Ligule

“ The leaf-sheaths are shorter than the internodes, flat, compressed, glabrous, with a few hairs or not at the mouth and with membranous margins; the uppermost sheath is spathiform enclosing the inflorescence when young. The ligule consists of only a thin ridge of short hairs densely arranged. Nodes are glabrous and dark-ringed, and with fan-like spreading equitant leaf-sheaths and leaves more especially when rooting. ”

“ 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. ”

“ 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 of52 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. ”

“ 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. ”

“ 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. ”

“ 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.
59
✲✲ Annual, with thin dry 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. ”

“ As a rule it is split down its whole length, thus differing from that of Cyperaceae which is almost invariably (Eriospora is an exception) a complete tube; in some grasses, however (species of Poa, Bromus and others) , the edges are united. The sheaths are much dilated in Alopecurus vaginatus and in a species of Potamochloa, in the latter, an East Indian aquatic grass, serving as floats. At the summit of the sheath, above the origin of the blade, is the ligule, a usually membranous process of small size (occasionally reaching 1 in. in length) erect and pressed around the culm. ”

“ Turn back the blade slightly and notice at this point a little strap, the ligule (Fig. 98) , on the upper surface of the leaf-blade. Notice the variation in the size and shape of the ligules of different kinds of grass.
Pull the haulm until it gives way, and draw the broken part out of the leaf-sheaths. Chew the end, and notice the taste of sugar. Cut across haulms of various ages. The young haulms are solid; the old ones are hollow except at the nodes, where there is a horizontal shelf. Notice this also in a bamboo cane, which is the haulm of a large tropical grass. ”

“ Both foliage leaves and sporophylls are characterised by the possession of a ligule, a structure which may present the appearance of a somewhat rectangular plate (fig. 130, 4, l, and fig. 131, E–G, l) or assume a fan-shaped form with a lobed or papillate margin. The base, composed of large cells, is sunk in the tissue of the leaf close to its insertion on the stem (fig. 131, E, l) and enclosed by a well-marked parenchymatous sheath. The sheath is separated from the vascular bundle of the leaf by one or more layers of cells, and in some species these become transformed into short tracheids. ”

“ The plants present considerable uniformity in general habit, consisting of a short, unbranched stem, bearing the closely-crowded awl-shaped leaves, which in the larger species attain the length of a foot. Each leaf bears a ligule resembling that of Selaginella in structure and position. The stem is monostelic, the centre of the stele being occupied by a mass of short tracheides; but little can be said as to the primary structure of the central cylinder, which appears to be reduced. ”

“ 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. ”

“ While recognising a general resemblance to the sporophylls of Isoetes, certain differences are obvious: there is no ligule in the fossil leaves nor are there any distinct traces of vascular strands such as occur in the leaves of recent species. The form of the sporangium, more elongated than in the majority of recent forms, is compared by Saporta with that in a south European species Isoetes setacea Spr. ”

“ 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. ”

“ The flowers of sheep’s fescue, however, bear short awns.
The meadow grasses much resemble the fescues in general appearance, but the panicles (Fig. 103) are rather more tree-like—the stalks of the spikelets spreading more horizontally—and the flowers are never awned. The various species can be distinguished by their ligules; for example, the ligule of the smooth-stalked meadow grass (Fig. 103) is blunt, while that of the rough-stalked species is long and pointed. The annual meadow grass is a weed to be found almost everywhere. ”

“ Branches stout, spreading, densely clothed with white tomentum, as are the leaves beneath and branches of the inflorescence. Leaves large, irregularly lobed or sinuate. Heads small, very numerous, crowded in large much-branched terminal panicles, heterogamous, obscurely radiate. Involucre narrow; bracts in 1 series, linear, scarious, shining, usually with minute subulate scales at the base. Receptacle small, foveolate. Florets of the circumference female, irregularly lobed or 2-lipped; outer lobe or ligule broad, inner small, narrow, revolute. ”

“ The student should examine the ligule of every grass he studies.
The haulm, or flowering branch, is for some time short and solid, and its nodes are so close together that the sheath of a lower leaf may overlap several upper leaves. The haulm is thus protected from the [Pg 128] rough weather of the early spring. In the meantime, the flowers have been developing at its upper end. When they are almost ready to open, the haulm begins to grow very rapidly ”

“ Ligulate Corolla. The ligulate or Strap-shaped corolla mainly belongs to the family of Compositæ, in which numerous small flowers are gathered into a head, within an involucre that imitates a calyx. It is best exemplified in the Dandelion and in Chiccory (Fig. 266) . Each one of these straps or Ligules, looking like so many petals, is the corolla of a distinct flower: the base is a short tube, which opens out into the ligule: the five minute teeth at the end indicate the number of constituent petals. ”

“ Cauline-leaves smaller and narrower, sessile, clothed with thin white tomentum on both surfaces. Flowering-stem stout, 2–6 ft. high; raceme of 15–30 heads or more. Heads subglobose, discoid, 1–11⁄2 in. diam., purple; involucral bracts ovate-lanceolate, margins ciliate. Ray-florets with a very short and inconspicuous 2–3-fid ligule. Achenes silky-strigose. Pappus-hairs slightly thickened at the tips.—Handb. N.Z. Fl. 129; Kirk in Trans. ”

“ 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 lines6. ”

“ It is said to be poisonous to cattle and horses.
2. B. Rangiora, Buch. in Trans. N.Z. Inst. xiv. (1882) 357.—Very similar to the preceding, but rather smaller, seldom more than 12 or 14 ft. high, with stouter branches and larger leaves. Leaves 6–15 in. long including the petiole, more coriaceous and glossy, sometimes unequal at the base; petiole longer and stouter, 3–5 in. long. Involucral bracts purplish, hardly shining. Female florets with the outer ligule entire.—Kirk, Students' Fl. 336.
North and South Islands: Shores of Cook Strait, Buchanan! Kirk; Westport, Dr. Gaze! ”

“ Heads solitary, sessile, terminating the branches, 1⁄3 in. diam.; involucral bracts 8–10, linear-oblong, obtuse, coriaceous, tomentose, the inner with broad scarious margins. Florets 12–20; ray-florets 4–6, with a broad and short revolute ligule; disc-florets broadly campanulate, deeply 5-lobed. Achenes linear, grooved, glabrous, expanded into a cup-shaped border at the tip. Pappus-hairs white, rigid, scabrid.—Kirk, Students' Fl. 351.
South Island: Not uncommon in mountain districts from Nelson to northwest Otago. 2000–4000 ft. January–February.
A singular species, quite unlike any other. ”

“ Kirk, Students Fl. 256.
Kermadec Islands: Abundant, T. F. C., Miss Shakespear! Wild Heliotrope.
2. LAGENOPHORA, Cass.
Small perennial herbs. Leaves often all radical. Scapes slender, unbranched. Heads solitary, small, heterogaraous. Involucre short, almost hemispherical; bracts in about two rows, with dry or scarious margins. Receptacle convex, naked. Ray-florets in 1–3 series, female, fertile, ligulate or rarely short and tubular; ligule usually white. Disc-florets numerous, hermaphrodite, tubular, with a broad 5-toothed limb. Anthers obtuse at the base. ”

“ Here in Lombardy there is absolutely no farm, however small, without its rows of Mulberry, Poplar, Walnut, Cherry, &c., overshadowing its canals, brooks, roads, &c., and traversing its fields in all directions. The Vine is very generally trained on a low tree, like one of our Plum or small Cherry trees, so that, viewed at a distance or a point near the ground, the country would seem one vast forest, with an undergrowth mainly of Wheat and Indian Corn. Potatoes, Barley, Rye, &c., are grown, but none of them extensively, nor is much of the soil devoted to Grass. ”

“ We have already been through Ghilan with its almost temperate climate in the lowlands, but damp in the northern portion, where fever is rampant, but where, at the same time, luxuriant vegetation with thick forests, grass in abundance, paddy fields for the extensive cultivation of rice, olive-groves, vineyards, cotton, wheat, tobacco, sugar-cane, fruit and all kinds of vegetables nourish ”

“ Special manures of any kind may fail to produce crops, where this essential requisite to good farming is neglected. Guano, in our opinion, should always be followed by crops of clover, grass, peas, or some crop that will shade the earth, and can be turned under with the plow, to keep up the necessary supply of nitrogenous food for cereal crops.
The effect of Lime and Salt upon land is to dissolve the inert portions of organic matters in the soil, so that plants can suck up their substance into their own composition. Both are highly beneficial, but insufficient to add permanent fertility. ”