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.+
_Glyceria fluitans_ (Br.). Floating sweet grass. Somewhat 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. Especially 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 large air-cavities; ligule
short. Leaf-base with a brown triangle. Margins and keel rather rough.
These two species of _Glyceria_ are distinguished by their
shoot-sections and the ridges of the leaves of _G. fluitans_: they
often occur in the same ditch.
They cannot readily be confused with others on account of their
aquatic habit, and the characters given. The only other aquatic
or semi-aquatic species are forms of _Catabrosa_, _Digraphis_,
_Arundo_, _Alopecurus geniculatus_, _Molinia cærulea_ and the rare
_Calamagrostis_.
The ligule and flat shoots with closed sheaths alone suffice to
distinguish it from the round and split sheathed _Arundo Phragmites_;
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 different.
_Alopecurus geniculatus_, 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.+
(α) 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. Ridges below, but not above.
_Melica nutans_, L. (Mountain Melick). Ligule longer, and without the
awl-shaped peg. Only in Scotland and W. of England.
Both are shade grasses of no agricultural value.
_M. uniflora_, with its quadrangular shoots and anti-ligular 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 quick-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. Prominent obtuse ligule,
torn above. Lamina long, rough, acute, with white lines if held up, and
serrulate edges. No flanking lines[6]. No stolons (Fig. 6).
There is a cultivated variety of _Dactylis_ with broad opaque
white stripes down the leaves: these are totally different
from the translucent white stripes seen on holding the wild
form, or _Aira cæspitosa_, up to the light. Another cultivated
“ribbon-grass”--_Digraphis_--has _round_ shoots, _split_ sheaths, and
a different habit, and the same applies 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 _naviculate_,--the keel is far less prominent, and
the ligule shorter. Moreover _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 1/8 to 1/2 down.
Leaves tend to remain conduplicate. Margins serrulate with teeth
extremely short and directed forwards.
(ii) _Shoots compressed but narrow: the section almost
rhomboid with rounded edges._
_Poa trivialis_, L. (Rough-stalked Meadow-grass). Conspicuous in deep
rich pastures and orchards, preferring slight shade and rich soil.
Valuable pasture and hay grass.
Rootstock 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 cærulea_, Ard. (Blue Moor-grass), of our northern limestone
hills, has narrow, flat, glaucous blue, stiff, mucronate leaves, with
scabrid apex. Ligule ciliate.
_Poa trivialis_ is most likely to be confounded with other Poas,
especially _P. annua_ and _P. pratensis_, since they both have thin
leaves and flat shoots; but _P. annua_ 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
rhomboidal--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, and the shoot-sections more linear-oblong or elliptical.
(β) Sections of sheathed leaves rounded, circular or oval,
there being no prominent keels.
(1) Section of sheathed leaves circular or nearly so, the shoots
being only slightly compressed.
* _Perennial._
_Bromus inermis_ (Awnless Brome).
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, ridges inconspicuous: 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 waysides, &c.
The Bromes are extremely variable 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-glabrous 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 giganteus_ 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 above.
No hair on surface of leaves or sheaths.
✲ _Margins of leaves smooth and even. Blades without ridges,
a keel and flanking lines, acute, base rounded. Ligule 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.
4-5 veins on each side of the median one.
_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 leaves
and longer ligule, introduced into cultivation.
✲✲ _Margins of leaves scaberulous with descending hairs.
Very low flat ridges. Sheath smooth._
_Briza media_, L. (Quaking Grass). A weed in meadows, indicating poor
soil--e.g. moor-lands 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.
II. SHEATHS SPLIT, AT LEAST SOME DISTANCE DOWN.
+A. Glabrous--i.e. with no obvious hairs[7].+
(_a_) Grasses with setaceous or bristle-like leaves;--i.e. the
lamina of the lower leaves remains permanently folded instead
of opening out flat.
(1) Ligule obsolete, auricled at the junction of blade and sheath.
_Festuca ovina_ (Sheep’s Fescue). Densely tufted perennial. Leaves
hard, glabrous and often glaucous, with 5-7 ridges if forcibly
unrolled, ears short, stiff and erect. Branches in permanent sheaths.
Chiefly useful as pastures on downs and dry chalk-soils. Several
varieties are recognised 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.
Myurus_, L. (var. _sciuroides_, Roth.).
The chief varieties of _F. ovina_ are Hard Fescue (_F. duriuscula_,
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 red 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. tenuifolia_ 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.
(α) _Bristle-like (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 flexuosa_, 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).
(β) _Leaves bristle-like, but distinctly due to inrolling
of edges._
_Aira caryophyllea_, L. (Silvery Hair-grass), is scabrid. A weed, with
very slight foliage.
_A. præcox_, 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.
(γ) _Leaves narrow and more or less involute, and subulate
upwards, but easily unrolled, and apt to become flatter
as they age._
_Avena pratensis_, L. (Perennial Oat). Leaves rather thin, dry, harsh,
ridgeless, with flanking lines and a keel[8]; 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 _Avena_ and _Poa_ see pp. 44,
54 and 60.
(_b_) 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 usually glabrous._
_Aira cæspitosa_, 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, with 5-6 white lines between, if viewed by transmitted
light. Wet meadows.
_A. cæspitosa_ cannot easily be mistaken for any other species.
_Alopecurus geniculatus_ is also a moisture-loving grass with
strongly ridged leaves, but the interspaces are far less
translucent and the whole habit is different.
All the other species of _Aira_ have involute and setaceous leaves,
and even _A. cæspitosa_ is apt to roll in its leaves in mountain
varieties, but they are easily flattened out, and show the ridges.
_Psamma 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 _Elymus_,
as it is not eared, and the ridges and ligule are very different.
(ii) _Leaves not specially rigid and hard, and often thin;
glabrous, or shining below. Ridges less evident._
* _Ligule very short or obsolete; blade firm but not hard,
glabrous or nearly so, and shining below. Sheath often
coloured red or yellow at the base._
† _Sections of sheathed leaves narrow, oblong, owing to
compression of shoots. Sheath nearly entire._
_Lolium perenne_, L. (Perennial Rye-grass). Very valuable
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 conduplicate 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. temulentum_, 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_, _Alopecurus
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 surface 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 different 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 _Lolium_, 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.
With regard to _Agrostis_, there is no colour in the sheath, the
ligule is longer and pointed, and the leaves drier and thinner than
in _Lolium_, and harsher on both surfaces. _Agrostis_ has also no
ears.
_Alopecurus pratensis_ has much broader and flatter ridges than
_Lolium_ and a longer ligule, 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.
†† _Sections rounded--elliptical or nearly circular.
Sheath distinctly split, 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 between if held up and examined with a lens. Ligule obsolete
(Figs. 12 and 17).
_Arundo Phragmites_, L. (Common Reed). A large aquatic, reed-like
creeping grass, with broad leaves (3/4 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 resemblances
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.
_Alopecurus 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 brown. Leaves
thin and rough, at least at the base. Ridges not
very prominent, but numerous and distinct._
_Agrostis stolonifera_, L. (Fiorin). Stolons, with numerous 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 _A. alba_, 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,
rough 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.
_Cynosurus_ 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, entire. Leaves numerous. Blades long, dark green,
succulent 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. 50), 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 inconspicuous
ones.
* _No trace of ridges, and the mid-ribs not prominent, but the
leaves show median lines flanked by finer ones when held up.
Blades thin and narrow. Somewhat keeled._
(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 naviculate 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.
(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 bulbosa_, 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, except the aquatic ones (_Glyceria_) and _P. maritima_,
have glabrous ribless blades with the median lines, and slight keel.
_P. pratensis_, _P. alpina_ and _P. trivialis_ (Fig. 8) have
entire sheaths (as have _Glyceria fluitans_, _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. fluitans_ have netted sheaths.
_Poa annua_ is annual, and _P. bulbosa_ 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
bulbosa_ has drier leaves than usual, but its leaves are devoid of
ridges.
** _Ridges can be detected, but are slight and not distinct.
Margins scabrid, at least at the base._
† _Leaves firm, flat, linear, acuminate, not narrowed
below. Glabrous. Ligule membranous._
_Digraphis arundinacea_, Trin. (Reed-grass). Sheathed leaves round
in section; blades convolute, tapering above, 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 Phragmites_ is easily
distinguished by the ligule (see p. 51), and the other aquatic
grasses are quite different (see p. 39).
_Phleum 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, flat and glabrous, but rough at the edges, with
descending teeth. Ridges low and flat. Sheaths smooth: leaves
conduplicate. Ligule long. Sandy coasts, &c. A weed.
_Phleum asperum_, Jacq. and P. _Bœhmeri_, 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
more grooved and dark below, and the ridges more distinct and flat.
It is relatively well rooted and is stoloniferous.
_Arrhenatherum avenaceum_, Beauv. (False Oat-grass). Loose tufts with
short stolons, or bulbous below. Leaves few, narrow, thin, dry, rough,
with very low flat 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. Ridges
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_, _Anthoxanthum_,
_Molinia_ and _Avena_, 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. flavescens_ in its much broader and coarser
hairy leaves, and the ligule; and _A. pubescens_ in pubescence and
flat-shoots and ligule.
†† _Leaves very thin, blade tapering below. Keel
prominent, but no ridges above. 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.
+B. Leaves or sheaths, or both, distinctly hairy.+
(α) Leaf-blades eared at the base.
(_a_) Ears sharply pointed. Leaves convolute, and sections
of shoots round. Ligule short and inconspicuous.
_Agropyrum repens_, Beauv. (Couch-grass). A troublesome 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 stiffer and more glaucous, the leaves
more ribbed, involute and pointed--e.g. _A. junceum_, 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 _Lolium_ (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_.
(_b_) Base of blade with inconspicuous rounded ears. Leaves
convolute. Ligule conspicuous.
_Anthoxanthum odoratum_, L. (Sweet Vernal-grass). Compact tuft. Common
in pastures and hay, but it only 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.
_Anthoxanthum_ 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 obvious ridges, and smooth
sheaths, &c.
_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. Ridges 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.
_Hordeum 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.
✲✲ _Annual, with thin dry leaves_.
_Hordeum 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. maritimum_, With. is a sea-side form, smaller and more glaucous.
Sheaths hairy.
(β) 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 somewhat 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 _H. 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
differences between the species are given above. _H. 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 _Lolium_ see p. 49. _H.
sylvaticum_ and _Bromus asper_ (p. 44).
** No conspicuously red-veined sheaths.
† Ligule absent, or a tuft of hairs.
_Molinia cærulea_, Mœnch. (Purple Molinia). Tussocks, with tough
stringy roots. Leaves narrowed below, and tapering above to a long
point, ridges obsolete; very thin 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 _Anthoxanthum_
(see p. 57), _Arrhenatherum_ (see p. 56) or _Brachypodium_.
_Brachypodium sylvaticum_ is distinguished by habitat, its broad
leaves, membranous ligule, fibrous roots, &c.
_Kœleria cristata_, Pers. (Crested Kœleria). 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 decumbens_, 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 glabrum_, Gaud., _P. viride_, _L._ and _P.
Crus-galli_, L. introduced in the S.E. counties also come here.
†† _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).
_Avena pubescens_, Huds. (Downy Oat-grass). A variety of _A.
pratensis_ (see p. 47), but less densely tufted, and the leaves flat
and pubescent, and especially the sheaths very pubescent. Ligule
ovate-acute. Shoots flat. Dry districts, and a weed.
_Avena flavescens_ is not easily confounded with any other grass if
well grown. All the Poas otherwise like it are glabrous, and without
the ridges. The same applies to _A. pubescens_.
_Arrhenatherum_ 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). Rather 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.