Manual of the New Zealand Flora.
18. Deyeuxia, Clarion
18. Deyeuxia, Clarion.
Annual or perennial grasses. Leaves flat or involute; ligules membranous. Spikelets small, 1-flowered, arranged in effuse or contracted or spike-like panicles with capillary whorled branches; rhachilla disarticulating above the 2 outer glumes, produced beyond the flower into a silky bristle. Glumes 3; 2 outer equal or sub-equal, persistent, empty, keeled, acute, not awned, usually 1-nerved; 3rd or flowering glume shorter than the empty glumes or equalling them, thin and hyaline or rigidly membranous or almost coriaceous, 5-nerved, entire or 2–4-dentate, callus at the base silky; awn generally present, straight or twisted, inserted above or below the middle of the glume. Palea more than half as long as the flowering glume or almost equalling it, thin, 2-nerved or 2-keeled. Stamens 3. Styles distinct, short; stigmas plumose. Grain oblong or obovoid, enclosed w thin the flowering glume and palea.
Species over 100, widely dispersed through the temperate regions of both hemispheres, particularly abundant in Andine South America. It is not at all easy to separate Deyeuxia from the allied genera Agrostis and Calamagrostis, and of late many authors, including Hackel, have placed the majority of species under the latter genus. It appears to me, however, that there is much to be said in favour of the arrangement, proposed in Hooker's "Flora of British India" (Vol. vii., p. 253), where Agrostis is limited to species in which the rhachilla is not produced at the back of the flower, and in which the callus of the flowering glume is naked or nearly so, Calamagrostis containing those in which there is also no prolongation of the rhachilla, but which have the callus villous with long hairs, while in Deyeuxia the species have both an elongated rhachilla and hairy callus. Understood in this sense, there are 7 New Zealand species of the genus, 3 of which extend to Australia and Tasmania, the remaining 4 being endemic.
Slender, 4–12 in. Leaves filiform. Panicle 1–2½ in. Spikelets ⅛ in. long; callus-hairs very long | 3. D. setifolia. |
Slender, 9–36 in. Leaves narrow, involute. Panicle 2–5 in. Spikelets ⅙–¼ in.; awn from below the middle, exserted; callus-hairs short. Rhachilla obviously produced | 4. D. avenoides. |
Tall, slender, 2–4 ft. Leaves flat, ⅙–¼ in. broad. Panicle 4–6 in. Spikelets ⅙–¼ in.; awn short, almost terminal. Rhachilla obviously produced | 5. D. Youngii. |
Tall, stout or slender, 1–3 ft. Leaves flat or involute. Panicle 2–6 in. Spikelets ⅛ in.; flowering glume 4-cuspidate; awn from near the base. Rhachilla not produced or very obscurely so | 6. D. quadriseta. |
Slender, 1–3 ft. Leaves flat, flaccid. Panicle 3–6 in., lax but narrow. Spikelets ¼–⅓ in.; callus-hairs long; awn from about the middle. Rhachilla obviously produced | 7. D. Petriei. |
1. | D. Forsteri, Kunth, Rev. Gram. i. 77.—Annual or rarely perennial, very variable in size and habit. Culms tufted, erect or decumbent at the base, slender, smooth, 2–4-noded, 6–24 in. high. Leaves shorter than the culms, very narrow and involute or broader and flat, 1/12–⅙ in. diam., almost glabrous or scaberulous on the margins and principal veins; sheaths smooth, grooved, the uppermost usually long; ligules long, narrow, membranous. Panicle 3–12 in. long, usually very lax and spreading when mature, but contracted in the young state; branches in distant whorls or clusters, the lowermost 2–6 in. long or more, repeatedly trichotomously divided, finely capillary, scabrid; pedicels very slender. Spikelets numerous, pale-green, 1/12–⅛ in. long. Two outer glumes subequal, lanceolate, acuminate, membranous, 1-nerved, keel scabrid; 3rd or flowering glume ⅓–½ shorter, oblong, truncate, minutely 4-denticulate, hyaline, more or less silky on the sides and with a tuft of hairs at the base; awn from the middle of the back, slender, straight or bent. Palea narrow-linear, bifid at the apex. Rhachilla usually produced behind the palea as a short silky bristle, but often very small and hardly perceptible.— Hook. f. Fl. Nov. Zel. i. 298; Benth. Fl. Austral. vii. 579. Avena filiformis, Forst. Prodr. n. 46. Agrostis avenacea, Gmel. Syst. i. 171. A. Forsteri, Roem. and Schult. Syst. ii. 359; A. Rich. Fl. Nouv. Zel. 131; A. Cunn. Precur. n. 253; Raoul, Choix, 39. A. æmula, R. Br. Prodr. 172; Hook. f. Handb. N.Z. Fl. 329; Buch. N.Z. Grasses, t. 21. A. Solandri, F. Muell. Veg. Chath. Isl. 60. North and South Islands, Stewart Island, Chatham Islands: Abundant throughout. Sea-level to 3000 ft. Var. pilosa, Cheesem.—Coarser and more robust. Leaves broader, ¼–⅓ in. or even more, flat. Spikelets slightly larger.—D. pilosa, Buch. Man. |
N.Z. Grasses, 6. Agrostis pilosa, A. Rich, Fl. Nouv. Zel. 134, t. 23 Raoul, Choix, 39; Hook. f. Fl. Nov. Zel. i. 297 Handb. N.Z. Fl. 329; Buck. N.Z. Grasses, t. 22.
North and South Islands Damp subalpine localities, not uncommon. Hardly more than a luxuriant state of the type.
Var. semiglabra, Hack. MS.—Flowering glume glabrous on the back, its callus sparingly pilose. Otherwise as in the type.
North and South Islands Not uncommon.
Var. humilior, Hack. MS.—Root often perennial. Culms 3–10 in. high. Panicle very broad and spreading; branches few, distant, binate, few-flowered. —A. striata, Col. in Trans. N.Z. Inst. xxi. (1889) 107.
North and South Islands: Probably not uncommon in mountain districts, Lake Waikaremoana, Hill! Clarence Valley, Lake Tennyson, Broken River. Tasman Valley, &c, T. F. C.;Lake Te Anau, Petrie!
Var. littoralis, Hack. MS.—Root annual. Culms 2–9 in., often forming a compact sward. Panicle rather narrow, contracted, many-flowered. Empty glumes linear-lanceolate, narrower than in the type.
Kermadec Islands, North and South Islands Rocky or gravelly places near the sea, not uncommon.
Var. Lyallii, Hack. MS.—Culms 6–12 in. Leaves narrow, involute. Panicle lax branches few, binate or ternate. Spikelets larger, ⅛–⅙ in. long. Flowering glume densely clothed with silky hairs.—A. Lyallii, Hook. f. Fl. Nov. Zel. i. 297.
South Island:Near Westport, Townson!Okarito, A.Hamilton! Jackson's Bay, Kirk! Milford Sound, Lyall, Kirk! Catlin's River, Petrie! Auckland Islands: Kirk!
Var. micrathera, Hack. MS.—Habit of var. Lyallii, but larger and leaves broader. Spikelets still larger, ⅕–¼ in. long. Empty glumes linear-lanceolate, acuminate. Flowering glume short, ½as long as the empty glumes, very thin, sparingly silky; awn from above the middle, short, delicate, hardly exserted beyond the empty glumes.
Antipodes Island, Campbell Island Kirk! Possibly the same as Agrostis leptostachya,Hook. f. Fl. Antarct. i. 94, but I have not seen an authenticated specimen, and it is described as having no palea and a long awn.
D. Forsteri is one of the most generally diffused plants in New Zealand, and is certainly one of the most variable. In attempting to characterize its chief forms, I have mainly followed the grouping suggested to me by Professor Hackel, who has kindly examined sets of all the varieties contained in my herbarium. The species is as plentiful in Australia and Tasmania as in New Zealand.