the keel and one
at each margin, in addition to smaller ones subtending
each vascular bundle, in Avena puhescens, Sesleria, Poa

IV

GIRDERS

69

annua (Fig. 21), P. bulbosa, P. conipressa and Dactylis
glomerata. In Festuca ovina, F. rubra, F, heteropliylla
(Figs. 18, 27) there are groups more or less pronounced at
the keel and margins, or even a continuous band below,
but none above the bundles.

Fig. 26. Transverse section of leaf
of Nardus stricta ( x about 50).
The upper surface is repre-
sented by the four grooves and
five ridges, each of the former
with traces of motor-cells at its
base. The deep shaded por-
tions are sclerenchyma, strong
girders of which join the vas-
cular bundle of each ridge to
the lower surface. This type
is obviously derived from that
in Fig. 19, and may be regarded
as a permanently rolled leaf.

Fig. 27. Transverse section of
leaf of Festuca ovina, var.
duriuscula ( x about 50), the
type of a permanently folded
leaf. Seven ridges and six
intervening grooves are seen :
each of the latter with traces
of motor-cells below. In each
ridge is an isolated vascular
bundle, and a narrow scleren-
chyma baud below.

Many grasses have an isolated band above and below
each primary bundle only — e.g. Panicum, Gynodon — or
above and below each of the other bundles as well —
e.g. Spartina, Arundo, Polypogon, Agrostis alba, Aim
cwspitosa (Fig. 23), Holcus lanatus, Glyceria aqnatica,
G. Jiuitans, Digraphis, Elynius (Fig. 25), Agrupyrum

70 XEROPHYTES, HYDROPHYTES, ETC. [CH.

(Fig. 24), Brachypodium, Nardus (Fig. 26). In Psamma
arenaria the lower bands join into a continuous layer.

In the following there is a band like a girder above
and below each bundle, and contiguous with it, joining
it to the epidermis above and below — Leersia, Phleum
praterise, Calamagrostis Epigeios, Bromus erectus, &c.

Guntz points out that xerophilous grasses are apt to
have upright, narrow (Figs. 26 — 28), grooved or folded
leaves, with strong cuticle, and marked motor-cells when the
leaves open. It is in grasses of this kind, especially such
as inhabit dry sandy districts, that the subulate, solid or
grooved leaves shown in Figures 18, 19 occur — e.g. Festiica
ovina and its varieties, Aira flexuosa, Nardus stricta, &c.
The epidermal cell-walls are sinuous, the stomata pro-
tected— e.g. on the flanks of ribs and in grooves — and
waxy or hairy coverings occur. Colourless water-storing
cells are apt to occur between or around the vascular
bundles, and the chlorophyll-tissues tend to be dense
and well protected inside the leaf: strongly developed
bast-sclerenchyma is also frequent (Fig. 18).

In shade-grasses, on the other hand, and in hygro-
philous species, the leaves are as a rule flat, with thin
epidermal cell-walls, which haye plane sides, free stomata,
and no wax &c. Water-storing tissue (apart from tropical
species) is sparse or absent, and the chlorophyll-tissues
have well aerated lacunar spaces. Bast-sclerenchyma is
in these cases feebly developed.

In the following chapter I have brought together some
of the principal anatomical features, in such form that the
characters can be employed in checking other determina-

IV] HETEROPHYLLY 71

tions of grass leaves. The results, which are based on the
elaborate investigations of Duval Jouve, Schroeter, Pee-
Laby and Grob, as well as on my own observations, are

Fig. 28. Transverse section of subulate leaf of Aira f.exuosa ( x about
50), the upper surface represented by a mere ridge with two flanking
grooves each with but traces of motor-cells below. One large
vascular bundle and four much smaller ones are seen. There are no
girders, but slender bands of sclerenchj'ma at the lower surface
nearly join into a continuous sub-epidermal sheath. This type is
the extreme form of that in Fig. 26.

not complete in all respects, and much more should be
done to extend the theme, but the account given will
serve to show the student how such results may be
employed. It is as yet impossible to decide how far these
characters are constant — they are known to be fairly so in
many cases — but several grasses cannot yet be distin-
guished by them alone.

It should also be added that some grasses develope
two types of leaves (heterophylly), solid or subulate below,
flat or slightly inrolled above — e.g. Festuca heterophylla —
and the following arrangement is intended to apply to the
vegetative lower leaves and not to those on the u^^per
parts of the flowering specimen. Moreover the sections
should be cut from the basal third of the lamina, and not
from the tip of the leaf.

CHAPTER V.

GRASSES CLASSIFIED ACCORDING TO
THE ANATOMICAL CHARACTERS OF THE LEAF.

I. The chlorophyll-tissue, on transverse sections,

IS ARRANGED IN RINGS ROUND THE VASCULAR

BUNDLES. There are motor-cells between the

RIBS, AND the STOMATA ARE SUNK AND OCCUR ON
BOTH FACES.

Gynodon Dactylon. The larger lateral nerves have as
a rule three smaller ones between each pair, hardly pro-
jecting as ribs. Chlorophyll chiefly in a ring round the
vascular bundle. Long hairs on lower surface, a few
papillae above. Motor-cells in each shallow furrow. Short
cells occur between the long epidermal cells over the
bast-region.

The Panicums also come here, and differ according to the
disposition of the sclerenchyma sheaths around the bundles.

CH. V] LEAF-STRUCTURE 73

II. The chlorophyll-tissue is between the vas-
cular BUNDLES, AND NOT CONFINED TO RINGS
SURROUNDING THEM.

A. Conspicuous lacunae between the vascular bundles.
Stomata on both faces. Motor-cells occur.

Lacunae large and rectangular. Motor-cells con-
fined to a flanking line on each side of the
mid-rib.

Glyceria aquatica. Leaves folded and in section
V-shaped, hardly keeled, with sclerenchyma at apex.
Motor-cells each side of the mid-rib only. The large
square or rectangular lacunae bounded by stellate cells.
Papillae on epidermal cells. Vascular bundles midway
between upper and lower surfaces.

Glyceria flidtans. Section V-shaped and keeled, the
roof of each polygonal lacuna arched, hence the " ribs "
on the upper surface are between the vascular bundles.
The latter lie nearer the lower epidermis. The epidermis
has papilhe.

Catahrosa aquatica and Hierochloe also come here, the former
with small lacun?e, the latter with larger ones chiefly towards the
upper sm-face of the leaf.

Digraphis is also apt to have a few air cavities near the mid-rib.

B. Lacuna none, or inconspicuous, the chlorophyll-tissue
filling up between the ribs.

(a) Upper and lower leaf-surfaces parallel, or nearly
so, and much alike, the ridges being very low or
obsolete. Stomata equal or nearly so on both
surfaces.

74 CLASSIFICATION ACCORDING TO [CH.

(1) Motor-cells absent ; vascular bundles feeble and very
few.

Mihora verna. The small leaves are flat, or nearly so,
and have three isolated and very feebly developed bundles,
devoid of girders or sclerenchynia bands.

(2) ]\Iotor-cells present, vascular bundles of various orders,
with sclerenchynia bands or girders.

* Leaf keeled, and folded— not inrolled. Motor-cells
confined to the neighbourhood of the mid-rih. No
hairs.

+ Motor-cells conspicuous and conjoined into a hand
above the mid-rib.

Dactylis glomerata. Keel pronounced, with one large
vascular bundle and a sclerenchynia band occupying its
crest. Motor-cells forming one conjoint band along the
upper course of the mid-rib only. Stomata on both faces,
but no hairs or thick cuticle. Ribs low, and all bundles
have feeble girders. A little sclerenchynia at the margins.
A few pale cells in the chlorophyll-tissue.

tt Motor-cells inconspicuous a7id in tivo flanking lineSy
one on each side of the mid-rib.

Poa trivialis. Keel with sclerenchyma at its apex,
and a small band of the same at the margins. Vascular
bimdles of three orders, isolated, without girders, but
with a small band of sclerenchyma above and below.
Ridges obsolete. Short hook-asperities above. No
thickened cuticle.

Other species of Poa also come here : I cannot distinguish them
by the leaf anatomy ; but P. annua, P. compressa, P. nemoralis and

V] LEAF-STKUCTURE 76

P. prateiisis are devoid of the hooked asperities ; P. nemoralis has a
thicker lamina than the rest, and girders to the secondary bundles,
P, annua agrees in the latter point.

** Leaf not keeled : rolling up. Motor-cells distrihuted
between the ridges.

t Hairs none or rare, or at most a few asperities.

= Veins numerous, 30 — 40 on each half lamina.
Motor-cells very large.

© All vascular bundles uith girders above and

Digraphis arundinacea. No keel. Marginal scleren-
chyma conspicuous. A few asperities below. Leaf thin,
and all the bundles joined to the epidermis above and
below by girders (Fig. 14). Stomata on both surfaces,
fairly large : epidermal cells with plane walls. There may
be a few irregular air cavities, especially near the mid-rib.

©© Only the principal bundles girdered.

Arundo PJuxig mites. Ridges very numerous and low.
No keel. Marginal sclerenchyma strong. Vascular bundles
with sheaths of large colourless cells, a few of the strongest
girdered below, but most have only sclerenchyma bands
above and below. Motor-cells particularly large, between
all the bundles. There are no conspicuous lacunae. Hairs
very rare. Epidermal cells small, with sinuous walls : all
the cell-walls contain silica. Stomata on both faces, sunk,
small and more d fficult to see than in Digraphis, where
the epidermal cells are plane walled, or nearly so.

Arundo Donax is very like A. Phragmites, but has larger bundles
each with a horse-shoe shaped sclerenchymatous mas.s below, and
larger lacuncc.

7tj CLASSIFICATION ACCORDING TO [CH.

= = Vei/is not more than 10 — 20 in each half
lamina.

0 J/ore or less conspicuously/ hairy. The smaller
bundles isolated and devoid of girders.

Bromus sterilis. Girders to the stronger bundles only.
Stitf hairs above and below. Motor-cells poorly developed
between each pair of low ridges. No pronounced cuticle.
A faint sclerenchyma-band at margin, and at apex of low
rounded keel. Stomata on both faces.

Bromus arvensis. Similar to B. sterilis, with stiff
hairs commoner below. Harsh in cutting.

B. giganteus shows no hairs, but I cannot distinguish the Bromes
generally by the leaf anatomy.

Anthoxanthum odoratum. No keel, ridges obsolete,
the stronger bundles only with girders. Motor-cells con-
spicuous between all the ribs. Marginal sclerenchyma,
and that above and below the bundles, poorly developed.
A few coarse hairs both above and below, and stomata on
both faces. Leaf thin and narrow.

Hordeum murinum. Few girdered bundles, and
sclerenchyma at margins poor. Hairs sparse and coarse.

Bromus asper, Brachypodium sylvaticum and Lagurus
also come here.

In all these grasses the epidermal cells are chiefly long, rect-
angular or slightly hexagonal, with thin and plane walls.

©0 Hairs none or very rare on the sections.
Phleum prateme. Low rounded ribs with motor-cells
between. The larger vascular bundles girdered. Stomata
about equal on both faces. No hairs. No keel. Marginal
sclerenchyma scanty.

V] LEAF-STRUCTURE 77

Arrhenathernm avenaceam. Very rare hairs abo\'e :
a few blunt asperities here and there. No keel. Ridges
low. Girders to the primary bundles, but not very strong :
marginal and other sclerenchyma fjiint, as is also the
cuticle. Stomata on both faces. Motor-cells fairly de-
veloped between the ridges.

Briza 7nedia. No keel, and mere traces of marginal
sclerenchyma. Ribs practically obsolete, but well de-
veloped motor-cells in furrows. Principal bundles girdered.
Stomata on both sides. No hairs or thickened cuticle.

Ave7ia fatua, Molinia and Leersia also come here.

(6) Upper and lower leaf-surfaces dissimilar, or at
least not parallel, owing to the conspicuous ridges
and grooves above.

(1) No stomata below.

* Leaves fiat or nearly so, or at least exhibit a con-
spicuous concave upper surface.

© Motor-cells het^veen each pair oj ribs: sderenchyimi
not forming a continuous layer beloiv.

= Ridges at least 5 — 6 times as high as the leaf-
thichaess between.

Aira ccespitosa. Ridges high, 7 — 10 times as high as
the breadth of leaf between, triangular, each with 1 — 3
vascular bundles devoid of girders, with an upper isolated
band of sclerenchyma at the acute tip, and another below
the principal bundle. Also small bands below each group
of motor-cells. Small conical asperities on the ridges and
below. No mid-rib. Stomata on flanks of ridges only,
and few motor-cells between (Fig. 23).

78 CLASSIFICATIOxV ACCOKDING TO [CH.

Each vascular bundle has a sheath, but is isolated.
Sclerenchyma at tips of the ridges dense : smaller bands
below : strong at margins. Lower cuticle strong. Leaf
rolls up.

The flat upper leaves oiFestuca rubra (Fig. 20) and F. hete.rophylla
are somewhat similar in type. They have stiff hairs on the ridges.

= = Ridges not more than 2 — 3 times as high as the
tissue between; each furrow with motor-cells, and
each vasctdar bundle joined to epidermis above
and below by a sclerenchyma girder.

Bracliypodium pinnatum. Smooth. Ridges rounded.

Hairs rare. The strong sclerenchyma girders below almost

continuous laterally. Epidermal cells with sinuous thick

w^alls, and a few tooth-hairs.

Note the differences from B. sylvaticum, p. 76.
Melica nutans, M. unijiora, and Calamagrostis Epigeios also
come here.

® 0 Motor-cells confined to the innermost 2 — 4= furrows.
Sclerenchyma in a continuous band just in&ide the
thick cuticle belou:

Festuca duriuscula. The ridges are only about half
to one-third as high again as the thickness between, and
the motor-cells in four series at the base of the three
innermost ridges. Each ridge has only one isolated
sheathed bundle, without girders. Stomata on the flanks
of the ridges, and few in number. The sclerenchyma forms
a thick band just inside the strong cuticle below. The leaf
is conduplicate, not convolute.

This applies particularly to the more open leaves : the subulate
leaves belong to the next type (see Fig. 27).

Aira canescens and Spartina stncta also come here.

V] LEAF-STRUCTURE 79

Psamma ay^enaria. InroUed. Smooth below and devoid
of keel, with sub-epidermal band of sclerenchyma, and
similar tissue at the margin. Ridges of three sizes, the
largest twice or three times as high as the leaf-tissue
between is thick, all rounded above, and very hairy.
Stomata above only. Motor-cells in each sinus not large.
Vascular bundles isolated, without girders or bands of
sclerenchyma.

Ely tans is very like Psamma, but has a few stomata
below and the sub-epidermal sclerenchyma is not con-
tinuous (see Fig. 25).

** Leaves {subulate) not opening oiit, the upper surface
represented hy a groove or a few ridges above the
angular or ovate solid section.

© Section pentagonal or angular-ovate: sclerenchyma
below in a continuous band.

Aira flexuosa. Upper surface a depression, with one
ridge flanked by two grooves at its base, the depression
extending about one-fifth through the whole thickness
of the nearly solid leaf Vascular bundles about 3 — 5,
isolated, sheathed. Sclerenchyma band extending all
round the lower surface just inside the thick cuticle.
Stomata very few, flanking the ridge ; motor-cells in the
furrows, poorly developed (Fig. 28).

© © Section elliptical or angular-ovate ; sclerenchyma
not always in a continuous band beloiv.

Festuca, ovina. Upper surface a deep fold, with three
ridges and 2 — 4 grooves at its base. Vascular bundles
several, with girders. Motor-cells in four series, in the

80 CLASSIFICATION ACCORDING TO [CIt.

grooves. The lower girders may not fuse laterally into a
continuous band of sclerenchyma below (Fig. 18).

The folded lower leaves of F. rubra and F. keterophylla come here
also. For the flatter leaves of F. duriuscula see p. 78 and compare
Fig. 27.

The epidermal cells in this series have sinuous thickened walls,
and here and there small tooth-like hairs.

Nardus also comes here (see Fig. 26).

(2) There are stomata below, but fewer than on the upper
surface. Motor-cells usually conspicuous between the

* Stronger bundles with girders of sclerenchyma
joining them to the epidermis^ at least below.

© Hairs sparse or none.

Cynosiirus cristatiis. Mid-rib obsolete, except the
strong vascular bundle. Ridges low and rounded, with
2 — 4 flanking stomata, and well developed motor-cells
in furrows. Secondary vascular bundles with strong
girders below, the smaller bundles sheathed only and
isolated. Each ridge with slight sclerenchyma above.
A few stiff short hairs above, and the leaves are con-
volute. Ridges about twice the height of the leaf-thick-
ness between (Fig. 16).

Agropyrmn repens. Mid-rib and margin with strong
sclerenchyma-groups : ridges unequal, low and rounded,
and each vascular bundle girdered. A few pointed hairs
above, and motor-cells in all the grooves. A slight keel,
stomata on both surfaces.

Agropyrmn caninurii. All the bundles have girders.
Slight keel. Marginal sclerenchyma. Few, very short,
hard, hooked asperities above and below. Ridges low.

V] LEAF-STRUCTURE 81

aii<l inotor-cells poorly developed between. Few stomata
on lower surface. Very like A. repens, but the principal
ridges are more prominent below and those nearer the
mid-rib have asperities.

A. jmiceum resembles Psainma, but the ridges are
much lower, and there are a few stomata on the under
surface (Fig. 24).

© 0 Leaf obviously hairy.
f Hairs more especially above.
Avena flavescens is very similar to Cynosurus, but is
evidently hairy, and A. pratensis also comes here.
tt Hairs abundant on both surfaces.
Holcus lanatus. Very hairy above and below, and
at the margins. Slight keel with sclerenchyma band:
sclerenchyma at margin slight. Ridges rounded, about
twice as high as thickness between. Stomata more
abundant above. Cuticle very thin and leaf soft. All
bundles except the mid-rib with girders. Motor-cells
fairly well developed between the ridges (Fig. 15).

Koeleria cristata. A^ery hairy on both surfoces.
Ridges irregular, the largest flat and high, the others
rounded or triangular. Vascular bundles isolated, and
the sclerenchyma reduced to a few cells in a single layer
beneath the epidermis at the apex of each ridge and
below the bundle. Motor-cells well developed in each
furrow. Stomata more numerous above.

** No girders to the vascular bundles.
Lolium jje?'g/i/ie. Ridges numerous and unequal.
Vascular bundles sheathed and isolated — i.e. devoid of
w. 6

b'2

LEAF-STRUCTURE [CH. V

girders : small patches of sclerenchyma at the apex
of each stronger ridge, and on the opposite side below
only. oN'o hairs.

Lolium temulentum is similar but is more apt to be convolute,
whereas L. perenne is more folded.

Alopecarus pratensis. Leaf thin and somewhat like

Phleum, but the ridges somewhat higher and more

rounded, and only the principal bundles girdered below.

Stomata on both faces.

Festiica elatior, Bronius giganteus and most species of Agrostis
come near Lolium. See Figs. 17, 22.

CHAPTER VI.

GKASSES IN FLOWER.

When the flowering shoot of a grass pushes up into
the light and air from the enveloping leaves, it forms a
more or less branched collection of flowers known as the
Inflorescence, and in all our grasses this inflorescence
consists of a principal stalk, haulm or culm, on which
shorter stalks — branched or not — are arranged. The
mode of branching is usually such that the youngest
branches are nearest the top, and the oldest nearest the
bottom. It is evident at once, on comparing the Moor
Mat-grass {Nardus), Vernal-grass (Anthoxanthum), Cock's-
foot (Dactylis), Meadow-grass (Poa) that considerable
differences exist as to the extent of this primary
branching of the inflorescence.

In Nardus (Fig. 2) we find a number of long cylin-
drical-tapering bud-like structures each seated on one
side of the principal stem, and one over the other : in the
Vernal-grass and Cock's-foot we find tufts of such bud-like
structures closely crowded round the upper end of the

6—2

84

INFLORESCENCE

[CH.

13rincipal stalk, the whole forming an elongated tuft of
tufts : in the Poa we find a number of radiating, slender,
long branches sj^ringing from the principal stalk, and each
of these ramifies again, and yet again, until each of the
ultimate hair-like branches bears one of the bud-like
structures. See also Catabrosa (Fig. 4).

Fig. 29. A spikelet of Festuca elatlor, var. pratensis, from which the
glumes and one palea (the outer) have been removed to show the
flower in situ ( x 12). The two lodicules are in front: the inner
palea behind. Strasburger.

The first thing for the student to apprehend is the
nature of the bud-like structures referred to.

Each of these is in itself a small tuft or bud of leaf-

Vl] SPIKELET 85

like organs or scales arranged on a short twig {Rachis,
Rachilla), as it were, and is called a Sjjikelef, and the
true flowers of the grass are contained in the angles
between the scales — the scales being popularly known as
" chaff": technically as Glumes and Palece.

In order to understand the structure of a spikelet the
student should carefully dissect a large one, such as that
of an Oat (Fig. 1). Proceeding from outside, he will find
two large scales, like two boats, fixed below to the stalk
(rachis) one just below the other, and shutting together
as if hinged. These are called the glumes — the inner

Fig. 30. Diagram of a spikelet of a grass as it would appear if the
internodes between each set of organs were elongated, g^ lower and
g" upper glume. P lower and p upper palea of the second oldest
flower F^. /a barren flower represented only by the axis and
paleae. Above it a single palea and the termination of the axis (a)
of the spikelet.

and outer glume respectively — and they enclose the rest
of the spikelet.

Inside them the axis or stalk {rachis) is continued for
a short distance only and on its sides are hinged two

86 STRUCTURE OF FLOWER [CH.

other pairs of more or less boat-shaped scales, smaller and
more delicate than the glumes, and known as the pales
(palece), while a third pair of still smaller pales is fixed to
the end of the axis. In each case one smaller and more
delicate inner palea is hinged just inside its more obvious
outer palea. In the closed condition of the spikelet each
of the three pairs of pales is shut together, and pressed
close to the axis, and the pair of glumes shut in the
whole.

On opening each of the lower pairs of pales we find a
floiuer inside ; but the terminal pair usually contain only
the barren end of the axis. Hence the latter is barren
and the former are fertile.

Each fertile flower is found on careful dissection to
consist of a small swollen Ovary, or young grain, covered
with silky hairs and with a couple of delicate plumes (the
Stigma) at its apex, and three long and slender Stamens ;
while the magnifying glass will show two tiny scales at
the base — the Lodicules. All our ordinary grasses have
their flowers thus constructed — a pair of lodicules, three
dangling stamens and an ovary with a feathery two-
plumed stigma: each such flower is also enclosed in its
pair of pales, and the several pairs of pales of each
spikelet, with their contents, are enclosed in the pair of
glumes (Figs. 29—32).

Returning now to the inflorescence. It is clear that
we have to distinguish between the entire branched total
Inflorescence, and the Spikelets or partial inflorescences
of which it is composed. In Botany it is agreed to call
any inflorescence consisting of a stalk or axis on which

VI

SPIKE AND SPIKELET

87

the flowers are arranged without stalks — i.e. sitting
directly on it — and so that the youngest are above and
the older below, a Spike, and each spikelet is a little spike

Fig. 31. Diagram of a spikelet
of Wheat dissected ( x about
5) showing — from below up-
wards— the two glumes, two
paleae, two lodieules, three
stamens, and the ovary of
the typical grass. Oliver.

Fig. 32. Diagram of a spikelet of
Anthoxanthiwi dissected (x about
8), and showing — from below
upwards — two outer and two
(awned) inner glumes, two paleae,
two stamens, and the ovary.
There are no lodieules. Oliver.

On looking at the total inflorescence of the Nardus we
see that we have a number of spikelets seated on the sides
of an axis : this is then a spike of spikelets, or, shortly, a
Spike^ (Fig. 5). Mibora and Lepturus afford other ex-
amples. In Panicum, Cynodon (Fig. 2) and Spartina we
have groups of such spikes.

1 Strictly speaking a spike is an axis bearing sessile flowers — not
sessile spikelets : in Grasses, however, the conventional abbreviated term
is sanctioned by long usage. The same applies to the panicle, &c.

88 TYPES OF INFLORE'TCENCE [CH.

The Poa inflorescence is, however, different. It con-
sists of a loose branched system of spikelets. Botanists
term such a loosely branching system, where each branch
ends in a flower, a panicle : here then we have a panicle
of spikelets, or, shortly, a Panicle. Aira, Agrostis, Ca-
lamagrostis, Avena, Catabrosa (Fig. 4) and many others
afford farther examples.

In Dactylis we have a condition of affairs between the
two extremes given: the inflorescence is not so close a
spike as Nardus, and not so open a panicle as Poa — it is
rather a spike-like panicle, partaking of the nature of
both. A special type of this (Foxtail) occurring in certain
grasses — e.g. Phleum, Alopecurus, Phalaris and Lagurus,
— is so characteristic as to be worth noting (Fig. 3).

There is also another aspect of these inflorescences
which is not without interest as showing how diagnostic
characters may be obtained from purely external features,
easily observed in the field. We have seen that in
Nardus the spikelets are arranged on one side only of
the rachis, or main axis, so that about three quarters
of the circumference of the latter is bare ; whereas
in Lolium — with which Agropyram and Brachypodiimi
agree in this respect — the spikelets are on opposite
sides, leaving the intervening two quarters, i.e. half its
surface, of the circumference of the axis naked.

In Cynosurus and the simpler forms of Dactylis, we
find the spikelets crowded round about three quarters
of the surface of the rachis, leaving the fourth quarter
naked; and, finally, in Phleum, Alopecurus, Hordewm,
and AnthoxantJnim the spikelets cover the entire surface.

Vl] BARREN AND FERTILE FLOWERS 89

In the iirst (tardus) and third examples {Cynosarus,
Dactylis) where the spikelets are turned to one side, the
inflorescence is said to be secinid.

The next point to notice is that not every grass has
so many as two fertile flowers and one barren one in
its spikelet, as the Oat has. A spikelet may have one
(Phleum), two (Air a) or three (Avena) or more (Poo)
fertile flowers, and no barren ones or several, the number
of flowers being counted by the number of pairs of pales
found inside the pair of glumes. Moreover every flower
is not necessarilj^ fertile (e.g. Arrhenatherum, Holciis) and
several grasses have one or more flowers in each spikelet
containing stamens only — male flowers — while others may
have ovaries only — female flowers. In some exotics the
male and female flowers are on different parts of the same
plant (Maize) or even on different plants {Gynerium),
an arrangement not met with in our grasses. Accordingly,
it is of importance in determining a grass to discover how
many flowers the spikelet contains, and whether any are
male only, or barren, &c., as well as to make out the
character of its inflorescence.

In the following lists I have brought together some of
the chief points with illustrative examples.

Spikelets with only one perfect flower (without
rudimentary ones),

Fsamma, Phleum.

Milium. Hordeuni.

tardus. Agrostis.
Alopecurus,

And species of the rare grasses Calamagrostis, Mihora,

90 SPIKELETS AND [CH.

Lepturas, Spartina, Gynodon, Gastridium, Lagurus, Poly-
pogoHy Leersia.

Spikelets with one perfect flower and one or more male or
rudimentary ones.

Digr aphis. Holcus.

AntJwxanthum. Arrhenatherum.

And the rare genera Hierochloe and Panicum.

Spikelets with at least two perfect flowers.

Molinia. Triodia.

Arundo. Sesleria.

A vena. Kceleria.

Aira (some species). Melica (one species).

Brom us. Briza.

Cynosurus. Poa tHvialis.

Dactylis. Catahrosa.

Spikelets with at least three perfect flowers and usually more.

Elymus. Festuca.

Agropyrum. Poa.

Brad ly podium. Glyceria.
Loliuni.

Inflorescence, a spike of single spikelets.

Agropyrum. Lolium.

Brachypodium. Nardiis.

And varieties of Festuca Myuriis and F. loliacea, &c.

Inflorescence, a spike of pairs or tufts of three or
more spikelets.

Elymus (pairs). Cynosurus (clusters).

Hordeum (threes).

Inflorescence, a cylindrical closely tufted spike-like panicle.

Phleum. Psamma.

A lopecurus. Anthoxanthum.

Vl] INFLORESCENCES 91

Inflorescence, a compact more or less tufted panicle.

Molin la . A ira prcecox'.

Kceleria. A. canescens.

Triodia. Sesleria.
Dactylis.

And rare grasses like Polypogon, Gastridmm, &c.

Inflorescence, a loose plume-like or branched panicle.

Avena. Milium.

Bromus. Agrostis.

Arrhenatheru'in. Melica.

Catahrosa. Holcus.

Aira (except A. pru'cox and Poa (most of the species).

A. canescens). Glyceria.

Arundo. Briza.

Digraphis. Festuca (except F. Myurus).

And the rare HierocMoe.

The Glumes are always present in our grasses, and
rudimentary only in the rare grass Leeisia; but Lolium
and Nardus have only one glume to the spikelet, and
Hierochloe, DigrapMs and Anthoxanthum (Fig. S2) have
four or six. Our other grasses have tivo, but often unequal
in size.

In shape they are usually boat-like, j^ointed or obtuse
{Briza) and frequently with a distinct keel {Anthoxanthum,
Digraphis, Phleum, &c.) or with ridges, green lines (veins)
and other characteristic markings (e.g. BigrapJtis). The
tip may be extended into a stiff long point or awn {Ag-
ropy7nim, Phleum, Nardus) and the keel, ribs, and awn
may have hairs or serrulse on them. The rule is, how-
ever, that the glumes are not awned. In texture the
glumes may be herbaceous and green-brown or purple

92 AWNS [CH.

(e.g. Melica) or membranous or stiff, or scarious (i.e.
browned, as if scorched) at the edges. In Hordeiim
some of the ghimes are so narrow and pointed as to
resemble stiff awns. In Catahrosa the glumes are trun-
cate, as if bitten off at the top.

The Falece are also often more or less boat-shaped, or
flat ovate or oblong scales, usually more delicate than the
glumes and frequently pointed, or (especially the outer
pale) awned at the tip : in some cases, however, the awn
springs from the middle or base of the back of the pale,
and the latter may be bifid at its apex. The pale has
usually a distinct middle nerve. The inner pale is com-
monly the smaller and more delicate of the two, and is
sometimes difficult to see.

Conspicuously awned Grasses.

Avena. Agropy/'um cam num.

Arrhenatheriim (Fig. .33). Lolium temulentum.

Hordeum. Brachypodium sylvaticum.

Brcmus. Festuca Myurus.

And a few rare grasses like Panicum, Folypogon, Lagurus.
Grx^sses with no true awns.

K(xlena.

Poa.

Milium.

Gly'ceria.

DigrapMs.

Catahrosa.

Elymus.

Molinia.

Festuca (except F. Myurus

Melica.

and F. uniglumis).

Psamma.

Briza.

Agrostis alba.

And a few rare forms like Leersia, Hierochloe, &c.

VI]

POLLINATION

93

Grasses with inconspicuous awns, or mere points,

TO SOME OF THE GlUMES OR PaLES.

Arundo.

Phleum.

Alopecurus.

IIolcus.

Kai'dus.

Agro}>i/rum repens.

Lolium perenne.

Brachypodium pinnatum.

Dactylis.

Cynosurus.

Sesleria.

Fig. 33. Arrhenatherum. 1 unopeued and 2 opeu anther (xl2).
3, spikelets open and exposing the stamens and stigmas; 4, the
pollen escaping and being dusted on to the stigmas ( x about o).
Kerncr.

94

MORPHOLOGY OF SPIKELET

[CH.

As regards the flower proper, all our British grasses
except Anthoxanthum (which has two only) have three
stamens ; but many exotic grasses have six stamens, and
a few have a large number — even 40. The stamens have
slender filaments and large versatile anthers, which dangle
from between the paleas when the flowers are mature,
scattering their clouds of fine pollen in the wind (Fig. 83).

All our ordinary grasses except Nardus — where there
is a simple straight hairy style — have
two spreading feathery stigmatic
plumes, which stand out right and
left from between the paleae when
the pollen is flying about on the
wind. (Fig. 38.)

Much interesting speculation has
been expended in attempting to ex-
plain the morphological or theoretical
significance of the parts of the spike-
let of a grass. If we project the
various organs on a flat surface in
the form of a plan, keeping their
relative positions intact, w^e obtain
a diagram such as that shown in
Fig. 34.

The comparison of numerous
cases, and the study of the develop-
ment of the parts on the microscopic
growing point dissected out from
young buds, have suggested that
the inner and outer glumes are bracts, or covering leaves,

Fig. 34. Diagram of a
spikelet of a grass.
The two glumes — g^
outer, (72 inner — em-
brace four flowers, of
which 1 is the lower-
most and d the upper-
most.

Vl] MORPHOLOGY OF AWN 95

at the base of the true spikelet. In like manner the two
paleae are bracteoles which subtend the flower proper.
On this assumption they can be compared with the
corresponding structures in other plants; whereas any
attempt to compare the palese or glumes with the sepals
and petals of ordinary flowers breaks down.

A curious interest attaches to the awns so often
found on the backs of paleae, and especially to those
w^here the (sub-terminal) awn springs from just below
the bifid apex (e.g. Avena, &c.).

Hackel showed by comparison with a rolled leaf
attached to its sheath and ligule (e.g. Psamma) that
such an awn as that of Bromus Alopecurus attached to
its palea stands in the relation of a leaf to its sheath, the
part of the palea above the insertion corresponding to the
ligule, the awn itself to the lamina, and the palea below
its insertion to the sheath. This view is rendered the
more probable by the anatomy of the awn and by the
observations of Schmid, who has shown that the awns of
cereals contain chlorophyll- tissue and a vascular bundle,
and have stomata, and his experiments led him to con-
clude that in the young condition they transpire and
assimilate, and probably even contribute to the nutrition
of the ripening grain. When dry and mature the awns
subserve biological functions of quite another kind, and
as we shall see are of importance in the distribution and
sowing of the grains. (Fig. 42.)

Eeturning to the floral diagram, we see that the two
lodicules, the three stamens and the ovary still remain to

9()

FLORAL DIAGRAMS

[CH.

be explained. Much discussion has been held regarding
the lodicules. Functionally they are said to aid in the
divarication of the palese when the period of anthesis
arrives, and the stamens and stigmatic lobes are to be

Fig. 35. Floral diagram of ordi-
nary gra=s. Each pair of
palesB — i.p. inner and o.p.
outer palea — encloses three
stamens {s), two lodicules (/)
and the ovary, st, stigmatic
plumes, a, axis.

Fig. 3G. Floral diagram of a
Bamboo, showing six stamens,
three inner (/.s.) and three
outer (a.s.), and three lodi-
cules (l) in addition to the
ovary. i.j). inner and o.p.
outer palea. a, axis.

exposed, by swelling and driving the valve-like paleoe
apart. Morphologically they have been explained as
representing the rudimentary perianth, here reduced to
two minute scales, but in some exotic grasses (Bamhusa,
Stipa, &c.) three lodicules, or even more, are present.
(Figs. 35, 36.) On the other hand they may be, and
probably are, scales of the nature of minute bracteoles
and of no significance to the flower itself.

If this is so the flower of the grass is perfectly naked,

Vl] MORPHOLOGY OF THE FLOWER 97

and consists in the typical case of three stamens and one
carpel. The development of the ovary lends no support
to the view that there are two carpels : the stigmatic
plumes are not separate styles. Nor does the fact that
some grasses have six stamens lend support to the idea
that the flower is derived from the trimerous type
so common in Monocotyledons: other numbers may
occur — e.g. as few as two {Anthowanthum, Fig. 32) or
even one only {Uniola, Cinna, &c.) or as many as 20 or 40
in certain other exotic grasses.

Even when three stigmatic plumes are developed, as
in some Bamboos, close investigation does not confirm
the view that the ovary consists of more than one
carpel.

We must therefore regard the flower of the grass as
typically compo.-ed of one carpel and three stamens, with
no perianth whatever. It is subtended by one or more
bracteoles (the lodicules), and enclosed in a pair of
bracteoles one higher than the other (the paleae). The
glumes are bracts of the partial inflorescence — the
spikelet.

That there are some departures from this type in
detail does not invalidate the importance of the fact that
most grasses conform to it.

I now pass to the consideration of a grouping of
our ordinary grasses according to their floral arrange-
ments.

The student should distinctly understand that the
following notes are intended to serve as an introduction
to the floral characters of our grasses, and not to replace

98 USE OF THE FLORA [CH. VI

the study of the Flora. I have dealt with this section of
the subject less in detail, because our best Floras give so
much information that it seemed undesirable to do more
than attempt to guide the reader in the recognition of
the genera and principal species by means of external
features easily observed by anyone with a little care.
The detailed and critical examination of species, varieties
and rare forms should always be done with reference to a
complete Flora.

CHAPTEE VIL

GRASSES GROUPED ACCORDING TO THEIR
FLOWERS AND INFLORESCENCES.

I. Grasses with only one perfect flower in

THE SPIKELET.

(1) Inflorescence spikate^

A. Inflorescence a spike of simple spikelets.
Nardus stricta, L. A tough wiry tufted moor-grass,

with setaceous leaves, secund spikelets with a single
rudimentary glume, and a stiff simple hairy style.
(Fig. 2.)

The much rarer Mihora vcrna about three inches or so high, and
LepturiLS^ both with flat leaves, also come here.

Certain superficial resemblances in the habit or inflorescence in
Festuca Myurus and rare forms like Spartina^ may occasionally
cause hesitation until the spikelets are examined.

B. Spike with sessile or sub-sessile tufts of three or
more spikelets.

{a) A spike of tufted awned spikelets, in triplets

at each notch of the rachis, and one or two

of each triplet barren.

Hordeum.

^ See note, p. 87.

100 CLASSIFICATION ACCORDIXG TO [CH.

No other genus of our grasses is like Horchwn. The purely
superlicial resemblances in the inflorescences of Polypogon, Lagurus,
and Cynosurus echinatus — all extremely rare species — disappear at
once on examination.

In Broirms erectus the equally superficial resemblance is due to
the stifi'awns: the spikelet has six to twelve flowers and is stalked.
It should also be noted that Hordeum sylvatmcm occasionally
has a rudimentary second flower in the lateral spikelets (see note
p. 105).

(a) A shade-grass with the central spikelet only
imperfect ; staminate, or rudimentary, or en-
tirely wanting.

H. sylvaticuni, Huds.

(/3) The central spikelet is the perfect one, the
two lateral barren. Growing in open land.

(i) A perennial meadoiu-grass. All the
glumes scahrid and bristle-like.

H. pratense, Huds.

(ii) Annuals with some of the glumes at
least, lanceolate or hroad below.

* Ruderal plant, ivith cylindrical spikes, long
aims ; glumes of the central flower dilated
below.

H. murinum, With.

** Mantime plant, more or less glaucous, vnth
short ovoid spikes: glumes of the central floiver
bristle-like.

H. maritimum, With.

(b) Spike cylindrical, of sessile or nearly sessile
awned spikelets, densely crowded round the
axis, the whole resembling a fox's brush or
cat's tail.

VIl] FLORAL CHARACTERS 101

Species of Lagurus^ Polypogon, Fhalaris (not truly awned),
Panicum (with bristles between the spikelets), and Gastridium are
other British grasses approaching this type of inflorescence : they
are all rare or very local.

Seslena has an ovoid spike, but the spikelets are two-flowered
and not truly awned.

Kceleria may present resemblances, but the spikelets are very
difi'erent in detail (see p. 109).

(i) Aiuns inserted into the bach of the single

palea, and hair-like. Glumes connate beloiu,

keeled. Only one palea.

Alopecurus.

* Annual corn-weed, with a long and slender
spike, pointed above. Glumes almost glabrous,
and connate to the middle.

A. agrestis, L.

** Perennials, with shorter and stouter spikes,
rounded above. Olumes connate at the base
only, and obviously hairy on the keel.

t Procumbent and kneed at the nodes below.
Spike 1 — 2 inches long. In marshy places.

A. geniculatus, L.

tt A meadow-grass, with erect stems, and spikes
2 — 3 inches or more and stouter.

A. pratensis, L.

The rare A. alpimis, Sm. with short ovoid spikes, about one inch
long, only occurs in the Highlands.

(ii) Awns, when present, merely the stiff, pointed
termination of the keel. Glumes free below.
Palece two.

102 CLASSIFICATION ACCORDING TO [CH.

* A glaucous sJiore plant vnth long creeping stolons
{sand-hinder). Inflorescence harsh, 5 — 6 inches
long. Glumes tapering, simply acute.

Psamma arenaria, Beauv.
Elymus, a miicli rarer sand-binder of similar habit, may lead
to confusion imtil the 3 — 4 flowered spikelets and different arrange-
ment are observed. (See p. 108.)

Agropyrum repens (var. junceum) is similar in habit and station,
but its spikes and spikelets are very different (see p. 107).
Phleum arenanum is much smaller (see below).

** Erect. Inflorescence rarely longer than three
inches. Spikelets flat: ghtmes keeled, the keel
suddenly produced into a sharp stiff awn or
mucronate point. Palece two.

Phleum.

t Tall perennial meadow-grass. Awn bnstle-
like, almost as long as the nearly glabrous
glume: spike long, cylindrical.

F, pratense, L.

If Small, compact annual shore plant, uith the

glumes acute only and the keel ciliate above.

Inflorescence not more than 1 — IJ inch long.

P. arenarium, L.

The rare P. Boehmeri, Schrad. has the glumes merely tapering
to a sharp point ; and the rare P. alpinum, L. has a much shorter
spike and glumes ciliate on the keels.

The rare P. asperwn, Jacq. has broad, shortly mucronate glumes
and a longer and more slender spike.

(2) Inflorescence a panicle— i.e. tufts or spreading^

stalked groups of spikelets are arranged on

the main axis.

A. Inflorescence compact and irregular; a spike of

tufts (spike-like panicle). Glumes four, the inner

pair awned : paleae minute. Stamens two only.

Anthoxantkum odoratum, L.

VIl] FLOHAL CHARACTERS 103

The four glumes and two stamens distinguish this grass at once.
Other grasses with occasionally tuft-like inflorescences — e.g. species
of Agrostis, Gastridium, Aira, Dactylis, Cynosurus, Poa, Triodia,
Kceleria — are distinguished at once by having three stamens
(Bromtis occasionally has but two), only two glumes, several
flowered spikelets, &c.

B. Inflorescence a distinctly branched panicle, more
or less loose and spreading.

(a) Tall reed -like perennials, growing in water
or in marshes, with plume-like inflorescences,
and silky hairs at the base of the palea?.
Glumes with a keel and point, but not awned.

(i) Spikelets purplish : outer palea with a slender
dorsal awn : basal hairs longer than the palese.
Leaves narrow. Not common.

Calamagrostis Epigeios, Roth.

(ii) Spikelets greenish. No awns : basal hairs
much shorter than the palese. Leaves broad.
Common.

Digr aphis arundinacea, Trin.

A variety of Digraphis with white stripes in the leaves is grown
in gardens. Other aquatic reed-like grasses are Arundo and Glyceria
aquatica : both have several flowers in the s})ikelet.

The rare Calamagrostis lanceolata^ Roth., C. stricta, Nutt. and
0. strigosa, Hartm. also come here.

(b) Slender grasses, not reed-like, with delicate
loosely spreading panicles of small spikelets.

(i) A tall, slender shade-grass, in woods. Palese
very smooth and glistening. Spikelets few,
distant and turgid, awnless.

Milium effusinn, L.

104 CLASSIFICATION ACCORDING TO [CH.

Melica uniflora, also a wood-grass, has the spikelets two-
flowered, though the upper one may be a mere rudiment, and
much fewer, on a flexuous nodding axis. The much rarer M. nutans
has two perfect flowers in the spikelet (see p. 105).

(ii) Grasses of open situations, with numerous

small pointed spikelets. Inner palea minute

or absent.

Agrostis.

The genus most likely to give trouble here is Aira^ which
though normally with two flowers in the spikelet, occasionally has
but one. As regards the common species of similar habit, &c.,
Aira has bristle-like leaves and Agrostis flat ones.

Again, Agrostis alba has no protruding awn, as in the spikelets
of Aira. For Aira ccespitosa and other details, see p. 117.

* Awnless, or at most a short bristle not

equalling the palea. Leaves flat and

short.

A. alba, L.

An exceedingly variable plant. The variety A. stolonifera has a
less spreading panicle, and broader leaves with a long serrated
and pointed ligule : the variety A. vulgaris has a spreading loose
panicle, narrower leaves, and a short truncated ligule. There is,
however, much difficulty in distinguishing the intermediate forms
on mo\mtain -pastures, &c.

** Distinctly aiuned. Leaves narrower, the
loiuer ones inr oiled and almost setaceous.

A. canina, L.

The rarer A. setacea, Curt, with subulate leaves and A. Spica-
venti, L. with long awns also come here.

The lax spreading type of panicle characteristic of Aira and
Agrostis, &c., described above, occiu-s in species of Averia, Bromus,
Briza, Foa and Catabrosa, but the basal silky hairs and twisted
awns (Avena), long sub-terminal bristle-awns (Bromus), habit

VIl] FLORAL CHARACTERS 105

{Catabrosa), and the presence of two, three, or more flowers in
the considerably larger spikelets of all, easily distinguish them.

The rare grasses Leersia, with two glumes and no palese, and
Gastndiiim, with curiously bullate bases to the glumes, also come
into this group with one-flowered spikelets, but their characters
must be studied with the flora. The same remark applies to species
of Panicmn^ Cynodon, Spartina and other ahens, occasionally
met with.

11. Grasses with at least two flowers — of which

ONE may be imperfect — IN THE SPIKELET.

A. Only one perfect flower, the other staminate
only or altogether rudimentary. Inflorescence
a loose or racemous panicle.

In Hordeum sylvaticum the two lateral spikelets occasionally
conform to this heading (see p. 100), and the same is said to be
the case sometimes in Aira (see p. 104). The rudiments are
extremely minute, however, and hardly sufiice to justify the removal
of these grasses to this group.

In one or two species of Aira the panicle may be somewhat
contracted and tuft-like.

The very rare Hierochloe has one perfect flower, and two lower
staminate ones in each spikelet.

(a) A shade-grass found in woods. Awnless. One
flower perfect, the other (upper) reduced to a
small stalked knob. Inflorescence racemous.

Melica uniflora, L.

The much rarer M. nutans has two perfect flowers and a similar
rudiment (see note, p. 104).

(6) Grasses of open situations, spikelets with awns.
The reduced flower staminate.

106 CLASSIFICATION ACCORDING TO [CH.

* Upper flower perfect, lower staminate only. Tall oat-
like meadow-grass, with a bent and twisted dorsal awn
to the outer palea of the lower flower : silky hairs at
the base of palese.

Arrhenatherum avenaceiim, Beau v.

The grasses most like this are species of Avena and Aira.
The former have two or more perfect flowers, and the only
broad-leafed Aira — A. ccespitosa, see p. 117— is easily distinguished
by its leaves and its very small spikelets and short simple awns.

** Upper flower staminate: lower perfect. Small hairy
grasses, with red-veined basal leaf-sheaths and short

simple awns.

Holcus.

t Urect, evenly hairy, glumes blunt, men not pro-
truding. Common.

H. Icmatus, L.

ft More or less procumbent, hairs chiefly at the nodes.
Glumes pointed. Aivns simple and exserted. Rarer.

H. mollis, L.

B. Each spikelet with at least two perfect flowers,

often more

(1) Inflorescence spikate, the main axis bearing sessile
or sub- sessile spikelets, each containing three or
more flowers.

(a) Spike simple ^ axis stout and notched, each

notch having one spikelet closely sessile in it.

(i) Spikelets distichous, the flat side of each — i.e. the
edges of the glumes — being next the axis (rachis).

Agrop3n:um.

* A weed luith creeping stolons, and no aiuns
or mere points to the glumes.

A. repens, Beauv.
1 See note, p. 87.

VIl] FLORAL CHARACTERS 107

The variety A. juvceum found as a sand-binder on soa-coasts
is glaucous, stiffer, with sharply pointed leaves, and blunt glumes.
For other sand-binders see note, p. 102.

** Not creeping. Awns long and prominent.

A. caninum, Beau v.
(ii) The rounded backs of the glumes are next the rachis.

* Spikelets flat and closely sessile in the notches

of the rachis,

Lolium.

t Aivnless or nearly so. Perennial.

L. perenne, L.

ft With conspicuous atoms. Annual, not common.

L. temulentum, L.

There are several cultivated varieties of L. perenne : L. temu-
lentum is notoriously poisonous (see note, p. 168). The lowermost
glume of each spikelet is often alone developed or conspicuous, and
looks like a bract in the axis of which the spikelet sits.

** Spikelets elongated and hardly flattened, and
not quite sessile, especially the lower: racliis
scarcely notched, the spikelets iviih their sides
(edges of glumes) next the axis.

Brachypodium.

t A shade-grass with long, conspicuous awns to the
more or less drooping sp)ikelets. Common.

B. sylvaticum, Beauv.

tt Growing in the open. Spikelets stouter, stiffer
and more erect, with short awns. Not common.

B. pinnatum, L.

Brachypodium may easily be confounded with Bromus, but the
spikelets are nearly sessile : their shape and the absence of con-
spicuous notches distinguish this genus from Agropyrum. Lolium

iOa CLASSIFICATION ACCORDING TO [CH.

has a conspicuously notched rachis and the spikelets arranged in the
other plane.

Foa loliacea, Huds., an uncommon sea-shore weed, may also be
placed here; as also Festuca elatior, var. loUacea, Curt, and some
forms of Bromus arvensis, var. mollis, L.

No other British grasses resemble Brachypodimn : any superficial
likeness remarked in species of Hordewn^ Festuca, &c. disappears
at once on examination.

(6) Spike compound — i.e. with clusters of two or
more sessile or sub-sessile spikelets arranged
along the rachis.
(i) Spike elongated, fertile spikelets with 3 — 5 flowers.

* Pasture-grass with wiry rachis, on which the spikelets
are secund and sessile in clusters: in each cluster a
comb-like group of barren glumes subtends one of
fertile spikelets.

Cynosurus cristatus, L.

The rare (7. echinatus has the pectinate groups of barren glumes
even more ^jrominent.

** Stout glaucous sand-binder with pairs of

sessile in the notches of the rachis, and all fertile.
Spike cylindrical. Not common.

Elymus arenarius, L.

For other sand-binders see p. 102. The only grass likely to be
confounded is Agropyrwm, in which the spikelets are not paired.
Lolivm,^ Brachypodium, &c. are easily distinguished.

(ii) Spike short and ovoid: spikelets sub-sessile and im-
bricate, in clusters. Bluish.

Sesleria ccerulea, Ard.

Not easily mistaken for any other grass. As some of the
spikelets are shortly stalked, the inflorescence is strictly pani-
culate, but the fact is not obvious. The glume-like bract at
the base of the spike, and the general appearance suggest resem-

yn] FLORAL CHARACTERS 109

blances to certain moor-sedges at first sight. The only other
grasses with similarly shaped spikes are sijecies of Alopecurus,
Phleum, and the rare Lagurus, Polypogon, Phalaris, Panicum^ all
with very difierent spikelets and easily distinguished.

(2) Inflorescence a panicle or raceme— i.e. the spikelets
on evident stalks, simple or branched, from the
main axis.

It does not follow that every spikelet is distinctly stalked, and
cases occur where the stalks are very short and stiff : when this
happens to the stalks arising from the main axis, and the latter is
elongated, the type of the spike is closely approached, and the
inflorescence resembles that of Br achy podium^ Lolium^ &c. In
some depauperated varieties of Poa, Festuca, &c., an actual spike
results (see note, p. Ill) : the number of flowers in the spikelet is
important.

(a) Panicle short, contracted and tuft-like, owing to

the shortness and stiffness of most of the stalks

and their tendency to remain erect, at least until

anthesis. Glumes keeled and ending in a point.

(i) Panicle luith a few branches, at first erect,

ending in tuft-like secund clusters. Spikelets

harsh , ivith 3 — 5 floivers. Coarse meadow-grass.

Dactylis glomerata, L.

Not easily confounded with any other grass if attention is
paid to the folded coarse leaves, the tufted perennial habit, and
the harsh inflorescence, the glumes on the spikelets being stiflfly
hairy on the keel.

(ii) Panicle contracted, more or less ovoid or cylin-
droid, hut most of the spikelets stalked, and not
aggregated into dense clusters, spikelets silvery,
containing 2 — ^flowers.

Koeleria cristata, Pers.

110 CLASSIFICATIOX ACCORDING TO [CH.

Any resemblances to forms of Aira are at once nullified by the
absence of true awns in Koeleria. Festuca and Poa have more
numerous flowers in the spikelet. Anthoxanthiim has only one flower,
with two stamens, in the spikelets. Phleum and Alopecurus present
icsemblances, but see pp. 101 and 102.

ih) Panicle elongated and lax — i.e. all or most of the
spikelets on distinct slender stalks, longer than
themselves.

(i) Panicle close: the spikelets on distinct and

even long stalks, hut the latter erect and keeping

the spikelets near the main axis.

In some cases the stalks from the main axis bear only one
spikelet each and the type of inflorescence is that of a raceme ;
usually, however, one or more of the lowermost stalks branch and
disclose the panicle.

* Panicle with few simple branches, racemous,
each spikelet large and containing about four
flowers, palea three-toothed at the apex. A
small heath-grass, with hairs at the ligule.

Triodia decumhenSy Beauv.

The inflorescence may have some resemblance to Melica (see
p 105), but the four-flowered spikelet, ligule, habitat and stature
distinguish it at once.

** Panicle with divided branches, which are more
or less erect.
+ Spikelets awnless.
© Spikelets small, purplish, with two or at
most three florets ; the upper on a stalk.
Coarse moor-grass.

Molinia ccerulea, Moench.
© © Spikelets with six or more florets.

VIl] FLORAL CHARACTERS 111

:|: Tall aquatic grass with long, lax, narroio
panicle and spikelets, somewhat nodding,
and ivith 8 — 20 flowers in each.

Olyceria fluitans, Br.

The only similar grass is Olyceria aquatica, Sm. which dififers in
its more reed-like habit, open panicle, and fewer flowers.

XX Small land-plants not more than a foot
high, with short, stiff, someiohat crowded
panicles, and spikdets containing 6 — 8
floxoers.

== MaHtime perennial \oith creeping stolons,
and about afoot high: panicle somewhat
open below.

Poa rnaritima, Huds.

E3 = Inland plant ivith secund panicle, about
six inches high.

P. rigida, L.

The rare P. procumbens. Curt, and P. bidbosa, L. also come
here, as well as starved forms of P. compressa, L. Some forms of
Festiica elatior, var. pratensis, Huds. growing in dry situations may
give trouble, and will have to be examined with the flora. See also
note, p. 109.

ft Spikelets awned.

0 Aivns bristle-like and terminal on the paleoe:
flowers albout sijn in each spikelet. Leaves
setaceous. Panicle secund.

= Awns long and bristle-like. An annual
weed.

Festuca Myurus, L.

= = Axons very short, or merely the drawn out
points of the palece. Perennial.

F. ovina.

The rare F. uniglumis, Soland., and some other varieties may
also come here.

112 CLASSIFICATION ACCORDING TO [CH.

Some forms of F. ovina are viviparous (see p. 134), and several
varieties have to be distinguished.

0 0 Awns hair-like and dorsal on the paleoe. Flowers
two in each spikelet. Annual, six inches or less
in height.

Aira prcecox, L.

The rare A. canescens, L. also comes here: its awn is jointed and
with a minute tuft of hairs about the middle.

(ii) Panicle lax and open, the fine hair-like branches
spreading widely during florescetice, or even
pendent or drooping.
* Spikelets aAvnless.

+ A small aquatic grass with prostrate habit and
two-flowered spikelets with broad truncate
glumes and paleae.

Catahrosa aquatica, Beau v. (Fig. 4).

The two-flowered spikelets distinguish it at once from Glyceria
aquatica, to say nothing of its softer and smoother texture and
small stature. Poa trivialis may have two flow^ers, but it is an
erect meadow-grass, with keeled and pointed glumes and palese.
Aira and Agrostis are awned, or differ entirely in habit.

t+ Spikelets with at least three or four, but usually
more flowers.

© A perennial field-grass ivith few large,
compressed, bluntly triangular or ovate
spikelets, dangling at the end of capil-
lary branchlets ; luith membranous,
loosely imbricated, concave and in-
flated paleoe and glumes, and 6 — 8

flowers,

Briza media, L.

The much rarer B. minor, L. is an annual and smaller.

VIl] FLOKAL CliARACTEKS 113

©0 Spikelets sm(dl and numerous, more or
less elongated and pointed, not dangling:
glumes and pnlece not inflated.

Poa and Festuca (see X3. 116) are difficult genera for the beginner;
several of the species vary considerably in detail. Generally speak-
ing the spikelets of Festuca are hard, harsh and sharply pointed, or
with short or evident awns ; in Poa they are softer, and with
blunter points, and never awned. The most obviously awned
species oi Festuca have more or less setaceous leaves and contracted
inflorescences (see p. Ill), Some of the mountain species of Poa
are extremely variable in small characters.

s Reed-like aquatic^ with obtuse glumes rounded
dorsally ; the large richly branched panicle
bearing numerous 5 — 10 jlowered spikelets.
Sheath entire or nearly so. No web to the
palece.

Glyceria aquatica, Sm.

For other reed-grasses, see note, p. 103. Glyceria Jluitans has a
more contracted panicle and usually more flowers in the spikelet &c.
(see p. 111).

= = Meadow and pasture grasses <S:c.

small. Glumes more or less keeled and
acute. Sheaths split.

Poa.

I Spikelets very small and contcdning 2 — 3
jlowers only. Stem slender, terete and
rough; ligule long and acute, palea ivith
prominent latercd nerves.

P. trivialis, L.

The flowers arc fewer than in any other Poa, and may be only two.
P. neraoralis, with 3 — 5 flowers, may also occasionally be found with
two only : it differs from others in its more acute glumes, smooth
stem and sliort ligule.

P. pratensis diflers in its creeping stolons, short ligule and more
numerous 4—5 flowers, and in the indistinct nerves of the palea.

W. 8

11-i CLASSIFICATION ACCOEDING TO [CH.

II Spikelets 4 — 6 flowered.

£3 Annuals, about six inches high, with rela-
tively large and numerous spikelets for so
S7aall a panicle. No " v;eh " at the base of
the palece.

P. anima, L.

This is the small grass so common as a weed on roadsides and
on lawns, flowering even in winter. For other annual species of
Poa — P. rigida, P. loliacea and P. procumhens — see note p. 108 and
p. 111.

= = Perennials.

A ^Vith creeping stolo7is.

X Stems and leaf -sheaths flattened. Panicle
someiohat close and secund, some spike-
lets being nearly sessile.

P. compressa, L.

AW Stems and leaf-sheaths terete. Panicle
spreading widely.

P. pratensis, L.

A A Without creeping stolons. Stems and
panicle slender, round. A shade-plant.
P. nemoralis, L.

The rarer species of Poa are P. bulbosa with the stems swollen
below ; P. alpina, also slightly bulbous and often viviparous ; P. laxa
an allied Highland species ; and P. distans a maritime form allied
to P. maritima (see p. 111).

** Spikelets with awns or with sharp terminal
points (awn-points) to the glumes or palepg.

In some species and varieties of Festuca aM^ns are not evident
(see p. 116) : the hard palese simply end in acute or acuminate
points, but these are sharp and in most cases much more so than in
any Poa. When not so evident, the student will probably think
the specimen is a Poa and the flora must be consulted.

VllJ FLORAL CHA11ACTER8 115

The difficulty is most likely to occur with varieties of F. ovina
and F. elatior : in the former the leaves are narrower, setaceous and
stiffer than in any Poa. The ribbing of the leaf, the ligule, and
other characters of the vegetative organs (see pp. 45 and 50) will
help in these doubtful cases.

t Awns terminal, or sub-terminal ; often very short
or nearly obsolete and the palese merely drawn
out at the tips to a hard sharp awn-point.

© Aivns long and sub-terminal, inserted

between the teeth of the cleft apex of the

palece. Sheaths entire. Panicle usually

nodding.

Bromus.

With the exception of Festuca Myurus and one or two other rare
Fescues with setaceous leaves, Hordeum and Br achy podium are
the only other genera with awns much resembling the Bromes.
The former has a totally different inflorescence, and in the latter the
spikelets are practically sessile (see p. 107).

= Spikelets short and fat, and relatively heavy,
Palece hroad and distinctly nerved. Aivns
fine, about as long as the palece.

B. arvensis, L.

There are several varieties, of which B. secalinus with a looser
panicle, and B. mollis with a more compact panicle and very
downy, are the chief.

= = Spikelets lanceolate and loith conspicuous
aivns. Nerves on the palece obsolete.

X Panicle conspicuously loose and drooping
and awns long, palece narrow and elon-

Sheaths with long often rejicxed hcurs.
A shade-grass over three feet high.

B. asper, Mull.

116 CLASSIFICATION ACCORDING TO [CH.

zz Sheaths downy. A iveed of open lands
and hedges^ two feet or less.

B. steriUs, L.

B. giganteus is rarer than B. asper and has smaller spikelets
and more slender awns. B. maximus and B. madritensis are rare.

0© Aivns, if 'present^ merely the points of

the palece, very short or obsolete. Sheaths

split : ligule short.

Festuca.

= Leaves flattened. Panicle somewhat dose.
Often tall grasses.

z Meadow-grass., with 5 — 6 to a dozen or
more flowers in the spikelet.

F. elatior, L.

zz Shade-grass, with 4 — 5 floioers only in the
spikelet.

F. sylvatica, Vill.

= = Leaves sidndate or setaceous, at least below.
Mountain pasture grass, usually small.

F. ovina.

Concerning difficulties between Foa and the awnless forms of
Festuca, see p. 114. F. elatior and F. sylvatica are practically awn-
less, the awn-points being merely the acuminate tips of the palese.

The long-awned species of Festuca have compact stiff panicles
and narrow or setaceous leaves (see p. 111).

Regarding varieties of F. ovina, see p. 112.

ft Awns, twisted below and bent above, inserted
into the middle of the back of the bifid palea or
below it.

© Awns long and conspicuously projecting
from the spikelet, which is gaping and
contains 3 — 5 flowers. Leaves flat.

Avena.

VllJ FLORAL CHAltACTERS 117

EH Tall annual corn-weed^ with large (18 —
20 mm.) heaoy^ pendent, hairy spikelets on
the long slender stalks of the lax open
panicle. Leaves glabrous.

A. fatua, L.

This is the so-called AVild Oat, and the type of this group.

£E = Tufted perennials with spikelets more or less
erect on stiffer stalks, the panicle therefore
less open.

z Panicle nearly simple ; spikelets silvery or
reddish, 12 — 15 mm. long.

A. pratensis, L.

zz Panicle branched but not eery open;
spikelets glistening yellow and only
5 — 6 mm. long.

A. flavescens, L.

There is no other genus closely resembling Avena. The
superticial likeness of some Bromes disappears at once on exami-
nation. The spikelets of Aira are much smaller, and the leaves
quite different (see below and p. 47).

0© xiwns fine and Itair-like and not con-
spicuously protruding from the spike-
lets; the latter small, 2 — 5 nun. Flowers

two in each spikelet.

Aira.

= Coarse and tall tufted grass with flattened,
harsh, and conspicuously ribbed leaves: the
very short awns hardly protruding.

A. ccespitosa, L.

No other grass can be confused with this if the very high ridges
of the leaves are observed (see p. 47).

= = Small grasses mth setaceous or very narrow
inrolled leaves. Awns sligldly protruding.

liy FLORAL CHARACTERS [CH. Vll

jf Palea distinctly hijid at the apex: awn
nearly twice its length. A very small
grass about six inches high: leaves sub-
ulate, fine and short.

A. cai^yophyllea, L.

XX Palece almost imperceptibly bidentate:
awn not much longer than palea. About
12 — 18 inches high: leaves inrolled.

A. flexuosa, L.

Other species of Aira, with more condensed inflorescences, are
dealt with on p, 112. Agrostis is distinguished by the leaves and
one-flowered spikelets (see p. 104). Poa and Catabrosa have no
awua.

CHAPTER VIII.

THE FRUIT AND SEED-

The stigma of an ordinary grass consists of two divari-
cating plume-like structures composed of thin-walled cells.
When the palese open these stigmatic phimes protrude,
one on either side, and readily catch pollen shed from the
dangling stamens and carried by the wind, and since the
pollen of the same flower is usually shed at a time when
the stigmas of many neighbouring plants are mature,
there is every opportunity for cross-fertilisation. (Fig. 33.)

In some cases, however, e.g. Anthoxaiithum, Alopecurus,
the flowers are proterogynous, the stigmatic plumes being
ready for pollination some time before the pollen is shed
from the anthers of the same flower ; whereas in most of
our grasses the pollen begins to scatter before the stigmas
are ready (protandrous). Among exotic grasses, many are
dioecious or monoecious — i.e. the flowers contain stamens
only or ovary only, on each plant, or on different inflores-
cences of the same plant respectively — and even in our
own Holcus and Arrhenatherum this state of affi\irs is
partially represented, since one flower of the spikelet is
male only.

In some grasses, e.g. Rye, however, it appears im-

120

POLLINATION

[CH.

probable that cross-fertilisatioii ever occurs, since the
paleae do not open, and the pollen falls on to the stigma
direct ; and in Leersia and
the foreign Amphicarpum
the spikelets are completely
cleistogamous, those of the
latter being on stalks close
to the ground Nvhich push
the flowers into the soil,
where pollination and fruc-
tification are accomplished.
Hybrid grasses are by
no means uncommon. To
say nothing of the numerous
cross-bred Wheats and Bar-
leys, artificial hybrids have
been raised between Wheat
and Rye. In the Maize
an astonishing number of
selected cross-breeds have
been obtained, and, among
others, certain forms in
which the seeds have a
violet outer layer and a
sugary endosperm, are found

to transmit these characters to the resulting seed of a
variety which would normally have produced seed with
white outer layers and starchy endosperm, if the pollen of
the former is used on the stigma of the latter. Such
direct influences of the pollen are termed Xenia.

Fig. 37. Pollen-gi-ains adherent to
the papilliB of the stigma, on
which they germinate, sending
the pollen-tubes down between
the cells. Kerner. x about 100.

VI 1 1]

FERTILISATION

121

When the pollen -grain, hav
stigma, iias begun to germinate,
creeps dowji between the cells
of the stigma, and hands over
its enclosed nuclei to the em-
bryo-sac, where fertilisation of
the egg-cell is accomplished,
by the fusion of one of the
pollen nuclei with the nucleus
of the egg-cell. As the result-
ing embryo developes, the sac
becomes filled with endosperm-
cells charged with starch-
grains or sugar, and in the
ripe seed the embryo is always
found affixed laterally and be-
low to this endosperm — a point
of distinction from Sedges,
where the embryo is buried
in the endosperm.

The ripe seed fills the
ovary, and its outer walls
usually fuse with those of
the carpel, forming the well-
known Caryop^is or "grain."

If such a " grain " is care-
fully examined, three chief
parts are visible in addition
to the embryo. (Fig. 38.)
Firstly, we find on the outside

ing adhered to the hairy
the resulting pollen-tube

Fig. 38. Longitudinal median
section of the caryopsis of a
grass — e.g. LoUuiii ( x about
35). p, pericarp; t, attach-
ment to axis; m, position of
micropyle; I'J, endosperm ; A,
its aleurone layer; /, folded
leaves of pUunule; r, radicle;
r", secondary roots ; RC, root-
cap ; s, scutellum. The dark
line c represents the surface
where the face of tlie scu-
tellum is applied to the endo-
sperm and where absori)tion
of tlie latter takes place.

the fused seed- and fruit-

122

HISTOLOGY OF THE GEAIN

[CH.

coats, differing in the number of layers and in the micro-
scopic characters of the cells, some of which characters
can be employed in diagnoses. (Fig. 39.)

Secondly, the great mass of the " grain " internally is
composed of delicate cells filled in most cases with starch-
grains, the sizes, shapes and arrangement of which can
also be employed for diagnoses— e.g. the compound grains
of the Avenese and Festucese are different from the simple
polyhedral or rounded grains of the Andropogonese and

Fig. 39. Transverse section (highly magnified) through a grain of
Brachypodiuvi pitmatum taken about half-way up. 1, epidermis;
2, pericarp; 3, remains of the true seed-coat; 4, vascular bundle;
5, remains of nucellus; P, epidermis of nucellus; G, aleurone
layer: remarkable in being several cells thick; E, endosperm.
Harz.

Maydese, and some races of Maize have sugar and soluble
starch instead of grains of the latter.

Vlll]

FJiUITS OF GRASSES

123

Thirdl}^ the outermost layer or layers of cells of the
endosperm are filled with proteids, and are kiiowu as
the Aleurone layer. (Fig. 38, A.)

The embryo consists of the folded embryonic leaves in
bad (plumule) above, which will grow up on germination
as the shoot or " spear," the short primary root (radicle)
below, with in many cases two or more secondary rootlets
already showing in its tissues, and
from the common " collar " uniting
these a more or less prominent
shield -shaped organ (scutellum)
standing out laterally in contact
with the endosperm, the dissolved
contents of which it absorbs on
germination. (Fig. 38, s.)

Although typical grasses form a
caryopsis as described, exceptions
occur. In the exotic Sporoholus,
Eleusine, Crypsis and HeleocJiloa the
fruit becomes truly dehiscent, the
seed being loose in the fruit, and the
latter opens and allows it to fall out ;
and in many Bamboos the seed is
loose in the achene, while in a few
cases — e.g. Melocanna — the fruit is
fleshy and may be as big as a
walnut.

Returning to the typical grasses.
When the fiuit ripens in the spikelet, several events ma}
happen.

Fig. 40. Triodia decum-
bem. a, "seed," nat.
size ; h, ditto, x 6.
Note the basal hair-
tuft and rachilla, ftnd
the ciliate, toothed
outer palea with a
short awn-point, en-
closing the inner more
delicate palea. Be-
tween the two lies the
caryopsis. Nobbe.

1:>4

DISARTICULATION OF "SEED

[oh.

Ill most of our grasses the caryopsis comes away
trapped between its two jjalea^, and the latter bring away
with them the small piece of the axis of the spikelet on
which they stand : this bit of axis — the rachilla — often
affords valuable characters in
diagnosis. (Fig. 41.) It is the
l^air of palese enclosing their
car3^opsis which goes by the
name of " seed " in most of our
grasses. (Fig. 40.)

In a few cases, however, e.g.
Panicum, the spikelet comes
away as a whole, so that here
the " seed " consists of the
glumes, enclosing one, two or
more pairs of palese with their
contained caryopses.

Even among our native
grasses, however, cases occur
where the separation takes
place below some of the
glumes, and so the "seed," as
met with in samples, consists
of glumes as well as enclosed
paleae and caryopsis — e.g. An-
thoxantham, Alopecmms, &c. —
and some care is necessary in
examining grass " seed " in these circumstances (see p. 134).

Interesting biological adaptations are met with in the
distribution of grass " seeds." The very small and light

Fig. 41. Diagram of a spikelet
of a grass — e.g. Festuca —
comprising six matured
flowers and their paleae,
embraced by the two
glumes (^V) at the mo-
ment of disarticulation as
the fruits ripen. The small
piece of axis (a) left attach-
ed to each segment is the
rachilla R. At p'^ the tip of
the inner palea is visible
protruding from the outer
one p^ : in the rest it is still
enclosed in the latter.

VIIl] DISSEMINATION 125

fruits of Agrodis easily foil and are scattered by the wind,
but in many cases the glumes (Holcus) or paleae (Briza)
are expanded and serve as "wings" offering extensive
surfaces to the wind. In Arwido, Galamagrostis, Aira,
&c., fine silky haira attached to the rachilla serve a
similar function, reminding us of the coma of true seeds
and the imppus of Composites. In Hordeum juhatum of
the prairies, the axis breaks up and the disarticulated
portions with their attached tufts of fruits are blown
away by the wind, and something similar occurs in our
own H. murinum to a less extent. In the exotic Spinifex
whole heads of fruits are thus detached and blown
over the sands as " tumble weeds."

In Stipa pennata we have an example of perhaps
the most complex of all such adaptations: the exceedingly
long awn terminating the palea is plumose at the upper
end and twisted below, and the hard sharp rachilla at the
base of the fruit is furnished with short, stiff hairs directed
upwards. The plumed awn serves as a wind surface, the
whole fruit flying like an arrow through the air. The
stiff hairs below serve to fix the lower end between
particles of soil, and by their alternate drying and wetting,
the warping of these and of the twisting and untwisting
aw^n drives the sharp base into the soil. (Fig. 42.)
Similar mechanisms exist in Avena and others.

These bristles and awns also subserve dissemination
in other ways, especially by clinging to the w^ool and fur
of sheep and other animals, and cases occur where the
twisting awns and reflexed hairs on the hard pointed
fruit-base drive the latter into the bodies of sheep with
fatal effects — e.g. Stipci capillafa in Russia, S. spartea in

Fig. 42. Awncd fruit of Stfpa. The reflexed stiff hairs and hard point
favour penetration into tlie soil. The long twisted awn performs
hygroscopic movements, and its terminal plume offers surface to the
wind. Lubbock.

CII. VIIl]

SEED -CHARACTERS

127

America, Aristida Jnjgroiiietrica in New Zealand, Hetero
pof/on contortus in New Caledonia.

The driving action of even small
reflexed asperities on awns is well
illustrated by the fruits of Hordeum,
which are often made by children to
creep up the sleeve.

When we come to examine the
external features of the "seeds" of
grasses — usually the caryopsis en-
closed in one or more palege, but
sometimes in glumes as well — the
following diagnostic characters are
of importance.

The size varies from lengths of
2 mm. or less (Poa, Aira) (Figs. 43,
44) to 15 — 20 mm. or more {ArrJie-
natheruiii) (Fig. 47) and distinction
must be made between the various
characters of the caryopsis devoid of its coverings (palea?,
glumes) and such as reallj^ belong to the latter.

The caryopsis proper may be short and stout and
devoid of a groove — " Millet-seed " type (Fig. 45) — but is
oftener elongated, like a grain of Wheat, and then has
the characteristic longitudinal groove on the face opposite
that where the embryo is situated (Fig. 4(3). Details of
shape — e.g. cylindroid, fusiform, flattened, &c. — are also of
diagnostic value.

In many cases the " seed," consisting of the caryopsis
closely compressed between the pale?e, is boat-shaped, e.g.

Fig. 43. Poa annua,
d, the " seed," nat.
size; a and b, ditto,
X about 7 ; c, cary-
opsis, iiatni-al size
(above) and x about
7. Note the ribs
and silky keel. No
"web." Nobbe. Cf.
Figs. 54—56.

128

SHAPES OF '■' SEEDS

[CH.

LoUinn jierevne, Festvca elatior. If this ''boat" is long
and narrow it may be termed barge-shaped, e.g. Brachy-

Fig. 44. Aira cce-<ipitosa. The
minute " seed " (nat. size) is seen
to the right, and the caryopsis
(nat. size) to the left of c, the
caiyopsis, x 8. a and h, the
'*seed,"xlO. The basal awn
is about as long as the palea,
and the rachilla is very hairy.
Nobbe.

Fig. 45. Phleum pratense. Mil-
let-seed type, a, "seed," nat.
size; b, ditto, x about 7; d,
caryopsis, nat. size; c, ditto,
X 7. The rounded caryopsis
in h is only loosely covered by
one palea. Nobbe.

podium sylvaticum, &c. (Figs. 71, 72) : if short, broad, and
open or shallow, the term coracle-shaped seems to apply,
e.g. Bromus arvensis (Fig. 73).

Fig. 46. Boat-shaped " seed" of Glyceria nuitans. a, nat. size; b and
c, X about 6. d, caryopsis, x about 10. Note the 5—7 strong
nerves, and the slender cylindrical rachilla. Cf. Figs. 57 and 58.
Kobbe.

VTIl

AWNS

129

Further important distinctive characters are obtained
from the absence or presence of awns, and the peculiarities
— length, stitfness, &c.— of the latter. The awns may be

Fig. 47. Arrhenatherum avena-
ceum. The "double seed" (a
and b) consists of two pairs of
palese with their enclosures.
The lower pair (7) are devoid
of fruit, and the outer palea
has a long twisted and kneed
basal awn : the upper pair {j3)
enclose the fruit, and the palea
has a short straight awn. Note
the stiff basal hairs, a, nat.
size ; b, X about 6; c, caryopsis,
nat. size; d, ditto, x 6. Nobbe.

Fig. 48. Loliuvi temulentu))i.
Type of boat-shaped "seed"
with sub-terminal awn arising
from between two teeth, c,
"seed," nat. size; a and b,
ditto, X 6. Note the large
smooth rachilla. Nobbe. Cf.
Fig. 57.

130

TERMINAL AWN

[CH.

Straight, hooked, or kneed (i.e. sharply bent) ; twisted or
not ; smooth or serrulate. They may he inserted at the
base or near the middle of the back of the investing
palea, or glume, or near its apex, as indicated by the
terms basal, dorsal, sub-terminal (see Figs. 47 — 50).

Some difficulty arises in connection with terminal
awns. In some cases there is a true
awn — i.e. a distinct bristle or hair \ /

— at the apex of the palea, and \/

apparently continuing its substance
wdthout interruption ; but in most
instances close examination shows
that this awn arises from between
two minute teeth, and is really in-
serted at the back of the slight de-
pression l^tween them — e.g. Loliuni
temulentum (Fig. 48), Brachypodium
pinnatum (Fig. 77), &c.

In another class of cases the awn
appears to be really the prolongation
of the palea — e.g. Nardus (Fig. 81),
Festuca Myurus (Fig. 80), &c. — and
when it runs out into a distinct
bristle we may speak of a terminal
awn without staying to discuss
w^hether or no it is really terminal
in development.

In Arundo, Cynosurus and some
Fescues, where the palea tapers off into a stiff long point,
I have not spoken of it as an awn, but have described the

Pig. 49. Agrostis Spica-
venti. c, "seed," nat.
size; a and b, ditto,
X about 9. The long
slender awn is insert-
ed below the bifid tip
of the palea. Nobbe.

VIII

KACHILLA, "WEB," ETC.

131

palea as tapering into a sharp point (awn-point). It must
be admitted that the distinction is somewhat artificial, but
it has its advantages in practice.

Fig. 50. Bromussterih's. a, "seed,"
nat. size; b and c, ditto, x about
2. Nobbe. Cf. Figs. 80 and 81.

Fig. 51. Fc'ttiica sylvatica. a,
"seed," nat. size; b and c,
ditto, X 8. Nobbe. Cf. Fig. 78.

The rachilla (Fig. 41), when present, often affords good
characters, and in a few cases is relied on for the dis-
tinction of "seeds" otherwise much alike — e.g. Lolium
perenne and Festuca elatior ; and similarly with the
presence or absence of hairs {Digrapliis, Arundo, &c.)
or " web " (Poa) at the base of the " seed." (Figs. 55, 69.)

On germination the primary root of the embryo
usually emerges and at once plunges into the soil, but
soon ceases to grow, and the secondary roots (and sub-
sequently adventitious rootlets from the lower internodes)
soon give the peculiar fibrous character so well known in
grass-roots.

9—2

132 GERMINATION [CH.

The plumule either pushes out from the same end of
the caryopsis as the root (e.g. Wheat, Rye) or drives its
way between the coats to the opposite end (e.g. Barley)
and appears as a pointed cylinder of rolled leaves (the
" spear ") the outermost of which is sheath only, no lamina
being developed. As Darwin showed, the pointed apex of
such a plumule is hardened, facilitating the piercing of the
soil above, and when the blade attains the open air it
performs spiral movements during growth, indicating that
similar attempts to rock from side to side have aided the
plumule in forcing its way through the soil. It has also
been shown that the apices of roots and plumules are
sensitive to differences of temperature, of light-intensity,
moisture and contact, all of which aid the seedling in
establishing its position in the soil and in liberating the
" spear." For particulars the student should read IJarwin's
Poiver of Movement in Plants.

With regard to the established seedlings of grasses,
many interesting details of structure are to be found in
them. I have not sufficient material to draw up a
diagnostic arrangement of grass-seedlings, but it is
evident that such could be doue. It may be useful to
illustrate this by the following tabular view of the
characters of the larger seedlings of our common cereals,
in part adapted from Vesque and Percival ; though I find
that some variations may occur, especially in the develop-
ment of the auricles.

villj classification of seedlings 133

Seedlings.

I. First expanded aerial leaves broad, bright green,
with 18—24 ribs.

Barley.

The blade tends to twist to the left : auricles, when well de-
veloped, long, pointed, and claw-like, embracing the glabrous sheath
in front. Ligule long, membranous, pointed and irregularly toothed.
The plumule emerges at the upper end of the grain, and the embryo
has 5 — 6 .secondary roots.

II. First aerial leaves narrower, with not more than
11—13 ribs.

A. Ligule long, rounded and toothed.

Wheat

The blade tends to twist to the left : auricles filiform and embrace
the densely pubescent sheath. Leaves g]-oen. Embryo with three
roots.

B. Ligule short and toothed. Leaves with a reddish

cast.

(a) Blade and sheath softly hairy, the latter with scattered
long hairs, the former tending to twist to the left.

Bye.

The first leaf-sheath purple. Auricle-claws more triangular and
smaller than those of wheat, and the accompanying bristles are
fewer and shorter. Embryonic roots foiu*.

(6) Blade and sheath glabrous or merely ciliate or silky,
the former tending to twist to the right.

Oat.

Auricles filiform. The plumule emerges above. The embryo
has three roots.

A curious phenomenon is observed in some grasses
growing in high latitudes, or mountainous regions, or in

134 VIVIPARY [CH. VIII

moist situations. The flowers, or even entire spikelets,
grow out into minute leafy buds, with rudimentary roots
at the base, and fall off like the bulbils of other mono-
cotyledons, taking root directly in the damp soil. The
phenomenon must be looked upon as a case of apogamy,
since the development of sexual organs is entirely 23assed
over ; the parts which would normally have become ovary
and stamens being transformed into leaves. In some
species or varieties — e.g. Poa alpina, Festuca ovina — this
viviparous condition may coexist with normal flowers and
spikelets ; in others — e.g. Poa laxa, var. stricta — only the
viviparous state occurs.

In the following arrangement the student should note
that the terms " Seed " and " Fruit " are used in the
ordinary sense of the farmer and seedsman : by the
former is meant the *' seed " as it comes in samples into
the market, when the true fruit or grain (Caryopsis) is
almost invariably invested by adherent "chafif" — i.e.
palea? or glumes or both. When the word Caryopsis is
employed, I mean it strictly in the botanical sense ex-
plained above. In Hordeum, for example, we never see
the true fruit, the grain consisting of the caryopsis with
palese so closely adherent to it, that we are apt to take
them as part of the grain itself. The true seed, in the
strict botanical sense, is never seen as a naturally separate
organ in our native grasses; and, as already explained,
only very few exotic grasses ever shed it — e.g. Sporoholus.

CHAPTEE IX.

CLASSIFICATION OF GRASSES BY THE
"SEEDS" (GRAINS).

I. "Seed" rounded (Millet-seed' type). Caryopsis
ovoid or sub-globose, devoid of distinct groove,
and distending the awnless paleae, or falling
out free.

A. Glumes cuspidate, " fruit " yellowish.

Phleum pratense.

The student should familiarise himself with the "seed"
of Phleum pratense, as a type, and an important grass
easily obtained pure, but sometimes with minute round
seeds of weeds intermixed.

Phleum pratense, L. (Fig. 45).

Palea 2*3 mm. long, live-ribbed, with a short point,
delicate but hard, smooth, with a silvery lustre. Inner
pale two- nerved. Closely investing the yellow-brown

1 This term does not necessarily imply any botanical relationship
with the true Millets {Panicwn), but merely that the caryopsis is short
and broad as in these grasses.

186

CLASSIFICATION OF

[CH.

caryopsis, which easily falls out and is ovoid-acute, about
2 mm. long by 1 broad, and finely punctate.

The much rarer F. arenarium and the very rare P. Boehmeri and
P. asperiLin also come here.

Phleum is not easily confounded with any other of our grasses,
and Briza and (Jlyceria are ahnost the only other common grasses of
about the same size of which the caryopsis often falls free from the
palea ("naked fruits"). Glyceria is longer and corn-shaped, and
Briza usually larger. Anthoxantimm and Phalaris are easily dis-
tinguished. Agi'ostis is smaller and " corn-shaped." Certain species
of Panicwn present resemblances, but the enveloping paleae, &c. are
very different. Melica also occm's as " naked fruits," but is rarely
seen, and its colour and brilliant lustre distinguish it.

B. Glumes not cuspidate. " Fruit " not yellow.

(a) " Fruit " white, owing to the closely investing

palea.

Milium effusum.

A common grass, but not often met with in "seed" grasses. It
is eagerly eaten by birds.

Milium effusum, L. (Fig. 52).

Palea about 3 mm. long, with
few nerves, closely investing the
caryopsis : the seed is ellipsoid -
acute, slightly compressed, and 2' 2 —
2-7 mm. long. The inner pale be-
comes hard and shines like porcelain.

(b) *' Fruit " dark-brown shin-
ing ; slightly flattened and

grooved.

Melica.

Fig. 52. Milium effu-
sum. " Seed," a,
nat. size; h and c,
X 7. Nobbe.

IX]

" SEEDS "

137

Melica is rarely met with as " seed." When it is, it lias to be
distinguished from the other " Millet-seed " types which readily fall
as naked fruits— see Phleum^ Milium, &c. Agrostts, Ghjceria and
other corn-shaped " seeds " are easily distinguished.

Melica nutans, L. (Fig. 53).

*' Seed " coracle-shaped. Palea broad, parchment-
like, elliptic convex, 5 — 6 mm. long, 5—7 nerved and

Fig. 53. Coracle- shaped " seed " of Jlelica nuttois, showing the broad,
ribbed and keeled palea (c), and small rachilla (d). a, the "seed,"
nat. size ; c and d, ditto, x 8 ; 6, the caryopsis, nat. size ; e and /,
ditto, xlO. Nobbe.

keeled, awnless, loose, purplish. Caryopsis ellipsoid-acute,
2 — 3 mm. long, and easily separating, wrinkled, dark
shining brown as if lacquered.

J/, uniflora, Eetz. is commoner and very similar, but neither is
often met\vith in "seed" grass, except as impurities among Fescues.

The rare Panicum Crus-galU and allies, and the rice-like Leersia
oryzoides as well as Cynodon Dactylon, come here.

Panicums may occur in grass " seed " from America : Burchard
describes them in detail.

138 CLASSIFICATION OF [CH.

II. "Seed" long" (Corn and Barley type). Caryopsis
oblong or flattened, usually trapped between the
boat-shaped palese : if otherwise, with an awn.

A. "Seed" awnless. There may be a short sharp point
to the palea (mucronate), but no prominent hair- or
bristle-awn exceeding half the length of the palea.

(a) A " web " or tuft of hairs at the base or on
the rachilla.

(1) Hairs of basal tuft silky and erect.

* Pencil of hairs as long as palea or longer.

Calamagrostis lanceolata, Roth.

Palea 3 mm. long, thin, two-toothed and with a short
bristle at the apex.

Other species of Calamagrostis are awned. None occurs as an
ordinary impurity in "seed."

Arundo Phragmites, L.

Palea narrow and long, 10 — 11 mm., delicate, entire,
tapering to an acuminate point, violet, three-nerved,
smooth. Caryopsis about 2 mm. A pencil of long silky
hairs on the rachilla.

The long acuminate point is almost an awn.

Calamagrostis also has long basal hairs : both are useless grasses
agriculturally. For Glyceria see note, p. 146. Avena, Aira and
Psamma are easily distinguished.

** Pencil of hairs short.

t Palea mucronate, 11 — 12 mm. long: caryopsis
4*5 mm.

Psamma arenaria.

ix] "seeds" 139

Digraphis differs in the stout carjopsis, smaller size, double hair-
tuft. AruTido has a long pointed palea and long silky basal hairs
and is larger.

Psamma arenaria, Beauv.

Palea 11-5 mm. ovate-lanceolate, papery, 4 — 5 nerved,

as rolled round the fruit about 13 mm. diameter, yellow,

and with a small tuft of stiff fine hairs at the base. Mere

trace of awn, sub-terminal. Fruit 4 — 5 mm. long, obovate,

pale- brown.

A shore-grass, not often seen as " seed " : more valuable as a
sand-binder than as fodder, though the young shoots are grazed.

ft Palea acuminate, and only about 4: mm. long:
caryopsis 1"4 mm.

Digraphis arundinacea.

A Fen-grass, but coarse and not in use except the young growth,
and for thatching.

Digraphis arundinacea, Trin.

Palese ovate-lanceolate, nerveless and awnless, but silky
with double basal hair-tuft, and polished at the base ;
smooth, hard and shining, and closely investing the
caryopsis which has no groove. Dark grey in colour. The
glumes are without awns or wings, and are left behind.

The allied Phalaris canariensis has wing-like keels to the glumes.

Triodia also comes into this group, \vith short basal hairs ; but
its broad ciliate palea, 6 mm. long, has a short mucronate x^oint
between two teeth (Fig. 40).

(2) Hairs at the base forming a fluffy " web."
Falece thin, 2 — 3 mm. long.
Poa pi'atensis.
P. trivialu.
P. compressa.
P. nemoralis.

140

CLASSIFICATION OF

[CH.

The "seeds" of Poa proper are nearly all small — not more than
3 — 4 mm., more or less lanceolate, with tough, keeled glumes, and
when "webbed" tend to adhere together as if stuck with cobweb.
The keeled glumes give them an angular appearance — triangular
in section — and make them tend to lie on the side. Eachilla
evident. Nerves of palese distinct.

Poa pratensis, L. (Fig. 55).

" Seed " 2 — 3 mm. long, brownish : caryopsis about
1 — I'o mm. Outer palea acute, indistinctly 3 — 5 nerved,
edges and keel, silky; margins overlapping the hyaline
inner palea.

The " web " looks like hyphse of a mould.

Caryopsis ellipsoid-acute, with traces of the stigma.
It falls easily. No distinct groove, section somewhat
triangular. Rachilla truncate.

Fig. 54. Poa ncmoralis.
c, the minute "seed"
(to the right) and
caryopsis (to the left)
nat. size. a, the
" seed," X 8 ; 6, the
caryopsis, x 8. Traces
of a basal " web," not
shown here, occasion-
ally occur. Nobbe.

Fig. 55. Poa pratensis. Fig. 56. Poa trivialis.

Type of a " webbed
seed." a, " seed,"
X about 7 ; 6, cary-
opsis (inverted), x 7.
Between are the same,
nat. size. Note the
nerves on the palea
and the conspicuous
"web" at the base a.
Nobbe.

a,

seed," nat. size

and X 8 ; t, cary-
opsis, nat. size and
X 7. Note the con-
spicuous " web."
Nobbe. Of. Fig. 43.

Poa compressa, L.

Palea obtuse, nearly glabrous and nerveless, or faintly

IX] " SEEDS " 141

8 — 5 nerved and with a faint web. It is close to
P. pratensis.

Poa trivialis, L. (Fig. 56).

" Seed " 2 — 2'5 mm., and with a bluish or bronzed
cast. Caryopsis 1 — 1*5 mm.

Palea acute, distinctly five-ribbed, glabrous, the margin
scarcely overlapping. Caryopsis grooved, blunt and more
tightly held in the palea.

P. trivialis differs from P. pratensis chiefxj in tlie distinct ribs
and smoother palea, grooved caryopsis, and bluer hue.

P. neynoralis, L., hardly differs from P. trivialis, but
the palese are sub-acute, nerves obsolete, and scarcely
hyaline at the margins. The " seed " is shorter and more
acute, and the colour less pronounced, and with hardly a
trace of hairs (Fig. 54).

When the basal hairs are absent this should go with
P. annua, &c. (see p. 146).

It is practically impossible to distinguish these species by the
" seed." Care is necessary to distinguish Koeleria, which is somewhat
larger in size, keeled, compressed and nerved similarly, but is more
pointed and cm-ved and paler yellowish white in colour. Hard and
devoid of web or hairs. Aira is distinguished by the awn : Agrostis
by the very different paleae and caryopsis.

The other Poas are devoid of web, though they may have hairs
below, and require very careful examination. The whole group is
excessively difficult to deal with in "seed," and a special study of it
is needed, since several species are important, and it forms a type.

(b) No web or pencil of hairs below the " seed."

(1) Apex of palea rounded, blunt, notched, or at
most bluntly pointed, but with no trace of
awn- or bristle-tip.

142 CLASSIFICATION OF [CH.

* Palea inflated, round-backed and somewhat
winged, membranous.

Briza media.
B. minor.

Briza media, L.

Palese blunt, 2*5 — 3 mm., without lateral projections,
markedly convex — almost conduplicate ; nerves several.
Caryopsis ovoid, 1"5 — 2-5 mm., dark brown.

Sometimes called a good grass, but meagre and only found in
poor meadows in this country.

It shoukl perhaps go with the " Millet-seed " type and should be
compared with Phleum, Melica^ Panicum, &c. " Seed " seldom met
with.

B. minor is smaller.

** Paleje not inflated or winged.

t Palece hroad^ flat and truncate, prominently three-
rihhed. Caryopsis 2 mm. long.

Catabrosa aquatica, Beauv.

Cattle like it, but it only grows in ditches &c. in water-meadows :
distinction from Glyceria aquatica easy if the palese are examined.

+t Palece acute or sub-acute, boat-shaped.

© Palece and " seed " at least 6 — 8 mm. long.

= Rachilla flattened or angidar, and tapering
below.

Lolium 2^erenne.

Occasionally awned, and then less easily distinguished from
L. temAdentum. One of our -most valuable grasses. It forms a
distinct type of boat-shaped " seeds."

Lolium p)6renne, L. (Fig. 57).

Palea distinctly five-ribbed, glabrous, oblong-lanceolate,
obtuse or sub-acute, awnless, about 7 mm. long. Margins

IX]

" SEEDS '

143

membranous. Inner palea nearly as long, delicate,
ciliate.

Rachilla short, flattened and angidar, tapering below
(see Festiica elatior).

Caryopsis about 3'5 mm. long, obovate, yellowish
brown.

Fig. 57. Lolium perenne with typical
boat-shaped "seed." a, natural
size; h and c, x about 8. rf, cary-
opsis, X 8. The rachilla, in c, is
broader upwards and flatter than
in Fig. 58. Nobbe.

Fig. 58, Festuca elatior, var.
pratensis. Lettering and sizes
as in Fig. 57 : compare the
more cylindrical and slender
rachilla. Nobbe.

Although Bromus mollis, Eolcus lanatus, &c. occur as impurities,
they arc easily distinguished : the real difficulties are with Festuca
elatior and F. pratensis.

144 CLASSIFICATION OF [CH.

= = Rachilla cylindrical.

Festuca elatior.

This is an important grass, and should be thoroughly mastered
as a type of the boat-shaped " seed."

This, with Lolium, Agropyrum, other Fescues, and even some
Bromes and Poas, will give trouble until the student thoroughly
masters the importance of the minute characters of size, nervature,
of the rachilla, awn, palea, &c.

Festuca elatior, L. (var. pratensis) (Fig. 58).

Palea ovate-lanceolate, five-nerved, slightly scabrid,
with a slight membranous margin and cilia, rounded
back, and no awn. 6 — 7 '5 mm. long.

Caryopsis oblong-obovate, somewhat flattened, hardly
grooved and adhering to the palese, about 3 — 3'5 mm.
long.

Rachilla cylindrical, smooth.

The other varieties of F. elatior cannot be distinguished by the
" seed " alone : in my samples F. elatior proper is longer than
F. pratensis^ and both have occasionally a trace of awn. Yar. arun-
dinacea has a more acuminate, stiff point. Festuca pratensis has
its palea as a rule somewhat more acute than Lolium perenne, and
the flatter tapering rachilla of the latter is more closely appressed to
the palea. The caryopsis of Festuca also tends to adhere to the
palese.

© ® Paleoi and "seer/" at most 3 — 3'5 mm. long.

= Palea devoid of hairs or keel, notched or
hlunt, and with no trace of awn.
A Palea hyaline, nerves indistinct. Tips
notched or blunt.

Agrostis alba.

There is occasionally a very short basal hair (awn).

Agrostis and Aira will present difficulties to the beginner, not
only on account of their small sizes, but also from the variability as
regards awns, basal hair-tuft, &c. None are of value, and most of
them are weeds.

IX] "seeds" 145

Acp'ostis alba, L. (var. stolonifera).

Palea, enclosing the fruit 1'8 — 2 mm. long, white,
delicate, membranous, with a blunt notched apex and
three (or five) nerves : occasionally there is a fine kneed
basal awn, not projecting.

The glumes may remain attached : the outer has a
serrulate keel, and often a violet hue. No awn. About
2 — 3 mm.

Caryopsis about I'l mm. long, oblong, yellow, corn-
shaped, furrowed, shining through.

A . vulgaris, L., is a variety with slightly smaller
fruits, no awn, and usually three nerves to the palea,
but they cannot be distinguished with certainty by the
"seed." Rachilla obsolete.

The colour of the glumes may vary coiiisiclerably and is some-
times yellow.

The absence of awn, rachilla, and basal hairs distinguishes
Agrostis from Aira.

AA Palea memhranous^ ribbed, tips scarious.

Olyceria aquatica.
G. Jluitans.

Glyceria aquatica, Sm.

Palea strongly 5 — 7 ribbed, obtuse and scarious, about
4 mm. long. Green with a purple cast. Caryopsis dark-
brown, about 2 mm. long.

Inner palea punctate. Rachilla slender and cylindrical.

Glyceria fliiitans, Br., is very similar, but longer
(6 mm.) and more slender ; the palea scabrid with
truncate or ragged tips, and the inner palea not punctate
Yellow. (Fig. 46.)

w. 10

146 CLASSIFICATION OF [CH.

Glycena aquatica and G. fluitans are sweet grasses of value in
water-meadows only. The " seed " is not often met with.

Not only with the Poas, but also with Catahrosa are there
difficulties in determination. Molinia and Koeleria also present
difficulties with Glyceria : the former has fewer and feebler nerves.
DigraphU and Arundo are easily distinguished by the basal hairs.

= = Palea acute and somev:hat compressed and
keeled^ and %dth hairs on the ribs. Tips
nerved.

Poa annua.
P. maritima.
P. distans.
P. rigida.
P. loliacea.
P. bulbosa.
P. alpina.

Their "seeds" are all small, about 2 — 3'5mm. only, and angular,
brown, and present many difficulties (see note, p. 141).

Poa annua, L. (Fig. 43).

Palea 3*5 and caryopsis 2 mm. long, so that the " seed "
is much larger than P. trivialis, and there is no web.
Minutely silky-hairy on the keel, and the ribs are strong
for a Poa,

Poa alpina, L., has the palea five-ribbed with stiffish
hairs below, but no web. Bronzy green-violet. " Seed "
3 — 3-5 mm. long. Caryopsis 1*5 — 2 mm., and slightly
grooved. It is rare in England, and is interesting as
it becomes viviparous in Alpine situations.

(2) Apex of palea distinctly pointed, acuminate
or mncronate, but not giving rise to a true,
long, hristle-like awn.

IX] "seeds" 147

* Palea acuminate — i.e. taper pointed.
+ Not compressed or obviously keeled.

Festuca ovina.
F. sylvatiea.
Cynosurus cristatus

It is doubtful whether these should not be regarded as a^vned :
if so they come near Sardus — see p. 130,

Festuca ovina, L. (Fig. 59).

Palea rounded on the back, narrow, terete-lanceolate
and live-nerved, tip scaberulous and drawn out to a stiff

Fig. 59. Festuca ovina. a, spikelet, x about 3J. b, "seed,"
nat. size and x about 7. c, caryopsis, uat. size and x 7.

scabrid point half as long as the palea, or less. About
3 — 4 mm. long without the tip-point, 4 — do mm. with it.
Rachilla obliquely truncate and concave at its apex.
Caryopsis oblong, somewhat flattened, dark-brown.

The numerous varieties of F. ovina cannot be distinguished by
the " seed " : the allied varieties F. rubra, F. duriuscula, and F. hete-
rophylla, &c. are sometimes more distinctly awned (see p. 172). But
difficulties will be found with the whole group, which needs revision.
This group comprises the grasses so valued on downs and dry hill-
pastures for sheep-feeding.

Festuca sylvatiea, Vill., not a connnon plant, is also with
difiiculty separable (Fig. 51).

10—2

148

CLASSIFICATION OF

[CH.

Cynosurus cristatns, L. (Fig. 60).

Palea canary yellow to light-brown, lanceolate with
rounded back and the mid-rib promi-
nent as a slight keel and margins in-
folded, about 4 mm. long (varies from
3 — 4-5 X 0*5 to 1 mm. broad), scabrid
above, dotted below and acute to
acuminate with a scabrid awn-point,
often curved. Caryopsis 2 — 2*3 mm.,
somewhat flattened. Rachilla short
and smooth, dilated above.

A valuable and easily recognised grass.
Molinia, Holcus and similar impiu'ities are
easily detected : some Fescues are much
more like it ; e.g. F. tenuifoUa (see p. 46) in
which the apex tapers suddenly to a point.
Dactylis should also be compared.

Fig. 60. Cynosurus
cristatus. a, " seed "
and caryopsis, nat.
Bize; & and c," seed"
X about 8. Note the
scabrid and slightly
curved awn-point.
Nobbe. Cf. Fig. 64.

ft Palese compressed or distinctly keeled.

Molinia coerulea.
Koeleria cristata.

Unimportant, except as impurities among other grass " seeds."
Molinia is said to occiu" as such in samples of Cynosurus, Dactylis,
Poa trivialis, Fescues, &c., but it should give little difficulty except
in comparison with Glyceria (see p. 146).

Molinia ccerulea (Moench.) (Fig. 61).

" vSeed " 3 — 4 mm. or more, leather coloured or with a
bluish tinge. Paleae divaricating, the lower keeled and
compressed, and tapering to a sharp point. Rachilla long,
oblique and prominent. Smooth tapering, palea 5 '5, fruit
2 mm. long.

IXJ

" SEEDS

14^d

Koeleria cristata, Pers. (Fig. 62).
Palea 6 mm., keeled, entire, no awn but stiffly tapering,
ribbed, no hairs. Rachilla large. Fruit 4o mm.

Fig. bl. Molinia ccerulea. a,
"seed," nat. size; b and c,
ditto, X about 8; d, the cary-
opsis, nat. size; e, ditto, x about
7. Note the compressed, keeled
and glabrous palea, and the
long slender bone-shaped ra-
chilla. Nobbe.

Fig. 62. luiileria cristata. a,
the "seed" (to the left) and
caryopsis (to the right), nat.
size; h, "seed," x about 7.
The palea is compressed and
keeled, and, like the large
rachilla, glabrous. Nobbe.

** Palea not taper pointed, but mucronate, or two-
toothed, with a sub-terminal point or spine.

Elymus arenarius.
Agropyrum repem.
Dactylis glomerata
Sesleria ccerulea.

Elymus arenarius, L. (Fig. 63).

Fruiting palea lanceolate, 13 — 15 x 3 mm., tough and
stiffly hairy or velvety : 5 — 7 ribs. Rachilla stout, hairy.
Fruit hairy above, 5 —11 mm. x 2-5 x 1*2, somewhat grooved.

150

CLASSIFICATION OF

[CH.

Xo keel. Apex of inner palea bifid, outer miicronate.
Fruit shelled. ,

Easily distinguished from Digraphis ai'undinacea, which has
a basal hair-tuft and very different caryopsis ; less easily from
Agropi/ram and Lolium, except in the velvety yui'face.

Fig. 63. Elymus aren-
arius. a, "seed,"
nat. size; h and c,
the same, x 3. Note
the stiff, velvety, bifid
and mucronate outer
palea, and the large
hairy rachilla. Nobbe.

Fig. 64. Dactj/lis glomerata. a, spikelet
with glumes removed, nat. size; 6,
ditto, X about 6; c and d, " seed," nat.
size (below) and x about 6. The stiff
and slightly curved awn-point is sub-
terminal and arises from between two
teeth. Rachilla dilated above. Nobbe.
Cf. Fig. 60.

Agropyrum repens may have a mucronate awn-point
or not. The small palea 10 — 12, the caryopsis 5 — 6 mm.
(see p. 169 for description).

This troublesome weed (Couch-grass) presents similar difficulties
with Lolium perenne that Agrojji/rum caninum does with Lolium
temulentum—nQQ p. 168. It is moreover extremely variable.

IX J "seeds' 151

Bactylis glomerata, L. (Fig. 64).

Stiff awn-point just below the two teeth of apex of
pale. Rachilla dilated above. Palese 5 — 6 mm. long
exclusive of point, compressed and inflated, ribbed and
ciliate-bristly on keel, the tip incurved. Caryopsis yellow-
brown, ellipsoid, 2 mm.

An important grass, said to be adulterated with Lolmm, Fescues,
Holcus^ MoUnla, Bro7nus^ &c., most of which should be readily
detected. The curved tip is an important distinctive character.
Cynosurus and Festuca arundinacea, F. ovina and F. rubra present
resemblances. The seed is larger than that of Poa.

F. ovina and F. rubra are smaller, rounded dorsally, and have no
keel or cilia : the nerves are less prominent and the rachilla smaller.

Sesleria ccBrulea, Ard.

Palea distinctly toothed at the apex, making it almost
three-lobed and very characteristic ; with awn-point ; live
ribs, serrulate. Fruit grey-yellow, obovate.

It is a mountain- and moor-grass of little value.

B. "Seed" awned— i.e. the investing palea bears, or
tapers into, a distinct bristle or hair at least as
long as itself or nearly so.

{a) Awn not terminal.

(1) Awn stout, either obviously tiuisted and bent
or '^ kneed."
(i) " Seed " consisting of the glumes as well as palese
investing the caryopsis ^.
© Aion bent but not twisted ; glumes free below,
ribbed, and icith stiff short hairs on the keel.
= Awn sub-terminal, shorter than the palea,
^0^^^^- Holcas lanatus.

1 In cases where the '* seed " has fallen from the glumes the sample
will usuaUy show some of the latter lying loose.

152 CLASSIFICATION OF [CH.

"Yorkshire Fog," of little use or importance, except that it is
frequently found as an impurity of other hairy grasses — e.g. Alope-
awrus.

It cannot easily be confounded with any other grass : Antho-
xanthum and Alopecwus, Arrhenatherum, &c. present superficial
resemblances only.

These glumed hairy " seeds " are uncommon and form an easily
recognised type.

I 4

Fig. 65. Holcus lanatiis. a, "seed" — i.e. complete spikelet — and ditto
devoid of glumes, nat. size; b, spikelet, and c the same devoid of
glumes, X 7. The "seed" is here composed of the keeled glumes
enclosing two pairs of paleae and their flowers (c) : the upper of
these is barren and has a hooked sub-terminal awn to its outer palea.
The lower awnless one is fertile. Nobbe.

Holcus lanatiis, L. (Fig. 65).

The "seed" consists of the complete spikelet, separated
below the compressed and acute, keeled glumes; these
have hairs on the keel, and completely enclose the two
flowers and their palese. Palea ribless, white to gi'ey,
shining, obtuse, that of the upper (male) flower with a
sub-terminal short hook-like awn. Total length about
4 — 5 mm. Caryopsis oblong-ovate, grooved. In its
palea about 2 — 3 mm. long and with a few hairs at the
base.

IX]

"seeds" 153

= = Awn dorsal, kneed, longer than the palea.

Holcus mollis, L. (Fig. Q>Q).

Palea 2'5 min., fruit 3'1 mm. long ; glumes with stiff
hairs or serrulse od keel.

The seeds of Holcus often fall from the glumes, but
may bring them away.

Fig. 66, Holcus mollis. Type of "double seed," which really consists
of the entire spikelet [a, nat. size; c a6d d, x 8) comprised of the
two glumes enclosing two pairs of paleae and their enclosures
(6. nat. size; e, x about 8). The lower pair of paleae are devoid
of awns and enclose the caryopsis: the upper pair have stamens
only, and the outer palea has a dorsal kneed awn, not twisted or
hooked. Nobbe.

Holcus is of little use. The two-flow^ered spikelets and peculiar
awns sufficiently distinguish it among the smaller forms. It is said
to occur as an adulterant in " seed " of Alopecurus.

154 CLASSIFICATIOX OF [CH.

0© Ai'm bent and twisted, basal or nearly so;
glumes very hairy.

A Glumes golden brown : one awn straight^
one ^^ kneed"

Anthoxanthum odoratum.

The grass which gives the scent to new-mown hay. The " seed "
IS often impure, containing a continental species A. Fuelii and other
hairy forms.

Fig. 67. Anthoxanthum odoratum. a, " seed " and caryopsis, nat. size;
6, the "seed," and c, caryopsis, x about 7. The "seed" consists
of the inner hairy glumes, each with a dorsal awn — one kneed —
enclosing the paleae and carj^opsis. The outer pair of unawned
glumes has been removed. Nobbe.

Anthoxanthum odo7^atu'm, L. (Fig. 67).

The ODe-flowered spikelet has four hairy glumes, the
outer pair of which are unequal and awnless : the " seed "
consists of the inner pair of golden-brown hairy and
dorsally awned glumes, covering the thin, membranous,
shining, smooth, blunt palese and the caryopsis, to which
the inner palea adheres. Total length, without awns,
about 3 — 4 mm. Palea 1"6 mm. Caryopsis 1*5 mm., brown,
shiny, and easily separating. One awn is short, stift
and straight and inserted above the middle of its glume ;

IX]

SEEDS

155

the other longer and sharply bent, inserted about the
middle.

Hierochloe, a rare northern grass, also comes here.

AA Glumes connate below, hairy on the keels.
Alopecurus pratensis.
A. geniculatus.
A. agrestis.

Alopecurus is very characteristic, and should be carefully
examined as a type. A. pratensis is a valuable grass and said

Fig. 68. Alopecurus pratensis. a, " seed," nat. size, and b, c, ditto, x 8 ;
d, caryopsis, x 7. The "seed" here consists of the two glumes,
connate below and hairy on the keel and ribs, including the
caryopsis enveloped in a single palea with a dorsal awn. Note
remains of stigma in d. Nobbe.

to be often adulterated with the undesirable A. agrestis, -tfolcus, &c.
Arrhenatherum and Avena are easily distinguished by the btisal
hairs, rachilla, &c.

156 CLASSIFICATION OF [CH.

Alopecurus pratensis, L. (Fig. 68).

Inner palea absent. Outer palea 5 mm., caryopsis
8 mm. long, often with remains of the stigma.

The greyish-brown spikelet of Alopecurus easil}' falls
as a whole, included in the glumes ; the palea is loose and
delicate.

Glumes connate below, silky-hairy on keel and ribs all
the way up. The palea has a bent dorsal awn, about 5 mm.
long. ^

Alopecurus genicidatus, L.

Palea 2 mm., fruit 1*3 mm. long.

The glumes hairy on ribs and keel as in J . pratensis :
glumes more obtuse.

Alopecurus agrestis, L.

Palea 6 mm., fruit 3 mm. long.

Glumes only ciliate, on ribs and keel, except at the
base where the hairs are longer.

Keel slightly winged.

Best distinguished from A. pratensis by the glumes, which are
smoother, broader above the middle, harder and with a few basal
hairs.

The species A. fulvus^ A. bulbosus, and A. aljmius are rare.

(ii) " Seed " consisting of the palciE investing the
caryopsis, freed from the glumes.
* Palea at least 14 or 16 mm. long: caryopsis
5 — 7 mm. [Oat type.']
Avena fatua.
A. pratensis.

Avena fatua, L.

Palea parchment-like, lanceolate-terete, acuminate and
bifid at the apex, rounded on the back and with yellow

IX] "seeds" 157

hairs on the lower part. 15 x 3 mm. Awn brown,
twisted and bent, arising from the middle, about 80 mm.
long. Caryopsis 7 mm. long, hairy at the top and
distinctly grooved. Rachilla with fine bristles.

A vena 'pratensis, L.

Palea very similar to A. fatua, apex 2— 4-tootbed or
bifid, rachilla with stiffer hairs. Caryopsis about 5 mm.
long.

Avena pubescens, Huds. is a variety of A. pratensis
found on dry calcareous soils. The caryopsis is very
narrow, and the rachilla long and feathered with hairs.
"Seed" shorter than A. pratensis, 10 — 13 mm., and
darker in colour.

A. fatica is an excellent type of the grasses with dorsal twisted
and bent awns, and easily examined on account of its size. The
student will find difficulties with other species of Avena and
Arrhenathei'um.

Harz says the stiff hairs of Avena bring about the formation of
intestinal concretions (phytobezoars) and are therefore dangerous to
domestic animals.

** Palea not more than 7 — 10 mm. long.
t Caryopsis 4 — 5 mm. long,
Arrhenatherum avenaceum, Beau v. (Fig. 47).
Paleae papery, ribbed. Awn 13 — 15 mm., twisted below ;
palese, with a tuft of hairs below and a ciliate keel, investing
the fruit : the whole being cylindrical, 8 — 10 mm. x 1'5.

Caryopsis 4 — 5 mm. x 1*2, fusiform, pubescent. Ra-
chilla hairy.

The distinctive difference between Avena and Arrhenatherinn is
in the spikelets as a whole. The latter has the lower flower of each
sjnkelet male only. Samples contain the " double seeds," and the
awn of the upper fertile portion is short (see Fig. 69).

158

CLASSIFICATION OF

[CH.

ft Caryopsis not more than 3 mm. long. A hift
of hairs on rachilla and base.

Avena flavescens.

Aira Jlexuosa, distinguished by its nearly basal awn, harder
texture and darker colour of palese, and Dactylis — awnless and with
cui'ved long drawn-out. apex — are found as impurities in foreign
"seed."

Fig. 69. Avena flavescens. c, "seed," nat. size; a and h, ditto, x about

7. The dorsal twisted and kneed awn is very characteristic. Note

also the hairy rachilla. The palea is bifid above— not visible in the
lateral view. Nobbe.

Avena flavescens, L. (Fig. 69).

Yellow. Palea about 5 mm. long, five-ribbed, bifid
at the apex into two long slender teeth, closely investing
the brownish caryopsis, and with a sub-dorsal awn 10 mm.
long with little or no twist, and hairy at the base.
Rachilla fiattened and with white hairs. Caryopsis not

IX] "seeds" 159

much grooved, fusiform, 2 — 3 mm. long, glumes unequal,
somewhat keeled and rough.

(2) Aiun dorsal or basal, fine and hair-like, and
little or 7iot at all tivisted or kneed. ''Seed''
small.

* A pencil of silky hairs on base or rachilla. Palea
bifid at the tij^.

t Basal hairs longer than palea, and obscuring the
awn.

Gala.magrostis Epigeios.

Of little importance, Digraphis has no awn.

Calamagrostis Epigeios, Roth.

Palea about 8 mm. long with toothed apex and very
thin caryopsis 1 mm. A conspicuous tuft of fine silky
hairs, longer than the palea at the base and on the
rachilla.

Awn slender, dorsal, about as long as the palea.

C. stricta, Nutt. and C. strigosa, Hartm, are rare.

ft Basal hairs shorter than palea.

© Awn brown, bearded in the middle, thickened
and lohite above.

Air a canescens.

The student will find considerable difficulties in the various
species of Aira and Agrostis, owing to their small size and variability
as regards awn and basal hair-tufts. All these are weeds, but some
occur as adulterants.

Aira canescens, L.

" Seed " (apart from the aw^n, it is very like Agrostis)
I'D — 2 mm., with a very thin, smooth, keeled, two-nerved

160 CLASSIFICATION OF [CH.

palea, bifid at its apex, tiirough which the yellow caryopsis
shines.

Awn slender, basal, dark-brown, with oblique colourless
hairs above the middle and with a slight swelling above.

The palea has a few hairs on its mid-rib below.

Caryopsis about 1 mm. long.

This grass is somewhat rare in England. The jointed basal awn,
with a minute hair-tuft above the middle, is unique, and readily
distinguishes it when mixed with Agrostis.

© © Aion not bearded or thickened.

= Palea bifid at apex.

Air a caryophyllea.
A. prcecox.

Air a caryophyllea, L.

"Seed" 1-4 — 1'6 mm., comma-shaiDcd and dark-brown.

Palea acute, nerveless, inrolled at edges and with a
dorsal, kneed, very fine, dark twisted awn twice as long as
the palea : the latter with two-toothed apex and a basal
hair-tuft.

A common impurity in commercial seed.

Aira prcecox^ L. is very similar, and cannot be distinguished
with certainty by the " seed," but has a shorter awn and no basal
hairs. Apex of palea two-toothed.

= = Palea jagged or toothed, but not bifid.

Aira flexuosa.
A. ccespitosa.

Aira flexuosa, L. (Fig. 70).

Palea 5 mm. long, four-toothed at the apex, and
caryopsis 2*6 mm. The fine basal awn waved or kneed,
about twice as long as the palea. Fruit with a groove.

IXj

SEEDS

161

Kachilla hairy. Whole "«eed" browner than Avena
flavescena (see p. 158).

Fig. 70. Aira flexnosa. a, "seed," nat. size; c aud d, the same,
X about 7 ; h, portion of fruiting panicle, showing the flexuous
rachis ; e, the caryopsis, nat. size ; /, ditto, x about 7. Note the
basal hairs and twisted awn. Nobbe. Cf. Fig. 44.

An almost worthless grass, en sandy soils, but important as an
impurity in Avena Jlavescens (see note, p. 158).

Aira ccespitosa, L. (Fig. 44).

The palea, about 2*5 mm. long, toothed above, has a

fine straight hair-like basal awn not longer than itself.

Caryopsis 1*3 mm., grooved. Rachilla distinctly hairy.

Easily distinguished when mixed with Foa nemoralis, &c. — e.g.
by the awn, hairs on rachilla, &c. It requires scrutiny in regard to
Agrostis, which also has no awn or basal hairs.

** No basal tuft, or merely a few short microscopic
hairs below. Palea; not bifid above.
Agi'ostis canina.
A. Spica-venti.
A. setacea.

w. 11

1(32 CLASSIFICATION OF [CH.

Agrostis canina, h., is somewhat larger than A. alba.
Palea (only one present, sometimes minute) punctate,
2 mm., with a fine dorsal aw^n a little longer than the
palea. Caryopsis 1*2 mm. Rachilla obsolete.

The awn is usually absent from A. alba and its varieties ; and
when present is so small as to be almost negligible.

A. canina is easily distinguished from Foa by the rachilla in the
latter, and absence of awn. Aira has basal hairs, e^c.

Agrostis setacea, Curt., has the awn basal and just
projecting beyond the pointed glumes, and the palea
very minute, with a few silky hairs below.

Agrostis Spica-venti, L. (Fig. 49).

Palea 2*4 mm. long, with infolded edges and punctate ;
a minute rachilla at its base, and a slender awn, 8 — 9 mm.
or more long, inserted below the bifid tip. Caryopsis
1*5 mm. A few silky hairs at the base of the palea.

{b) Awn terminal or slightly sub-terminal, and
straight, or at least not twisted or " kneed."

(1) Falece so closely adherent to the fruit that
the tertninal awn appeal's to come from
the latter {Barley type]. The three florets
generally coherent.

•••" A^im at least twice the length of the grain.

Hordeum sylvaticum.
H. murinum.

Hordeum sylvaticuni, Huds.

Palea scabrid, ribbed above, awn at least twice as long
as the very narrow grain.

IX] "seeds" 163

Hordeum murinam, L.

Lower palea 9 — 10 mm. long, five-ribbed, lanceolate
and wrapped round and adhering to the fruit (grain),
upper palea also ribbed. The grain about 7 — 8 ram.
X 2 X 12, hardly grooved. Awn about 30 mm. long,
serrulate. Rachilla slightly serrulate.

** Awu not twice the length of the grain,

Hordeivm pratense.
H. maritimum.

Hordeum pratense, Huds.

Spikelet with a reddish tinge ; awn almost smooth,
less than 20 mm. long : not twice the length of the
smooth and obscurely nerved grain.

Hordeum rtiaritimum, With., similar to H. pratense,
but softer and the awn somewhat longer.

The principal features of the Hordeum-gvaiw are the closely
adherent palese and angular fruit, the stiif awn appearing to come
off from it as in Barley. The rachilla remains.

They are all weeds of no use in agriculture, though H. pratense
is not uncommon in good pastures.

(2) Falea investing the caryopsis, often closely,

but not fused with it, and its tip and awn

quite free.

* Awn not strictly terminal but sub-terminal,

or arising from between two teeth or in a

sinus at the apex of the palea.

+ Caryopsis thin, flattened and usually 6 — 10 mm.
long, and the palere hairy.

= Palea inrolled, terete-lanceolate-acvminate, or
linear-lanceolate {barge-shaped). Apical teeth
minute and pointed.

11—2

164

CLASSIFICATION OF

[CH.

A Palea scaherulous or hairy, awn from half to
about its own length.
Bromus erectus.
B. asper.

Bromus erectus, Huds.

Palea with 5 — 7 scaberulous ribs, but not hairy, flat
above, incurved below, so that the inner palea is clearly

Fig. 71. Bromus asper, a barge-
shaped "seed" with terminal
awn, nat. size and x about 5.
Cf. Fig. 50. Stebler.

Fig. 72, Braclnjpodium sylvati-
cum, a barge-shaped "seed"
with terminal awn, natural
size and x about 5. Cf. Fig.
77. Stebler.

IX] " SEEDS ' 165

visible. About 10 — 14 mm. long and narrowing somewhat
suddenly into the smooth stiff awn, shorter than itself.
Indications of a tooth at each side of the base of the awn.
Caryopsis somewhat flattened, thin and long, barge-shaped,
8 — 10 X 1-5 — 2 mm., pointed at both ends, brown, hairy
at the tip with the remains of the stigma, " Seed " often
purplish. Eachilla long and slender.

Must be carefully distinguished from Brachypodium, which has
the palea less inrolled and a stouter racliilla.

Bromus giganteus has a shorter and flatter " seed " and longer
awn.

B7'omus asper, Murr. (Fig. 71).

Palea often reddish, 5 — 7 ribbed and usually roughly
hairy, mid-rib scaberulous, about 15 mm. long, linear-
lanceolate (barge-shaped), the tip more distinctly two-
toothed and tapering more gradually into the smooth
awn, about its own length. Rachilla distinct. Otherwise
resembling B. erectus.

B. giganteus has a shorter "seed" and longer awn.

A A Palea scarcely hairy: aicn up to tidce its
length.

Bromus stenlis.
B. giganteus.

Bromus sterilts, L. (Fig. 50).

Palea nearly smooth, somewhat inrolled, terete-lanceo-
late-acuminate, tough, red-brown, 12 — 15 mm. long, seven-
ribbed, with a long serrulate awn (20 — 30 mm. or more)
practically terminal. Ribs serrate. Caryopsis 9 — 10 mm.
long, flattened, thin. Rachilla distinct, smooth, much
wrapped in, widens upwards and is somewhat flattened.

16tj CLASSIFICATION OF [CH.

The very slender and long " seed " and caryopsis distinguish this
from all but B. erectus, which has a shorter awn. Perhaps the awn
is truly terminal : if so it should go with Festuca Myurus, &c. (see
p. 171). The length varies greatly.

Bromiis giganteus, L.

Palea 7 mm. long and inrolled, the base and rachilla
bristly, indistinctly 5 — 7 nerved, the tip bifid: sub-
terminal awn serrulate, 12 — 15 mm. long.

Caryopsis 4'5 mm. long, flattened, thin, glabrous.
The caryopsis is shorter and more ovoid than in other Bromes.

== = Palea expanded above {coracle-shaped), aion
from sinus between tivo blunt or triangular
teeth.

Bromus arvensis.

Bromus arvensis, var. mollis, L. (Fig. 73).

Palea oblong or obovate, somewhat flattened above
(coracle-shaped), distinctly 5 — 7 ribbed, 8 — 9 mm. long,
not hairy, though the ribs may be ciliate. Awn smooth,
arising from the depression between two teeth or rounded
projections. Caryopsis flattened and thin, 6 x 1"5 mm. ;
apt to fall loose from the palese.

In the variety B. secalinus the awn is usually shorter than the
elliptical palea, and originates in the sinus of a notch (Fig. 74) : in
B. mollis from between two teeth, and is as long as the obovate palea.

Bromus maximus and B. madritensis are both rare.

The broader nerved palete of B. mollis and shorter, fatter
caryopsis, as well as the longer awn distinguish it from B. secalinus
and B. arvensis. In the other Bromes the palea is more inrolled and
the "seed" more slender as a rule. The rachilla is \isually bent
above into a slight kink.

The Bromes are an extremely difficult group. The awn is
inserted between the two teeth of the palea or just below. The
palea smooth or cihate on the nerves or roughly hairy. The fruit is

IX]

" SEEDS

1(J7

flattened in the antero-posterior plane, and usually shines through
the closely investing palea. A rachilla is visible. In Bradoj podium
the caryopsis is less flattened, and the apex tapers into the awn

Fig. 73. Bromus arvemis, var.
mollis, a, "seed," nat. size;
b and c, the same, x 3. d,
caryopsis, x about 3. The awn
originates between two teeth
of the strongly ribbed palea.
Coracle-shaped type. Nobbe.

Fig. 74. Bromtis arvensifi, var.
secaUmis. a, spikelet.. b and
c, " seed," nat. size; d and e,
the same, x G. Nobbe. Cf.
Fig. 73.

without teeth. In Loliiim and Agropyrum the caryopsis is still
more wheat-like and grooved.

All our Bromes are weeds, but some of them are important
adulterants, requiring careful examination.

B. inermis is cultivated, and is a valuable grass. Awn short or
wanting. Palece strongly 5 — 7 ribbed, inner with a marked central
rib, closely adhering to caryopsis.

B. Schraderi is also said to be valuable.

tt Caryopsis not thin and flattened, corn-like,
3-5 — 5 mm. Palea smooth, inflated, boat-like.
Loliinn temidentum.

168 CLASSIFICATION OF [CH.

A weed of cultivation, said to be poisonous to cattle, a possible
explanation of which may be found in a fungus recently discovered
as a very constant inhabitant of the tissues under the seed coats.

Lolium temidentum, L. (Fig. 48).

Palea ovate, 0 — 7-5 x 2-5 mm., papyraceous, inflated,
smooth, the tip dry and emarginate with a slender
sub-terminal awn its own length or longer. It tends to
adhere to the fruit'. Fruit 3'5 — 5 mm. x 2"5 x 15, some-
what depressed. Rachilla large, cylindrical and smooth.

L. j:>ei'enne has no awn, or the merest trace of one. "Seed"
10 — 12 mm. long. Boat-shaped. Palea yellow, three-nerved,
margins papery. Rachilla flat, see p. 143.

** Awn terminal, and \vith no evident teeth at
its base.

= Palea not much inrolled, ovate-lanceolate to
linear-lanceolate, and therefore boat- or barge-
shaped.
A Very hairy.

Brachypodium sylvaticam, Beauv. (Fig. 72).
Palea ribbed and hirsute much like that of Bromus
asper, but straw-coloured, shorter (10 — 12 mm.), linear-
lanceolate, more boat-shaped, and tapering without teeth
into the longer (10 — 13 mm.) hairy awn. Caryopsis
7 — 8 mm., less flattened than in Bromus, with a shallow
groove. Rachilla smooth.

B. pinnatum (p. 171) has a much shorter awn, and is nearly
glabrous.

These grasses are weeds, but are said to occur frequently as
adulterants.

A A (flahrous or nearly so.

++ Palea five-nerved, pubescent.

Agropy^nim caninum.

IX

" SEEDS

109

Ayropyrum repens is also often awncd and may be described here
(see also \). 150).

Agropyrum repens, Beauv. (Fig. 76).
Palea tough, 10 — 12 mm. long, ovate-lanceolate, 3—5
ribbed and smooth; with a short (2 — .3mm.) or long

Fig. 75. Agroinjrum caninum.
Type of boat-shaped "seed"
with sub-terminal awn. a, nat.
size ; h, x about 9, but with
awn cut short. Eachilla thicker
above and hairy ; palea not
toothed. Nobbe. Cf. Fig. 48.

Fig. 76. Agropi/nuu repens.
Awned variety. The awn is
very short and sub-terminal :
the rachilla smooth, a, the
"seed," nut. size; h and c,
ditto, X about 4^. Boat-shaped
"seed" with rounded back.
Nobbe. Cf. Fig. 57.

170

CLASSIFICATION OF

[CH.

(8 mm.) terminal awn or a mere tooth. Rounded back.
Fruit grey-brown, ciliate above, 5 — 6 x 1*4 x 0*7 — 0*9 mm.,
depressed, hardly grooved, adhering to the palea. Rachilla
smooth or not, and narrowed below.

A noxious weed (see p. 150) and hence should be carefully
excluded from "seeds."

A. canimtm, Beauv., has a longer (10 mm. or more)
and rougher awai, and is smaller (about 8 mm.), but
otherwise very similar. Palea smooth except at the
five-nerved apex. Rachilla thickened above, and hairy
(Fig. 75).

Eli/mus differs from Agro'pyrum in its harder velvety palea, no
awn, and its club-like velvety rachilla. It is also larger altogether,
as a rule.

Fig. 77. BrachyiJodium pinnatnm. Type of boat-shaped "seed" with
awn. a, nat. size; b and c, x 7. Nobbe. Of. Fig. 72.

IX] "seeds" 171

■»-+++ Palea seven-rihhed, smooth.

Brachypodiurn pinnatum,

Bracliy podium, pinnatum, L., is similar, but the palea
more open and boat-like and narrows more suddenly
above into the smooth awn which is shorter than itself
(Fig. 77). Length 8 — 9 mm. The caryopsis is, however,
much more slender than in Agi^opyrum.

For distinction from B. sylvaticum., see above. The inner palea
is ciliate and more delicate than in Agropyrum.

= = Palea? rolled round the " seed " which is terete
and tapering gradually into a stiff awn.

A Awn longer than the palea.

Festuca Myurus.

See also Festuca ovina, Cynosurus, &c., p. 147, and Arimdo.

Festuca Myurus, L. (Fig. 80).

"Seed" 5 — 7mm. without the long (10mm.) awn,
tapering and slender (like JSfai^dus), grey or brown. Finely
mamillate upwards. Rachilla small.

A A Awn shorter than palea.

Festuca ovina (var. rubra).

Nai^dus stricta.

Aira Jlexuosa, Molinia and other moor-grasses occur with these
narrow-leafed Fescues, but are easily distinguished : Molinia by
having no awn and being shorter and stouter, and Aira Jlexuosa by
the dorsal awn and basal hairs.

Festuca rubra, L. (Fig. 78).

"Seed" pale brown with rosy tinge, 3 — 5mm. long
without the awn, smooth, or slightly hairy upwards.
Caryopsis 2 — oo mm., compressed, with a shallow broad

172

CLASSIFICATION OF

[CH.

flat furrow on the ventral face and a median long "hilum."
Rachilla cylindrical, smooth, dilated above.

The variety F. heterophylla has narrower and longer

Fig. 78. Festuca ovina, var.

rubra, a, "seed," nat. size;

h and c, ditto, x about 7.

Xobbe. Cf. Fig. 59.

Fig. 79. Festuca ovina, var.
heterophylla. a, spikelet,
X about 3|; b, "seed," and
c, caryopsis, nat. size ; d and
e, " seed," and /, caryopsis,
■ X 7. Nobbe.

"seeds," and a hispid rachilla. Palea 5 — 6 mm.: caryopsis
:3-o— 4-5 mm. (Fig. 79).

Perhaps Bromiis sterilis should also come here (see
p. 165).

With regard to these Fescues the student may note that F. ovina,
var. tenuifoUa, has the smallest (4—5 mm.) and most ovoid "seeds,"
usually golden brown in colour. F. rubra is darker and larger
(5—6 mm.), as is also F, duriuscula (6—7 mm.) : the latter is also

IX

SEEDS

173

narrower, with toothed palca, tai)eriiig suddenly at the base and
more awned. F. heterophylla is much hke F. duriuscula, but the
palea less toothed, and it tapers gradually at the base. The whole
group is very difficult, and needs attention.

;. 80. FestHca Myurus. a,
"seed," nat. size; b and r,
ditto, X about 6. Comi:)are
Fig. 50. Nobbe.

Fig. 81. Nardus stricta. Type
of cylindrical "seed" with
a terminal stiff awn, here
serrulate ; c, "seed," nat. size ;
a and h, ditto, x 8. Compare
Fig. 50. Nobbe.

Nardus stricta, L. (Fig. 81).

Outer palea tough and fused, 10—12 mm. long, narrow,
lanceolate and tapering gradually into the stiff, serrulate,

174. CLASSIFICATION OF " SEEDS " [CII. IX

terminal awn shorter than itself. Inner palea minutely
toothed at the apex and without awn, loosely enclosing
the red-brownish yellow to bluish grey fruit which has no
groove. "Seed " 4 — 6 mm. x 0*6 x 0'5 (without the awn),
more or less triangular in section and serrulate on angles
above.

BIBLIOGRAPHY.

Bentham and Hooker, British Flora^ London, 1896.
Bonnier and Layens, Nouvelle Flore de France, Paris, 1887.
Bruns, Der Grasemhryo in Flora, 1892, vol. lxxvi.
BuRCHARD, Die Unkrautsamen der Klee- und Grasarten, Berlin,
1900.

Darwin, Power of Movement in Plants, London, 1880.
Duval Jouve, in Memoires de VAcad. des Sciences de Montpellier,
1871, vol. vn.

Fream, Elements of Agriculture, London, 1892.

Grob, in Bibliotheca Botanica, H. 36, 1896.

Gu:^RiN, Recherches sur le deoeloppement du Tegument chc. des

Gramine'es in A7in. d. Sc. Nat. 1899.
GuNTZ, Unters. ii. d. anatomische Structur d. Grashliitter, Leipzig,

1886.

Hackel, in Engler's Natiirliche Pflanzenfamilicn, il Th. 2 Abth.

1887.
Harz, Landwirthschaftliche Samenkunde, Berlin, 1885.
HoLZNER, Beitr. zur Kenntn. d. Gerste, Munich, 1888.

Index Kewensis, London, 1893 — 95.

Jackson, A Glossary of Botanic Terms, London, 1900.

Kienitz-Gerloff, Botanik fur Landwirte, Berlin, 1886.

NoBBE, Handbuch der Samenkunde, Berlin, 1876.

176 BIBLIOGRAPHY

Parnell, Bn'tiih Gi'afise.% London, 1845.
Pee-Laby, in Annales des Sc. Natiorelles, 1898, vol. viir,
Percival, Agricidtvral Botany^ London, 1900.
Pfitzer, in Pringsh. Jahrh. f. wiss. Bot. B. vii.

ScHMiD, in i?o^. Centralhl. 1898, B. Lxxvi.

ScHWARZ, ForstUche Botanik, Berlin, 1892.

Schwendener, in Sitzimgsher. d. Akad, Berlin, 1889 and 1890.

Settegast, Die laiidwirths<'hafd. Sdmereien il d. Samenbau,

Leipzig, 1892.
Sinclair, Hortus gramineus Woburnensis, London, 1824.
Sowerby, The Grasses of Great Britain, London, 1861.
Stebler and Schroeter, The Best Forage Plants, London, 1889.
Sutton, Permanent and Temporary Pastures, London, 1886.

Trimen, Article Grasses, in Encyclopredia Britannica, 9th ed.

Van Tieghem, Morphol. de Vemhryon &g. chez les Grarninees in Ann.

des Sc. Nat. 1897.
Vesque, Traite de Botanique Agncole (&c. 1885.

Warming, Lehrh. d. Oekologischen Pflanzengeogr. Berlin, 1896.
Wittmack, Gras- und Kleesamen, Berlin, 1873.

INDEX,

GLOSSARY AND LIST OF SYNONYMS.

Figures in bold type (25) refer to pages whereon the species or
subject is more particularly dealt with; figures in italics (^5) refer to
pages containing illustrations.

Achene, 123

Acicular — bristle-like

Acuminate — tapering to a long

point, 21, 139, 146, 147
Acute — simply pointed, 19, 21
Adaptations, 20, 24, 3G, 37, 70,

124, 125, 132
Adventitious roots, 8, 131
Agriculture, 2, 3

Agropyrum — Wheat-grass, 11, 14,
22, 25, 26, 36, 49, 50, 51, 57, 69,
88, 90, 91, 106, 107, 108, 144,
150, 167, 170, 171; A. canimim,
7, 21, 28, 34, 57, SO, 92, 107,
150, 168, 169, 170; A. junceum
— var. of A. repens, 21, 29, 33, 35,
36, 57, 66, 81, 102, 107; ^1.
repens, 7, 30, 57, 80, 81, 93,
102, 106, 149, 150, 169, 170

Agrostis — Bent-grass, 7, 15, 22, 25,
49, 50, 51, 52, 53, 57, 82, 88, 89,
91, 103, 104, 105, 112, 118,

125, 136, 137, 141, 144, 145,
159, 160, 161 ; A. alba, 7, 11,
13, 14, 28, 29, 32, 33, 34, 51, 52,
69, 92, 104, 144, 145, 162;
A. canina, 7, 11, 20, 2s, 29, 37,
51, 52, 104, 161, 162 ; A.
setaeea, 31, 104, 161, 162 ; A.

W.

Spica-venti, 31, 104, 130, 161,
162 ; A. stolonifcra — var. of A.
alba, 14, 51, 52, 104, 145 ; A.
vulga)-is — var. of A. alba, 29,
51, 52, 66, 104, 145
4z?Y<— Hair-grass, 6, 20, 21, 36, 48,
88, 89, 90, 91, 103, 104, 105,
106, 110, 112, 117, 118, 125,
127, 138, 141, 144, 145, 159,
162 ; A. alpina — var. of .4. cce-
spitosa ; A. canescens, 8, 11, 14.
32, 47, 66, 78, 91, 112, 159;
A. can/ophyllea, 8T 10, 14, 29,
32, 46", 118. 160; A. acspitosa,
6, 11, 14, 22, 23, 25, 28, 33, 37,
41. 47, 48, 63, 65, 68, 69, 77,
104, 106, 117, 128, 160, 161 ;
A. fle.vuom, 7, 11, 14, 29, 33,
34, "46, 68, 70, 71, 79, 118,
158, 160, 161, 171 ; A. viontana
— var. oi A. fte.ruosa ; A. setaeea
— var. of A. fiexuosa; A. prcecox,
8, 10, 29, 30, 32, 47, 91, 112.
160
Air-spaces, 21, 39, 40, 62
Aleurone layer, 121, 122. 123
Alopecurm, 25, 53, 55, 88. 89, 90,
93, lOl, 109, 110, 119, 124, 152.
153, 155; A. alpinus, 31, 101,

12

178

INDEX, GLOSSARY,

156; A. afircstb, 7, 18, 30, 50,
52, 53, lOl, 155, 156; A. hid-
bosiis — var. of A. geniculatus, 8,
9, 156; A. fulvus — var. of A.
geniculatus, 156; A. geniculatus,
7, 9, 11, 14, 15, 28, 2y, 33, 40,
48, 52, 53, lOl, 155, 156 ; A.
pratensis, 7, 11, 13, 14, 18, 28,
32, 49, 50, 51, 52, 55, 82, lOl,
Jo J, 156

Alpine Foxtail — Alopecurus alpinus

Alpine Meadow-grass — Poa alpina

Alpine Poa — Poa alpina

Alps, 36, 37

Ammopliila — Psamma ; A. arundi-
nacea—Psanuna arenaria

Amphicarpuni, 120

Anatomy, 62—71, 95

Andropogon, 4, 27

Andropogonefe, 122

Animal-distribution of seeds, 125

Animals killed by grasses, 127

Annual Beard- grass — Polypogon
mo7upeUensis

Annual grasses, 10, 11, 37, 43, 59,
114

Annual Meadow-grass — Poa annua

Anther, 93, 94, 119

Anthesis — the period of opening of
the flower, 96

Anthoxanthum — Vernal grass, 11,
13, 22, 26, 27, 36, 56, 58, 60, 83,
87, 88, 90, 91, 94, 97, 110, 119,
124, 136, 152, 154 ; A. odoratum,
7, 28, 32, 33, 34, 57, 76, 102,
103, 154 ; A. Puelii, 67, 154

Anti-ligular peg, 41

Apera — Agrostis ; A. Spica-venti —
Agrostis Spica-venti

Apex of leaf, 19, 21, 22

Apogamy, 134

Appressed hairs, 65

Aquatic grasses, 27, 28, 39, 62,
103, 111, 112, 113

Arctic species, 37

Aristida, 36; A. hygrometrica, 127

Arrhenatherum — False Oat, 6, 11,
13, 14, 17, 26, 32, 55, 56, 58, 60,
61, 66, 89, 90, 91, 92, 119, 152,
155, 157 ; A. avenaceum, 6, 8, 25,
28, 33, 34, 56, 66, 77, 93, 106,
129, 157

Arundo—Heed, 11, 14, 19, 20, 37,
40, 68, 69, 90, 91, 93, 103, 125,
130, 131, 139, 146, 171; A.
Donax, 21, 75 ; A, Phragmites,
2, 6, 29, 32, 40, 51, 55, 66, 75,
138

Asperities — minute stiff hairs giving
roughness to the touch, 24, 45,
65, 66, 75, 77, 127

Auricles — ear-like projections at
base of leaf-blade, 22, 133

Aveiia, 5, 15, 21, 23, 47, 54, 56, 88,
89, 90, 91, 92, 95, 104, 106, 116,
117, 125, 127, 138, 155, 157, 158;
A. alpina — var. of A. pratensis ;
A. elatior — Arrhenatherum ave-
naceum; A. fatua, 28, 77, 117,
156, 157 ; A. Jiavescem, 7, 11,
13, 18, 26, 28, 56, 60, 61, 81,
117, 158, 161; A. pratensis,
7, 11, 14, 20, 21, 22, 25, 27, 47,
56, 61, 63, 66, 81, 117, 156,
157 ; A. pubescens — var. of A.
pratensis, 16, 26, 27, 32, 33, 56,
61, 68, 157 ; A. strigosa — var.
of A. fatua

Aveneae, 122

Awn, 91, 92, 95, 99—118, 125,
126, 127, 128, 129, 130, 131,
142, 144, 151, 153, 154, 159,
160, 162, 163, 164, 166, 167, 168,
169, 170, 171, 173

Awned grasses, 92, 99—101, 102,
103, 104, 105, 106, 107, 111,
112, 113, 114, 115, 116, 117,
151—174

Awned Nit-grass — Gastridium len-
digerum

Awnless Brome — Bromus inermis

Awnless grasses, 93, 104, 105,
107, 108, 109, 110, 111, 112,
138-151

Awn-point, 114, 115, 116, 123, 131,
150

Ballast plants, 30

Bamboos, 1, 5, 6, 37, 38, 96, 97, 123

Bambusa, 96

Barge-shaped "seeds," 128, 163,

164, 168
Barley— Hordeum, 120, 132, 133,

163

AND SYNONYMS

179

Barley-type of " seed," 138, 162

Barren Brome — Bromus sterilis

Barren flowers, 86, 89, 90, 99,
100

Basal-awn, 92, 128, 129, 130, 159

Basal hair-tufts, 138, 158, 159,
160, 161

Base of leaf, 18, 19, 20, 22

Bast-sclerenchyma, 70

Bearded Darnel — Lolium temulen-
tum

Bearded Wheat grass — Agropynun
caninum

Besixd-gi&ss—PoIijpogon

Bent-grass — Agrostis

Bent-grass — Agrostis canina

Bermuda grass — Cynodoii Dacty-
Ion

Biennial grasses, 10, 43

Bifid — cleft into two teeth, 95

Bitter-tasting grasses, 58, 59

Blade of leaf, 17, 18, 19, 20, 22,
23, 24, 26

Blue Moor-grass — Sesleria ccerulea

Boat-shaped "seeds," 127, 128,
129, 138, 142, U3, 144, 167,
168, 169, 170

Bcehmer's Phleum — Phleum Boeh-
meri

Brachypodium — False Brome, 11,
14, 20, 60, 70, 88, 90, 107, 108,
109, 165, 167; B. pinnatum, 7,
34, 61, 78, 93, 107, 130, 168,
170, 171; B. sylvaticum, 7, 26,
28, 33, 34, 60, 61, 76, 78, 92,
107, 128, 164, 168, 171

Bracteoles, 95, 96, 97

Bracts, 94, 97

Branching, 6, 11

Branching of inflorescence, 83

Bristle- grass — Setaria

Bristle-leafed Bent-grass — Agrostis
setacea

Bristle-like leaves, 16, 21, 24, 45

Bristle Oat — Avena strigosa

Bristles, 67, 125, 130

Briza — Quaking-grass, 14, 16, 22,
25, 90, 91, 92, 104, 136; B. media,
8, 11, 17, 27, 32, 45, 66. 77,
112, 142; B. minor, 10, 17,
45, 112, 142

Brome — Bromus, 166, 107

Bromus — Brome-grass, 6, 10, 14, 17,
26, 44, 51, 59, 61, 76, 90, 91, 92,
95, 103, 104, 107, 115, 117, 144,
151, 168; B. Alopecurus, 95; B.
arvensis, 7, 8, 11, 27, 30, 32, 43,
44, 76, 108, 115, 128. 166,
167; B. asper, 6, 11, 17, 20, 22,
26, 28, 33, 34, 43, 44, 59, 76,
115, 116, 164, 165, 168; JB.
commutatus — B. racemosus ; B.
diandrus — B. madriteyisis ; B.
erectus, 7, 11, 13, 14, 43, 51,
70, 100, 164, 165, 166; B.
giganteus, 6, 11, 28, 33, 34, 43,
44, 51, 76, 82, 115, 116, 165,
166; B.inermis, 13, 22, 31, 43,
167 ; B. madritensis, 31, 116,
166 ; B. maximus, 31, 116, 166 ;
B. mollis — var. of B. arvensis, 8,

26, 43, 44, 108, 115, 143, 166,
167; B. multijiorus — var. of B.
arvensis ; B. racemosus — var. of
B. arvensis ; B. Schraderi, 167 ;
B. secalinus — var. of ^. arvenns,
115, 166, 167; B. sterilis, 7, 11,

27, 30, 32, 43, 44, 76, 116,
131, 165, 172

Brown Bent — Agrostis canina

Buds, 12

Bulbous Meadov,'-grass — Poa bul-

bosa
Bulbous Poa — Poa bulbosa
Bulbs, 8, 37, 114

Calamagrostis — Small reed, 29, 40,
88, 89, 125, 138; C. Epigeios,
31, 70, 78, 103, 159; C. lanceo-
lata, 31, 66, 103, 138; C. stri-
gosa, 103, 159; C. stricta, 31,
103, 159

Canary grass — Plialaris canari-
eusis

Carpel, 97, 121

Caryopsis — the true fruit of the
grass, 121, 122, 123, 124, 127,
128, 132, 134, 135

Ca^/?>rosa— Whorl-grass, 14, 21, 23,
29, 40, 63, 84, 88, 90, 91, 92, 104,
105, 118, 146; C. aquatica, 12,
25, 31, 73, 112, 142

Cat's-tail grass — Phleum

Cat's-tail type of inflorescence, 100

12 2

180

INDEX, GLOSSARY,

Cells, 65

Cereals, 1

Chali", 85, 134

Chalk-fleeing, 35

Chalk species, 27, 32, 35

C}i(i ma (/ roxtis — 3Ii bora

Chlorophyll, 2, 62, 70, 72, 73, 95

Cinna, 97

Circular shoot sections, 16, 43

Classification according to ana-
tomical characters of leaf, 72 —
82

Classification according to floral
characters, 97, 99—118

Classification according to char-
acters of seed, 135 — 174

Classification according to vegeta-
tive characters, 39 — 61

Classification of seedlings, 133

Claj' species, 32

Cleistogamous— when pollination
and fertihsation are completed
in flowers which do not open,
120

Climbing grasses, 6

Close panicle — an inflorescence in
which the primary branches do
not diverge widely from the
rachis, 110

Cock's-foot — Dactylis glomerata, S3

Cockspur Panicum — Panicum Cms-
qalli

Collar, 58, 123

Colovired nodes, 15

Coloured sheath, 18

Coma, 125

Common Cat's-tail — Phleum pra-
tense

Common Dog's-tail — Cynosurus
cristatus

Common Foxtail — Alopecurus pra-
teiisis

Common Mat-grass — Nardiis stricta

Common Quaking-grass — Briza
media

Common Eeed — Arundo Phrag-
viites

Compact Brome — Bromus madri-
tensis

Composites, 2, 125

Compressed shoots, 15, 16, 40, 41,
48, 53

Conduplicate — folded, 15, 16, 20,
63

Convolute — inrolled, 15, 16, 63

Copses, grasses of, 28, 34

Coracle-shaped "seeds," 128,257,
166, 167

Cord-grass — Spartina stricta

Coriaceous — ^leathery, 21

Corn, 1

Corn-field species, 28

Corn-type of fruit, 136, 138, 167

Corynephorus canescens — Aira ca-
nescens

Cotton-grass — Eriophorum

Couch-grass — Agropyrum repens.
See also Twitch, 150

Creeping Fescue — Festuca rubra

Creeping grasses, 12, 13, 14, 15

Creeping grass-seeds, 127

Creeping Soft-grass — Holcus lana-
tus — Holcus mollis

Creeping stem, 12

Crested Dog's-tail — Cynosurus cris-
tatus

Crested Kceleria — Kceleria cris-
tata

Cross-breeds, 120

Cross-fertilisation, 119, 120

Crtjpsis, 123

Culms, 14, 37, 83

Curved Lepturus — Lepturus in-
curvatus

Cuspidate — ending suddenly in a
short j)oint, 135

Cut-grass — Leersia

Cuticle, 68, 70

Cutinized, cuticularized — impreg-
nated with corky substance, 64

Cylindrical inflorescence, 90

Cylindrical "seed," 173

Cynodon — Dog's-tooth grass, 14,
65, 67, 69, 87, 90, 105 ; C. Dacty-
lon, 15, 31, 72, 137

Cynosurus — Dog's-tail, 14, 18, 25,
49, 50, 52, 81, 88, 89, 90, 93, 103,
130, 148, 151, 171 ; C. cristatus,
7, 11, 13, 23, 28, 32, SO, 80,
108, 147, 148; C, echinatus,
100, 108

Dactylis— Cock's-foot, 11, 13, 14,
16, 20, 26, 41, 63, 83, 88, 89, 90,

AND SYNONYMS

181

91, 93, 103, 148, 158 ; D. glome-
rata. 7, 16, 17, 27, 32, 33, 34,
41, 65, 66, 69, 74, 109, 149,
150, 151

Darnel — LoUiim perenne — Lolimn
temulenttnii

Decumbent Heath-grass — Triodia
decumbens

Dehiscent fruits, 123

Depauperated — starved and con-
sequently dwarfed, 109

Deschampsia ccespitosa — Aira ccb-
spitosa

Deschampsia jiexuosa — Aira Jiex-
uosa

Digitaria — Panicum

Digitate — spread out like fingers,
15

Diqraphis — Eeed-grass, 6, 11, 13,
26, 40, 41, 51, 55, 69, 73, 75,
90, 91, 92, 103, 131, 139, 146, 159;
B. arundinacea, 6, 16, 33, 29,
32, 54, 64, 75, 103, 139, 150

Dimensions of grasses, 6

Dinochloa, 6

Dioecious, unisexual, the male and
female flowers being on separate
plants, 119

Disarticulation of fruits, 124

Dissemination, 125, 127

Distichous — in two ranks on the
axis, 106

Distribution of grasses, 2, 37, 38

Distribution of seeds, 124 — 127

Distribution of sexes, 119

Ditches, grasses of, 28, 29

Dog's-tooth grass — Cynodon Dacty-
lon

Dorsal awn, 92, 112, 116, 130, 159

Double seed — grass "seed" where
the remains of a second flower
come away with the first, 153,
158

Downs, grasses of, 29

Downy Oat — Avena pubescens

Dry leaves, 21

Dry situations, 24, 26, 29

Dry soils, 29, 32

Duration, 10

Dwarfed species, 6

Early Hair-grass — Aira prcecox

Ears, 19, 22, 57, 59

Echinochloa — Panicum

Effects of grasses on soil, 35,
36

Egg-cell, 121

Eleiisine, 123

Elliptical shoot- section, 16, 44

Elymus — Lyme-grass, 6, 13, 14,
21, 22, 25, 36, 48, 57, 63, 65, 69,
79, 90, 92, 102, 170; E. arenarius,
6, 29, 33, 35, 36, 48, 66, 67,
108, 149, 150

Embryo, 121, 131, 133

Embryo-sac, 121

Embryonic bud — plumule, 123

Embryonic roots, 123, 133

Endosperm, 120, 131, 133, 123

Energy stored in leaves, 2, 3

Entire — not cut : with unbroken
outline, 19

Entire sheath, 17

Entire-sheathed grasses, 17, 39,
113, 115

Epidermis, 25, 36, 62—67, 70, 76,
133

Equitant — one folded leaf strad-
dling over another, 39, 41

Eriophoruni, 3

Extra-vaginal shoots, 12

False Oat — Arrhenatheriwi aven-

aceum
Female flowers, 89
Fertile flowers, 86, 89, 90
Fertilisation — the fusion of the
nucleus of the pollen-tube wuth
that of the egg-cell, 121
Fescue— Festuca, 115, 130, 137,

144, 148, 151, 172
Festuca— Fescue, 2, 6, 7, 15, 21, 25,
36, 49, 51, 53, 90, 91, 92, 108, 109,
110, 113, 114, 116, 134, 144, 147',
F.arundi)iacea — va.v.ofF.elatior,
144, 151 ; F. calamaria — F.
sylvatica ; F. duriuscula — var,
of F. ovina, 46, 69, 78, 80, 147,
172, 173; F. elatior, 6, 7, 11,
13, 14, 18, 19, 22, 25, 28, 32, 44,
50, 51, 63, 64, 82, 84, 108, 111,
115, 116, 128, 131, 143, 144;
F. yiyantea — Bromus yif/dnteus ;
F. heterophylla — var. of F. ovina,

182

INDEX, GLOSSARY,

13, 46, G9, 71, 78, 80, 147, 172,
173; F. nnighimis, 31, 92, 111;
F. loUacea—ya.i\ of F. elatior,
90. 108; F. Mi/urus, 8, 10, 14,
19. 20,28,46, 90,91,92, 99, 111,
115, 130, 16(), 171, 173; F.
ovina, 7, 8, 11, 13, 14, 19, 20,
22, 24, 28, 32, 33, 36, 45, 46, 68,
69, 70, 79, 111, 112, 115, 116,
134, 147, 151, 171, 172; F.
pratensis — var. of F. elatior, 7,
19. 24, 49, 63, 64, 84, 111, 143,
144; F. procinubens — Poa pro-
cumhens ; F. rigida — Poa rigida •
F. rubra, var. of F. ovina, 7, 13,

14, 18, 24, 33, 46, 69, 78, 80,
Ul, lol,!!!, 172; F. so bulicola—
F. rubra, 46; F. sciuroides — var.
of F. Myurus, 25, 26, 46 ; F.
sylvatica, 6, 11, 14, 28, 34, 116,
131, 147 ; F. temdfoUa—Y&Y. of
F. ovina, 46, 148, 172; F.
vivipara — var. of F. ovina

Festuceae, 122

Fibichia umbellata — Cynodon Dac-

tylon
Fibrous roots, 8
Fibrous Twitch — Agropyrum cani-

num
Field Brome — Bromus arvensis
Filament, 94

Fine Bent — Agrostis vulgaris
Finger-grass — Panicum glabrum
Fiorin — Agrostis alba
Firing, 35, 38
Flanking lines, 41, 53, 63, 73,

74
Flat leaves, 20, 47, 77
Flat shoots, 15, 16, 20
Flattened Meadow-grass — Poa com-

pressa
Flavour, 27
Fleshy fruits, 123
Floating leaves, 39
Floating Foxtail — Alopecurus geni'

culatm
Floating Meadow-grass — Glyceria

flu i tans
Floating Sweet-grass — Glyceria

flidtans
Floral diagram, 94, 95, 96
Flower, 83, 64, 85, 86, 87, 89, 90,

93, 94, 95, 96, 97, 99, 105, 106,

112
Flowering glume — the outer palea
Flowering stem, 83, 84
Flying Bent — Molinia ccerulea
Folded leaves, 15, 16, 20, 24, 25,

63, 69, 70, 74
Foreign grasses, 30
Forestry, 3

Forest species, 27, 28, 33
Form of lamina, 19, 20
Foxtail grass — Alopecurus
Foxtail type of inflorescence, 9, 88,

100
Fructification — fruiting, 120
Fruit, 119, 123, 125, 126, 129,

134, 136—174
Fruit-coats, 121, 122
Functions of awns, 95, 125, 126,

127
Functions of ears, 19
Functions of leaves, 2
Functions of ligule, 18, 19
Functions of lodicules, 96
Functions of spear, 132
Furrows, 23, 78

Gastridimn — Nit-grass, 90, 91, 101,
103, 105 ; G. lendigerum, 31

Germination, 123, 131—133

Germination of pollen-grain, 120,
121

Giant Fescue — Festuca gigantea

Girders — supporting bands of scle-
renchyma running in the princi-
pal ribs and ridges, 63, 64, 65,
66, 67, 68, 69, 70, 71, 74—80

Glabrous — devoid of hairs, 18, 19,
22, 26, 45, 48, 80, 168

Glaucous — pale sea-green, usually
due to a waxy bloom, 22

Glume, 85, 86, 87, 91, 92, 93, 94,
95, 99—118, 124, 125, 127, 130,
134, 135, 136, 151, 152, 153, 154,
155, 156

Gli/ceria — Sweet-grass, 6, 14, 20,
21, 37, 40, 54, 67, 90, 91, 92, 136,
137, 138, 146, 148 ; G. aquatica,
6, 11, 16, 17, 25, 26, 28, 39,
54, 69, 73, 103, 111, 112, 113,
142, 145 ; G. distans—Poa dis-
tans ; G. fuitans, 6, 11, 16, 17,

AND SYNONYMS

183

25, 28, 32, 39, 40, 54, 64, 66,
69, 73, 111, 113, 128, 145; G.
maritima — Poa viaritima ; G.
procumhens — Poaprocumhcns ; G,
riqida — Poa rigida

Grain, 86, 95, 121, 122, 127, 135

Graminace®, characters, 3, 36, 37

Graminege, see Graminaceae

Grass, origin of the word, 3

Grass carpets, 2, 37

Grasses, identification of, 3, 4

Grazing, 27

Grey Hair-grass — Aira canef^cens

Grooved leaf, 69, 70, 71, 79

Grooved sheath, 18

Gynerium, 89

Habit, 13, 34

Habitats, 27—31

Hair-grass — Aira

Hairs, 18, 19, 21, 24, 26, 62, 64,

66, 67, 91, 125, 130, 131, 138,

139, 144
Hair-tufts, 59, 123, 125, 129, 158
Hairy grasses, 18, 19, 21, 22, 23,

26, 57, 76, 81

Hairy Brome — Bromus asper

Hairy " seeds," 168

Half-shade species, 34

Halophytes, 36

Hard Fescue — Festuca duriuscida

Hard-grass — Lepturus

Hard leaves, 21, 47

Hard Meadow-grass — Poa rigida

Hardy Bamboos, 38

Hare's-tail — Lagurus

Harsh leaves, 21

Haulm, 83

Havers — Aveyia fatua

Hay, 27, 37

Heath False-Brome — Brachy po-
dium pinnatum

Heath- grass — Triodia decumbens

Heath-grasses, 20, 29, 36

Height, 6

Hcleochloa, 123

Herbaceous — of the ordinary soft
texture of herbs, 6, 21, 91

Heterodera, 10

Heterophylly, 71

Heteropogon contortus, 127

Uierochloe — Holy-grass, 20, 27, 66,

73, 91, 92, 105, 155 ; H. borealis,
30, 65

Hill-jDastures, 29

Hispid — covered with stiff and
rather long hairs, 58

Histology, 62—71, 122

Holcus—Soit grass, 8, 22, 26, 27,
56, 89, 90, 91, 93, 106, 119, 125,
148, 151, 152, 153, 155; H.
lanatus, 7, 11, 13, 14, 17, 23, 26,
28, 30, 32, 34, 59, 65, 69, 81,
106, 143, 151, 152 ; H. mollis,
11, 28, 30, 33, 59, 106, 153

Holy-grass — Hierochloe

Hooded leaf-apex, 21

Hook-hairs, 65

Hordeum—Bsivley, 10, 20, 22, 26,
44, 59, 88, 89, 90, 92, 99, 100, 108,
127, 134, 163 ; H. jubatum, 125 ;
H. maritimum, 8, 10, 29, 33, 59,
lOO, 163 ; H. murimim, 8, 10,
14, 21, 30, 50, 59, 76, lOO,
125, 162, 163 ; H. pratense, 7,
11, 14, 21, 22, 28, 58, lOO,
163 ; H. sylvaticum, 7, 11, 14,
28, 34, 44, 58, 59, lOO, 105,
162

Humus species, 33, 35

Hybrids, 120

Hydrophytes — plants requiring
much water, and therefore aquatic
or semi-aquatic, 37

Hygrophilous species — hydrophy-
tes, 70

Imperfect — rudimentary or stami-

nate, 105
Inconspicuously awned grasses, 93
Indicator-plants, 31, 32, 34
Inflorescence, 5, 9, 12, 15, 83,

86—91, 97, 99, 102, 103, 105,

106, 109— 118, 119
Infolding of leaves, 20, 23, 25, 62,

63, 64
Inrolling of leaves, 20, 23, 25, 46,

62, 63, 64, 65, 66, 67, 69, 75,

78, 79, 80
Intercellular spaces, 37
Interuode, 8, 17
Intra-vaginal shoots, 12, 13
Introduced grasses, 30
Involute— rolled inwards, 20, 47

184

INDEX, GLOSSARY,

Irritability of seedlings, 132
Italian Eye-grass — Lolium italicum

Keel, 18, 33, 26, 63, 68, 69, 91,
113, 127, UO, 144, 146, 147, 148,
149, 151

Keeled grasses, 26, 74

Knappia — Mibora

Kneed awns, 129, 130, 151, 153,
154, 158

Kneed stem, 9

Knot-gras s — Polygonu m

Kceleria, 11, 14,' 19, 20, 25, 26,

90, 91, 92, 101, 103, 110, 141, 146,
149; K. cristata, 8, 29, 32, 66,
81, 109, 148, 149

Lacunae— air-spaces, 70, 73
L(/^//r»5— Hare's-tail, 76, 88, 90,

92, 100, 101, 109 ; L. ovatiis, 31
Lamina — the blade of the leaf,

63—71, 95
Lanceolate — narrow and tapering

at both ends, 163
Lanceolate-acuminate — lanceolate,

but the upper end drawn out to

a long point, 163
Large grasses, 6
Lawns, 10, 37
Lax — loose, the spikelets on slender

branches some distance apart,

110, 117
Layed shoots, 15
Leaf, 17—27, 39—61, 95, 133
Leaf anatomy, 62—71, 72—82
Leaf-apex, 21
Leaf-base, 10, 22, 40
Leaf-blade — Lamina
Leaf characters, 4, 20 — 27
Leaf-margin, 22, 44, 66
Leaf- section, 16, 20, 62—72
Leaf- stalk — Petiole
Leaf-surface, 22, 65, 66, 67
Least Quaking-grass — Briza minor
Leathery leaves, 21
Let'r.s/r(— Cut-grass, 67, 70, 77, 90,

91, 92, 105, 120; L. oryzoides, 30,
66, 137

Leguminosse, 3

Lepturus, 87, 90, 99; L.fili for mis—

L, incurvatus ; L. incurvatus^

31

Ligule, 18, 19, 45, 46, 51, 95, 113,

133
Limestone species, 32
Linear — at least five times as long

as broad, with parallel straight

sides, 19
Linear -acuminate — linear, but

tapering to a long point at the

apex, 19
Linear-acute — linear, but pointed

at the apex, 39
Linear - lanceolate — linear, but

tapering at both ends, 19, 20,

163, 168
Linear- oblong — oblong, but drawn

out so that the sides are parallel

for some distance, 16
Local grasses, 30, 31
Lodicules, 86, 87, 95, 96, 97
Lo/n/?7i— Eye-grass, 13, 14, 18, 22,

25, 49, 50, 53, 57, 59, 82, 88, 90,

91, 107, 108, 109, 144, 151, 167;

L. italicum, 7, 11, 28, 31, 49;

L.perenne, 8, 11, 16, 19, 20, 28,

30, 32, 49, 81, 82, 93, 107,

128, 131, 142, 143, 144, 150,

168; L. temulentnm, 8, 10, 30,

49, 50, 82, 92, 107, 129, 130,

142, 150, 167, 168
Loose Panic-grass — Panicum Cms-

gain
Lygeum, 36
Lyme-grass — Elymus

Maize, 1, 89, 120

Male flowers, 89, 90, 119

Manna-croup — Glyceria Jiuitans

Many-flowered spikelets, 90

Margin of leaf, 21, 22, 66

Marginal asperities, 22

Maritime grasses, 29

Marram — Psa mma

Marsh Bent — Ayrostis alba

Marsh Foxtail — Alopecurus geni-

culatus
Marsh grasses, 28, 29
Mat-grass — Psamma arenaria
Maydese, 122
Meadows, 1

Meadow Barley — Hordeum pratense
Meadow Fescue — Festuca elatior —

Festuca pratensis

AND SYNONYMS

185

Meadow Foxtail — Alopecunis pra-

t ens is
Meadow-grass — Poa pratensis, 83
Meadow grasses, 27, 28, 37, 113
Meadow Soft-grass — Holcus lana-

tus
Mechanical tissues — tissues com-
posed of hard-walled cells (scle-

renchyma) serving for support,

62, 63, 64, 68
Medium grasses, 7
Melica—Melick, 11, 14, 16, 19, 20,

23, 25, 26, 34, 63, 90, 91, 92, 110,

136, 137, 142; 31. ciliata, 32;

iM. nutans, 7, 17, 33, 41, 78,

104, 105, 137; M. uniflora, 7,

17, 28, 33, 40, 41, 78, 104, 105,

137
Melocanna, 123
Membranous ligule, 19
Mesophytes — plants adapted to

ordinary conditions of moisture,

37
Mibora, 68, 87, 89 ; 31. verna, 31,

74, 99
Micropyle, 121

Microscopic characters, 62, 122
Mid-rib, 15, 20, 21, 25, 63, 67, 68,

74
MZm»i— Millet-grass, 6, 11, 14, 20,

22, 27, 34, 89, 91, 92, 137; 31.

eifusmi, 6, 28, 33, 103, 136
Millet — Paiiicum, 135
Mill et-grass — 3Ii Hum
Millet-seed type, 127, 135
Moist soils, 26, 32
3Iolima, 8, 14, 19, 20, 40, 60, 77,

90, 91, 92, 146, 148, 151, 171 ; 31.

cicrulea, 7, 26, 29, 32, 33, 36, 37,

40, 59, llO, 148, 149
Monocotyledons, 97, 134
Monoecious — male and female

flow^ers on the same plant, 119
Moor-grass — Sesleria
Moor-grasses, 8, 20, 29, 37
Moor Mat-grass — Nardus stricta^

83
Morphology of flower, 95, 96, 97
Morphology of spikelet, 94
Motor-cells, 25, 41, 62, 63, 64,

65, 66, 67, 69, 70, 71, 73, 74, 75,

76, 77, 78, 79, 80

Mountain Melick — 3Ielica mitans
Movements of awns, 125, 126, 127
Movements of seedlings, 132
Mucronate — with a short point
suddenly springing from a
rounded apex, 22, 138, 139, 146,
149, 150
3IyosoUs, 3

Naked fruits, 136

Nardus, 8, 9, 11, 14, 20, 21, 64, 65,
66, 67, 70, 80, 83, 87, 88, 89, 90,
91, 93, 94, 130, 146, 171; N.
stricta, 8, 9, 29, 33, 36, 46, 64,
69, 70, 99,. 171, 173, 174

Narrow-leafed Osit— Avena pra-
tensis

Narrow Small-reed — Calamagrostis
stricta

Naviculate — Boat - shaped, but
pointed at both ends, 16

Nematode worms, 10

Nerves — minute veins on pale£B,
113, 115, 128, 140, 144, 168

Nodes, 6, 8, 12, 14, 15

Nodules, 10

Northern Holy-grass — H ierochloe
borealis

Nucellus — the body of the ovule or
young seed, 122

Nuclei, 121

Numbers of grasses, 2

Oat— Avena, 85, 89, 133
Oat-type of " seed," 156
Obsolete — so much reduced as to

be practically absent, 19, 45, 48,

115, 116
Obtuse — rounded off and blunt at

the apex, 19, 91
Odours, 27
Offsets, 12
Olyra, 6

One-flowered spikelets, 89
One-glumed Fescue — Fcstuca uni-

glumis
Open panicle — one where the

primary branches stand off at

right angles from the rachis,

112
Orange spiked Foxtail — Alopecurus

full us

186

INDEX, GLOSSARY,

Orchids, 2

Ovary, 86, 87, 89, 95, 96, 97, 119,
121

Ovate-acute — egg-shaped in out-
line, but the free narrow end
pointed, 61

Ovate-lanceolate— ovate, but taper-
ing above, 168

Pale— Palea, 86, 89

Palea, 84, 85, 86, 87, 92, 93, 95,

ge^ 97, 99—118, 119, 120, 124,

125, 127, 128, 129, 130, 131, 134,

135—174
Pampas-grass, 1
Panic-grass — Pan icum
Panicle, 5, 12, 87, 88, 90, 91, 103,

105, 109—118
Panicum, 4, 19, 67, 69, 72, 87, 90,

92, 101, 105, 109, 124, 135, 136,

137, 142; P. Crus-galli, 137; P.

glaucum, 30 ; P. iMcatum, 21 ; P.

sanguinale, 30 ; P. verticillatum,

30
Papillae — protruding cells not long

enough to be termed hairs, 64,

67
Pappus, 125

Parallel venation, 21, 22
Parenchyma — ordinary soft cel-
lular tissue of herbaceous parts,

64, 65
Partial inflorescence, 86
Pasture, 1, 10

Pasture-grasses, 27, 28, 37
Perennial Beard-grass — Polypogon

littoralis
Perennial grasses, 10, 11, 40, 48,

58, 114
Perennial Oat — Avena pratensis
Perennial Oat-grass — Avena pra-
tensis
Perfect flowers, 89, 90, 99, 100,

105, 106
Perianth — the floral coverings, 96
Pericarp — the coats of the true

fruit, 121, 122
Petiole, 5, 17

Phalaris — Canary grass, 88, 101,
109, 136 ; P. arundinacea — Di-
grapliis arundinacea ; P. canari-
ensis, 81, 139

Phleum, 66, 88, 89, 90, 91, 93, 102,
109, 110, 136, 137, 142 ; P. aljn-
num, SO, 102 ; P. arenarium, 7, 10.
29, 37, 55, 102, 136; P. asperum,
31, 55, 102, 136; P. Boehmen,
8, 31, 55, 102, 136; P. nodosum—
var. of P. pratense ; P. pliala-
roides — P. Boehmeri ; P. pratense,
7, 8, 11, 13, 25, 28, 32, 55, 70,
76, 102, 128, 135

Phloem, 67

Phragmites communis — Arundo
Phragmites

Physiognomy, 36, 37

Piercing of soil, 132

Pilose — with scattered, rather long
soft hairs, 59

Plaited vernation, 21

Plantago, 3

Plicate — plaited

Plume-like inflorescence, 91, 103

Plumule, 121, 123, 132, 133

Poa, 2, 15, 20, 21, 23, 25, 26, 47, 54,
61, 74, 83, 84, 88, 89, 90, 91, 92,
103, 104, 109, 110, 113, 114, 115,
116, 118, 127, 131, 140, 141, 144,
146, 151, 162 ; P. aljuna, 8, 11,

13, 14, 16, 17, 31, 44, 54, 63,
114, 134, 146 ; P. ayinua, 8, 10,

14, 16, 30, 34, 42, 53, 54, 63,
68, 74, 75, 114, 127, 141, 146;
P. dquatica — Glyceria aquatica;
P. bulbosa, 8, 11, 14, 29, 54, 69,
111, 114, 146; P. compressa, 8,
11, 14, 15, 16, 30, 32, 42, 53, 54,
63, 69, 74, 111, 114, 139, 140;
P. distans, 29, 30, 114, 146 ; P.
fertilis — P. serotina, 45 ; P.
fluitans — Glyceria Jluitans ; P.

laxa, 31, 134; P. loliacea, 31,
108, 114, 146; P. maritima, 8,
11, 14, 16, 20, 22, 26, 29, 47,
54, 111, 114, 146; P. nemoralis,
7, 11, 14, 15, 28, 34, 45, 54, 63,
74, 75, 113, 114, 139, 140, 141.
161 ; P. pratensis, 7, 11, 13, 14,
16, 17, 27, 32, 33, 41, 42, 44,
45, 54, 55, 67, 75, 113, 114,
139, 140, 141; P. procumbens,
31, 111, 114 ; P. rigida, 10, 14,
30, 111, 114, 146; P. stricta—
var. of P. alpina, 134 ; P. trivi-

AND SYNONYMS

187

alis, 7, 11, 13, 14, 16, 17, 18, 27,
32, 42, 44, 45, 54, 74, 90, 112,
113, 139, 140, 141, 146, 148

Pollen, 93, 94, 119

Pollen-grain, 120, 121

Pollen-tube, i-?C, 121

Pollination, 93, 119, 120, 121

Polygonum, 3

Polypogon — Beard-grass, 69, 90, 91,
92, iOO, 101, 109 ; P. littoralis,
31 ; P. vionspeliensis, 31

Ponds, grasses of, 28, 29

Popular names, 6

Potassium salts, 32

Prairies, 1, 36, 38

Prickle-hairs, 66

Primary root, 123, 131

Procumbent Meadow-grass — Poa
procumbens

Protandrous — when the pollen is
mature and shed before the
stigma of the same flower is
ready for pollination, 119

Proterogynous — when the stigma
is receptive before the pollen of
the same flower is mature, 119

Psamma, 4, 11, 13, 14, 21, 25, 36,
48, 79, 81, 89, 90, 92, 95, 138;
P. arenaria, 7, 29, 33, 35, 36,
48, 70, 79, 102, 138, 139

Pubescence — hairiness, 26

Pungent — spine-like, 22

Purple-flowered Small-reed — Caki'
magrostis lanceolata

Purple-stalked CsiVs-tSiil—Phleum
Bcehmeri

Purple-veined sheaths, 18

Quadrangular shoot-section, 16, 40
Quake-grass — Briza
Quaking-grass — Bi-iza media

Eacemous — like a raceme, 105
Eachilla, 85, 123, 124, 128, 129,

131, 137, 138, 142, 143, 144,

149, 150, 164, 167, 169, 170, 172
Eachis, 9, 85, 88, 106, 107
Eadiele, 121, 123
Eare grasses, 6, 30, 31, 89, 90,

91, 92
Eat's-tail Fescue — Festuca Myu-

rus

Eed-sheathed grasses, 18, 49, 59

Eeed, 2

Eeed Canary grass — Digraph is

anmdinacea
Eeed Fescue — Festuca sylvatica
Eeed-grass, 1, 6
Eeed Meadow • grass — Glyceria

aquatica
Eeed Sweet-grass — Glyceria aqua-
tica
Eeflexed leaves, 16
Eellexed Meadow-grass — Poa dis-

tans
Ehizomes, 10, 11, 35, 36, 37
Ehomboidal shoot-section, 16, 42
Eib-grass — Plantago
Eibbon - grass — iJigraphis arun-

dinacea
Eibs — the more opaque veins due

to the larger vascular-bundles,

22, 25, 62, 91, 127
Eice, 1

Eidgeless grasses, 25
Eidges, 18, 21, 22, 23, 24, 25, 26,

47, 51, 53, 54, 65, 66, 67, 68, 69,

71, 73, 77, 78, 79, 80, 91
Eiver-banks, 28, 29
Eoad-sides, 29
Eolled leaves, 15, 16, 20, 24, 25,

63
Eolling of leaves, 24, 25, 36
Eoot-cap, 121
Eoots, 8, 12, 35, 121, 123, 131, 132,

133
Eough Cock's-foot — Dactylis glo-

merata
Eough Meadow-grass — Poa trivialis
Eough Phleum — Phleum asperum
Eough-stalked Meadow-grass — Poa

trivialis
Eound shoots, 15, 16, 42, 50, 57
Euderal grasses, 29, 32, 34, 35
Eudimentary flowers, 89, 90, 105
Eunners, 12, 13, 14
Eushes, 4, 33
Eushy Wheat-grass — Agropyrum

junceum
'Rye—Secale, 120, 132, 133
Eye Brome — Bromus secalinus
Eye-grass — Lolium perenne

Salt species, 33

188

INDEX, GLOSSARY,

Saud-binders, 13, 35, 36, 48, 102,

107, 108
Sand Cat's-tail — Phleum aren-

arium
Sand dunes, 35, 36
Sand species, .29, 32, 36
Sandy situations, 8, 29, 33
Savannahs, 1, 38
Scaberulous— slightly rough to the

touch, 22, 45, 164
Scabrid — rough to the touch, 22,

47, 54
Scarious — as if scorched by fire,

92, 145
Scents, 27
Sclerenchyma — mechanical tissue,

62, 65, 66, 67, 68, 69, 70, 71, 74,

75, 76, 79, 80
Sclerochloa — Poa
Sclerochloa maritima — Poa niari-

tima ; S. procumbens — Poa pro-

cumbens ; S. rigida — Poa rigida
Scorpion-grass — Myosotis
Scutellum, 121, 123
Sea Barley — Hordeum maritimum
Sea Cafs-tail — Phleum arenarium
Sea-grass — Zostera
Sea Hard-grass — Lepturus incur-

vatiis
Sea Lyme-grass — Ehjmus arenariiis
Sea Mat-grass — Psamma arenaria
Sea Mat- weed — Psamma arenaria
Sea Meadow-grass — Poa maritima
Sea Poa — Poa maritima
Sea Reed — Psamma arenaria
Sea-side grasses, 27, 29
Secondary roots, 121, 123, 131,

183
Secund — turned to one side, 9, 89,

108, 109, 114
Sedges, 3, 4, 33, 35, 121
Seed — strictly the contents of the

caryopsis (fruit), but in practice

the fruit and its adherent paleae

etc. (chaff) are termed "seed,"

119, 120, 121, 123, 124, 125, 127,

12.S, 129, 130, 131, 134, 135—

174
Seed-coats, 121, 122
Seedhngs, 132, 133
Semi-aquatic species, 28, 29
Separation of fruits, 124

Serrula? — minute tooth-like asperi-
ties, 22, 91, 173
Sesleria — Moor-grass, 22, 25, 63,

64, 68, 90, 91, 93, 101 ; S. carulea,

17, 42, 67, 108, 149, 151
Sessile — sitting directly on an axis

without an intervening stalk, 87,

99, 107
Setaceous— bristle-like, 16, 19, 20,

21, 24, 45, 111, 113
Setaria — Panicum
Sexual organs, 134
Shade action of grasses, 35
Shade-grasses, 20, 28, 33, 34, 70
Shapes of caryopsis, 127
Shapes of leaves, 4, 19, 20
Shapes of shoot, 16
Sharp-edged shoots, 16
Sheath, 5, 8, 12, 15, 16, 17, 18, 19,

20, 22, 51, 95, 133
Sheep's Fescue — Festuca ovitia
Shelving sheath-margin, 22
Shoot, 10, 12, 15, 16, 123
Sieglingia decumbens — Triodia de-

cumhens
Siliceous — impregnated with flint —

silex, 64, 65, 66
Silky Bent-grass — Agrostis Spica-

venti
Silvery Hair-grass — Aira caryo-

phijllea
Single - husked Fescue — Festuca

uniglumis
Slender Foxtail — Alopecurus agres-

lis
Small grasses, 7
Small Reed — Galamagrostis
Smooth Brome — Brovius racemosus
Sociable plants, 36
Sod, 37

Sodium chloride, 33
Soft Brome — Bromus mollis
Soft-grass — Holcus
Soft Holcus — Holcus mollis
Soil formation, 36
Soil protection, 36
Solid leaves, 46
Solid stems, 4
Sour soils, 33
Spartina — Cord-grass, 69, 87, 90,

99, 105 ; S. stricta, 27, 31, 78
Spear, 123, 132

AND SYNONYMS

189

Spikate inflorescence, 99, 106
Spike, 9, 87, 88, 90, 99, 100, 101,

102, 106, 108
Spiked Fescue — Festuca loliacea
Spikelet, 9, 84, 85, 86, 87, 88, 89,

90, 93. 94, 95, 97, 99—118,

119, 120, 123, 124
Spike-like panicle, 9, 88, 90, 102
Spinescent leaf, 22
Sjjutifex, 125

Split' sheath, 5, 17, 18, 19
Split-sheathed grasses, 17, 18, 19,

45, 50
Sporobolus, 123, 134
Squirrel-tail grass — Hordeum viari-

timum
Stamen, 86, 87, 89, 93, 94, 95, 96,

97, 102, 103, 119
Staminate — a flower with stamens

and no ovary, 100, 105, 106
Starch, 120, 121, 122
Stem, 4, 6, 8
Steppes, 1, 36, 38
Stigma — stigmatic plumes, 86, 87,

93, 94, 96, 97, 119, 120, 121
Stipa, 36, 96, 126; S. capillata,

125; S. pennata, 32, 125; *S'.

spartea, 125
Stolon, 10, 12, 35, 114
Stoloniferous grasses, 8, 13, 14, 15
Stomata, 25, 36, 62, 64, 65, 07, 70,

73, 77, 80, 95
Strand-plants, 36
Stringy roots, 8
Striped grass — Digrapliis arundi-

nacea
Struggle for existence, 2, 37, 38
Style, 94, 97, 99
Sub-acute — hardly pointed, 142
Sub- sessile — very shortly stalked,

so as to be all but sessile, 99, 106
Sub-terminal awn, 95, 115, 129,

130, 150, 151, 152, 162, 163—168,

169
Subulate — awl-shaped : stouter than

setaceous, 19, 20, 21, 70, 71, 79
Sugar, 120, 121, 122
Sugar-cane, 1
Sun-plants, 36
Sweet-tasting grasses, 39
Sweet Vernal grass — Anthoxanthum

odoratum

Sympodium, 11

Tall Brome — Bromus giganteu>i

Tall Fescue — Festuca elatior

Tapering leaves, 21

Tastes, 27

Temperate species, 2

Terete — cylindrical and gradually
tapering, 6, 54, 163, 171

Terminal awn, 92, 111, 115, 110,
126, 130, 162, 168—174, 173

Texture of leaf, 21

Three-flowered spikelets, 90

Timothy — Phleum pratense

Tomentose — softly hairy, 59

Transpiration, 20

Transverse sections of leaves, 16,
23, 24, 63, 64

Transverse section of shoot, 15, 16

Triodia — Heath-grass, 11, 14, 19,
25, 26, 90, 91, 103, 139 ; T. de-
cumhens, 8, 29, 34, llO, 123

Trisetum Jlavescens — Avena fla-
vescens

Triticum — Wheat ; T. acutwn — T.
laxum ; T. junceum — Agropyruni
junceum; T. laxum — Agropyrum
laxum ; T. pungens — T. laxum ;
T. repens — Agropyrum repens

Tropical species. 1, 2

Truncate, 92, 142

Tuber, 8

Tufted grasses, 13, 14

Tufted Hair-grass — Aira ccespitosa

Tufted inflorescences, 90, 99, 102,
103, 109

Tufts, 5, 9, 12, 13, 37

Tumble-weeds, 125

Turgescence — the distension of cells
with water which they have ab-
sorbed, 63

Tussocks, 13

Twisted awns, 116, 125, 126, 129,
130, 151, 154, 158

Twisting of seedling leaves, 133

Twitch — certain persistent weeds
belonging to the genera Agro-
pyrum, Agrostis, Holcus, etc. :
see Couch-grass, 52, 57, 59

Two-flowered spikelets, 90

U-shaped leaf-sections, 20

190

IXDEX, GLOSSARY, AND SYNONYMS

Uniola, 97

Upright Brome — Bromus erectiis.

Also B. madritensis
Uses of grasses, 1, 2

V-shaped leaf-sections, 20, 53, 73
Vagabond grasses, 29, 32, 84
Variability, 26
Vascular bundles, 21, 22, 62, 63,

64, 65, 66, 67, 68, 69, 70, 71, 75,

76, 78, 80, 81
Vascular-bundle sheath, 68, 95,

12:i
Vegetative organs, 4
Veins, 18, 21, 22, 68, 76, 91
Venation, 21, 62, 67, 68
Vermin, 35

Vernal grass — Anthoxanthum, 83
Vernation— folding of the leaves in

bud, 21
Versatile — hung loosely so as to

turn freely, 94
Vessels, 67

Violet-brown sheath, 18
Viviparous grasses, 112, 114, 134
Vidpia 2Iyurus~Festuca Myurm ;

V. uniglumis — Festuca uniglumis

Wall Barley — Hordenm murimim
Wall Fescue — Festuca Mijurus
Walls, grasses of, 29
Waste-places, 29
Water-storing tissues, 36, 70
Water Whorl-grass — Catabrosa

aquatica
Wavy Hair-grass — Aira Jiexuosa
Wavy Meadow-grass — Poa laxa
Wax", 36, 70

Web — minute tufted soft hairs at
the base of the caryopsis, 113,
114, 127, 131, 138, 139, 140,
141

Weeds, 27, 28, 29, 35

Wheat— Triticum, 1, 120, 127, 132,
133

Wheat-grass — Agropyriim

Whorl-grass — Catabrosa

Wild Oat — Avena fatua, 117

Wind-borne seeds, 125, 126

Wings, 125, 142

Wood Barley — Hordeum sylvaticum

WoodFalse-Brome — Brachy podium
sylvaticum

Wood Meadow-grass — Poa nemo-
rails

Wood Melick — Melica uiiifiora

Wood Foa — Poa nemoralis

Wood-species, 28, 33

Woolly Holcus — Holcus lanatus

Xenia — cases where the direct
influence of the pollen is evident
on the seed resulting from its
action, 120

Xerophilous — of the nature of a
xerophyte, 70

Xerophytes — plants adapted to dry
situations, 24, 25, 36, 37, 38, 68,
70

Xylem, 67

Yellow Oat-grass — Avena flavescens
Yellow- sheathed grasses, 18
Yorkshire Fog — Holcus lanatus, 152

Zoster a, 3

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