Other formats

    TEI XML file   ePub eBook file  

Connect

    mail icontwitter iconBlogspot iconrss icon

Manual of the New Zealand Flora.

17. Agrostis, Linn

page 862

17. Agrostis, Linn.

Annual or perennial grasses, of very various habit. Leaves usually flat, sometimes setaceous, often flaccid; ligules membranous. Spikelets small, 1-flowered, arranged in effuse or contracted panicles with capillary whorled branches; rhachilla disarticulating above the 2 outer glumes, not produced beyond the flower. Glumes 3; 2 outer equal or subequal, empty, keeled, acute, not awned, usually 1-nerved; 3rd or flowering glume membranous or hyaline, glabrous or hairy, usually truncate, 5-nerved or rarely 3-nerved, with a dorsal awn or unawned, callus glabrous or with a few minute hairs. Palea usually short, often minute or wanting, thin and delicate, hyaline, 2-nerved or nerveless. Lodicules 2. Stamens 3. Styles very short, distinct; stigmas plumose. Grain oblong, free within the flowering glume.

Species about 100, found in all parts of the world, but most abundant in temperate regions, and penetrating as far into the arctic and antarctic zones as any other grasses. Of the 7 species admitted in this work, one is generally distributed in high southern latitudes, two or possibly three are found in Australia, the remainder are endemic.

* Awn of flowering glume distinctly exserted beyond the empty glumes.
Culms 3–18 in. Panicle contracted, 1–4 in. Spikelets ⅙ in. long; pedicels almost hispid 1. A. magellanica.
** Awn of flowering glume often wanting; when present not exceeding the empty glumes.
Minute, softly pulvinate, seldom more than 1 in. high. Panicle usually sunk among the leaves 2. A. muscosa.
Slender, strict, densely tufted, 2–9 in. Panicle narrow, almost spike-like, ½–2 in. long 3. A. Muelleri.
Tufted, 4–18 in.; innovation-shoots intravaginal, without leafless scales at the base. Panicle 2–5 in., contracted, rather dense; branches numerous. Spikelets 1/10–⅛ in., empty glumes scabrid on the keel 4. A. Dyeri.
Laxly tufted, 6–18 in.; innovation - shoots extravaginal, with leafless scales at the base. Panicle 2–6 in., lax; branches in whorls of 3–5. Spikelets ⅛ in., empty glumes smooth 5. A. Petriei.
Weak, very slender, 6–18 in. Panicle 2–6 in., lax and spreading; branches few, capillary, trichotomously divided. Spikelets minute, 1/15 in. 6. A. parviflora.
Laxly tufted, very slender, 6–15 in. Panicle linear, 1½–4 in. by 1/10–⅙ in.; branches short, erect. Spikelets 1/12–1/10 in., pale, shining 7. A. tenella.

Two common European species, A. vulgaris (Red-top) and A. alba (Fiorin), are copiously naturalised in most parts of the colony. They come nearer to A. Dyeri than to any other of the indigenous species, but differ in the creeping rootstocks, laxer panicles, and in the florets having a well-developed palea. Descriptions of them will be found in any British Flora.

1.A. magellanica, Lam. Ill. i. 160.—Culms tufted, very variable in size, 3–18 in. high, erect or shortly decumbent at the base, page 863stout or slender, quite glabrous, leafy. Leaves numerous, shorter than the culms, 1/12–⅛ in. broad, involute, striate, scaberulous on the margins and veins; sheaths long, contracted at the mouth, deeply grooved, pale; ligules oblong, membranous, truncate at the apex, lacerate. Panicle 1–4 in. long, ¼–¾ in. broad, contracted, linear-oblong, rather dense, erect or inclined; rhachis stout, scabrid; branches numerous, whorled, erect, scaberulous. Spikelets ⅙ in. long, light-green or purplish; pedicels usually shorter than the spikelets, scabrid, thickened at the tips. Two outer glumes subequal, lanceolate, acuminate, ciliate or almost hispid along the keel, sides seaberulous; 3rd or flowering glume ½ the length of the 2nd or rather shorter, membranous, glabrous, truncate at the apex and more or less evidently 4-cuspidate, awn from half-way down the back, straight or flexuous or slightly recurved, usually longer than the spikelet. Palea very short, hardly exceeding the ovary, sometimes wanting.—Hook. f. in Phil. Trans, clxviii. (1879) 21. A. antarctica, Hook. f. Fl. Antarct. ii. 374, t. 132; Handb. N.Z. Fl. 327. A. multicaulis, Hook. f. Fl. Antarct. i. 95.

South Island: Otago—Head of Clinton Valley, near Lake Te Anau, Petrie! Auckland and Campbell Islands: Sir J. D. Hooker, Kirk! Antipodes Island: Kirk! Macquarie Island: A. Hamilton.

Also found in Chili, Fuegia, the Falkland Islands, Kerguelen Island, Marion and Heard Islands. Sir J. D. Hooker, in his memoir on the flora of Kerguelen Island (Phil. Trans. Vol. clxviii.) has reduced both A. antarctica and A. multicaulis to A. magellanica, Lam. Professor Hackel concurs in this, remarking that A. antarctica only differs from the typical A. magellanica in the less-pointed outer glumes, and that A. multicaulis is only a dwarfed state, not separable as a distinct variety.

2.A. muscosa, T. Kirk in Trans. N.Z. Inst. xiii. (1881) 385.—Minute, very densely tufted, forming small rounded cushion-like patches 1–2 in. diam., and less than 1 in. high. Culms densely packed, much branched at the base, leafy throughout. Leaves longer or shorter than the culms, pale glaucous-green; blades spreading, flaccid, involute, almost capillary; sheaths shorter or longer than the blades, lax, whitish, membranous, grooved; ligules long, subulate. Panicle very short and dense, often concealed among the leaves, contracted into a close rounded head ⅛–⅙ in. diam., usually many-spiculate, but in depauperated states the spikelets may be reduced to 2–6, or in large states the panicle may be lengthened to ¼–⅓ in.; branches short, sparsely hairy. Spikelets about 1/12 in. long, pale-green. Two outer glumes subequal, ovate-lanceolate, acute, with a green, scabrid keel and thin hyaline margins;. 3rd or flowering glume about ¼ shorter, ovate-oblong, truncate, 5-nerved, awn wanting. Palea wanting. Grain broadly oblong.—A. Spencei, Kirk in Trans. N.Z. Inst. xxix. (1897) 539 (name only). A. æmula var. spathacea, Berggr. in Minneskr. Fisiog. Sallsk. Lund. (1877) 32, t. 7, f. 41–47. page 864

North Island: Omatangi, near Lake Taupo, Berggren! Lake Rotoaira, Kirk! Mount Egmont, T. F. C.; Tararua Ranges, T. P. Arnold! South Island: Nelson—Mount Owen, T. F. C. Canterbury—Broken River Basin, Enys! Kirk! T. F. C.; Mackenzie Plains, T. F. C. Otago—Not uncommon in the eastern and southern portions of the province, Petrie! Kirk! Altitudinal range usually from 1500 to 4500 ft., but descending to sea-level in Southland.

3.A. Muelleri, Benth. Fl. Austral. vii. 576.—Culms compactly tufted, slender, strict, erect, smooth, 1–2-noded, the nodes near the base of the culm, 2–9 in. high. Leaves crowded near the base of the culms and usually much shorter than them, very narrow, often filiform, strict, erect, involute, smooth and glabrous; sheaths long, grooved, glabrous; ligules scarious, narrow-oblong. Panicle very narrow, almost spike-like, ½–2 in. long, erect, purplish or pale-green; rhachis smooth or obscurely scabrid; branches in fascicles of 2–5, unequal, short, erect, capillary, scabrid. Spikelets about 1/10 in. long. Two outer glumes slightly unequal, oblong-lanceolate, acute, green or purplish, usually scabrid or ciliate on the keel, but sometimes glabrous, margins thin and hyaline; 3rd or flowering glume about ⅓ shorter, thin and membranous, truncate, minutely denticulate, smooth, faintly 5-nerved, awn usually absent but sometimes present from the middle of the back. Palea wanting. Grain oblong.—A. gelida, F. Muell. in Trans. Vict. Inst. (1855) 43 (not of Trin.). A. canina var. Hook. f. Handb. N.Z. Fl. 328; Buch N.Z. Grasses, t. 20, f. A. (?) A. subulata, Hook. f. Fl. Antarct. i. 95, t. 53.

Var. paludosa, Hack. MS.—Culms 3-noded, the uppermost node higher up the culm than in the type. Panicle broader and laxer. Spikelets straw-coloured.

North Island: Ruahine Mountains, Colenso, A. Hamilton! South Island: Common in mountain districts throughout. Var. paludosa: Swamps by the Broken River, Kirk! Tasman Valley, T. F. C. 2500–5500 ft. Also in Australia.

Very closely allied to A. Dyeri, from which it only differs in its smaller size and narrow panicle. Var. paludosa has a very distinct appearance, and I had placed it as a separate species, but Professor Hackel considers that it is only entitled to the rank of a variety.

4.A. Dyeri, Petrie in Trans. N.Z. Inst. xxii. (1890) 441.—Perennial; innovation-shoots intravaginal, not clothed at the base with leafless scales. Culms tufted, 4–18 in. high, slender, erect or geniculate at the base, glabrous, 2–3-noded, the upper node considerably below the culm. Leaves shorter than the culms, 1/12–⅕ in. broad, flat or convolute when dry, striate, scaberulous on the margins and both surfaces; sheaths terete, grooved, glabrous, the upper long; ligules oblong, obtuse, membranous, lacerate. Panicle elongated, usually from 2 to 5 in. long, but shorter in depauperated forms, erect, usually more or less contracted, rarely open, green or brownish-green; rhachis slender, scaberulous above; branches in rather distant fascicles placed alternately on opposite sides of the page 865rhachis, strict, erect, capillary, scaberulous, simple or branched from the base or above; pedicels longer or shorter than the spikelets. Spikelets 1/10–⅛ in. long. Two outer glumes subequal, lanceolate, acute, 1–3-nerved, scabrid on the keel; 3rd or flowering glume about ⅓ shorter than the 2nd, oblong, truncate, minutely 4-toothed, awnless. Palea wanting. Anthers small.—A. canina, Hook. f. Fl. Nov. Zel. i. 296; Handb. N.Z. Fl. 328; Buch. N.Z. Grasses, t. 19 (not of Linn.). A. parviflora, Buch. N.Z. Grasses, t. 20c (not of R. Br.).

Var. aristata, Hack. MS.—Flowering glume awned. Other characters as in the type.

Var. delicatior, Hack. MS.—More slender. Panicle broader, much more lax. Spikelets ⅓ smaller. Flowering glume awned.

North and South Islands: Mountain districts from the East Cape, Taupo, and Mount Egmont southwards, abundant. 1000–5000 ft.

Sir J. D. Hooker referred this plant, both in the Flora and in the Handbook, to the northern A. canina, Linn., and no doubt it is closely allied to that species. But Professor Hackel informs me that it does not exactly match any form of A. canina, and in his opinion must be treated as a distinct species, differing from A. canina in the innovation-shoots being always intravaginal, in the more scabrid leaves, in the narrower and more contracted panicle, and in the rather larger spikelets. It usually constitutes a large proportion of the subalpine pastures in elevated districts in both Islands.

5.A. Petriei, Hack. in Trans. N.Z. Inst. xxxv. (1903) 379.—Perennial; innovation-shoots extravaginal, clothed at the base with leafless scales gradually increasing in size. Culms tufted, slender, erect, 6–18 in. high, glabrous, 3–5-noded, upper node almost at the middle of the culm. Leaves 2–5 in. long, 1/15–1/12 in. broad, linear, acute, flat or convolute when dry, glaucous, scabrid on the margins and both surfaces; sheaths terete, glabrous; ligules long, oblong, obtuse, denticulate. Panicle 2–6 in. long, oblong, open, lax-flowered; rhachis smooth; branches in whorls of 3–5, capillary, scaberulous, again branched; pedicels hardly thickened at the tips, about equal in length to the spikelets. Spikelets linear-lanceolate, ⅛ in. long, pale-green. Two outer glumes equal, lanceolate, acute, 1-nerved, smooth; 3rd or flowering glume ¼ shorter, thin and membranous, obtuse, minutely denticulate, 5-nerved; awn from the middle of the back, straight, about as long as the empty glumes, rarely wanting, callus set with short hairs. Palea wanting. Anthers large.

Var. mutica, Hack. MS.—Awn wanting.

South Island: Otago—Cromwell, Nevis Valley, Dunstan Mountains, Petrie! Lake Wakatipu, Kirk! 1000–2500 ft.

According to Professor Hackel this is nearest to A. canina, which differs in its bright-green smooth leaves, much more compound and closer panicle, smaller spikelets, in the scabrid keel of the empty glumes, and small anthera. A. Dyeri 28—Fl. page 866is separated by the innovation-shoots being intravaginal and not clothed with leafless scales, to say nothing of the broader leaves, dense panicle, and spikelets with the empty glumes scabrid on the keel.

6.A. parviflora, R. Br. Prodr. 170.—Culms laxly tufted, very slender, weak, often decumbent or prostrate at the base, erect or ascending above, quite smooth, 6–18 in. long. Leaves chiefly towards the base of the culms, the lowermost soon withering, 2–6 in. long, usually narrow and often almost filiform, but in luxuriant specimens broader and sometimes 1/12–1/10 in. diam., flaccid, flat or involute, smooth or the margins minutely scabrid; sheaths long, grooved, quite smooth; ligules long, membranous, lacerate. Panicle varying in length from 2 to 6 in. or more, compound, very lax and slender, drooping; primary branches long, capillary, scaberulous, erect at first but soon spreading, trichotomously divided, lowermost in clusters of 4–6, upper in distant pairs; secondary branches from above the middle, again divided; pedicels thickened at the tips. Spikelets very minute, about 1/15 in. long, shining, pale-green, sometimes tinged with purple. Two outer glumes slightly unequal, lanceolate, acute, membranous, slightly scabrid on the keel, margins hyaline; 3rd or flowering glume about ¼ shorter, broad, truncate, hyaline, delicately 5-nerved, awnless. Palea wanting.—Hook. f. Fl. Nov. Zel. i. 296; Handb. N.Z. Fl. 328. A. scabra, Benth. Fl. Austral. vii. 576 (not of Willd.).

North Island: Inland Patea and shores of Cook Strait, Colenso! South Island Pelorus Valley, J. Macmahon! near Westport, Townson! near Dunedin, Petrie!

I am greatly puzzled with this species, which can be recognised without much difficulty by the weak habit, very slender lax spreading panicle, and minute spikelets, which are smaller than those of any other New Zealand species. It was originally referred to A. parviflora by Hooker in the Flora, but does not quite match the plate of that species given in the "Flora Tasmanica" (t. 158), nor any Australian specimens that I have seen. Bentham referred the Australian plant to A. scabra, Willd., a North American species; but that is a larger and more erect plant, with a more copiously divided panicle, and with narrower spikelets, much more scabrid on the keel. Professor Hackel, who has examined my specimens, says, "Not easy to name. Surely not A. scabra, Willd., but very near the North American A. perennans, Tuck. It is most probably A. parviflora, R. Br., but without seeing one of Brown's types I cannot be quite sure of the identity." It should be mentioned that most of the specimens referred to A. parviflora by New Zealand botanists are nothing but small states of A. Dyeri, Petrie, (the A. canina of the Handbook), as, for instance, the plant figured as A. parviflora by Buchanan in his New Zealand Grasses, t. 20c. All such specimens can be at once distinguished by the strict habit, contracted panicle, and larger spikelets.

7.A. tenella, Petrie in Trans. N. Z. Inst. xxii. (1890) 442.—Apparently annual. Culms laxly tufted, erect, very slender, quite smooth and glabrous, 3–4-noded, 6–15 in. high. Leaves few, much shorter than the culms, erect, very narrow, filiform or setaceous, involute, finely striate; sheaths rather long, close, smooth; page 867ligules oblong, obtuse, lacerate. Panicle very long and narrow, 1½–4 in. by 1/10–⅙ in. broad, erect, pale-green; rhachis minutely scaberulous; branches few, fascicled, very short, erect; pedicels short, capillary, scaberulous. Spikelets 1/12–1/10 in. long, pale. Two outer glumes subequal, lanceolate, acute, shining, 1-nerved, slightly scabrid on the keel, smooth on the sides; 3rd or flowering glume about ¼ shorter, ovate-lanceolate, thin and hyaline, truncate, minutely denticulate, glabrous, faintly 5-nerved, awn wanting. Grain oblong.

South Island: Canterbury—Broken River, Petrie! Porter River, Kirk! Otago—Macrae's, Lake Wakatipu, Petrie! 1000–3000 ft.

A very distinct species, easily recognised by the very slender habit, excessively narrow pale-green panicle, and small shining spikelets.