.jpg)
Manual of the New Zealand Flora.
26. Triodia, R. Br
26. Triodia, R. Br.
Perennial grasses, of very various habit. Leaves narrow, rigid. Spikelets 2-to many-flowered, arranged in a lax or narrow panicle; rhachilla disarticulating above the 2 outer glumes and between the flowering glumes. Two outer glumes longer or shorter than the flowering glumes, somewhat rigid, empty, keeled, acute, awnless. Flowering glumes more or less imbricated, rounded on the back at the base, coriaceous or chartaceous, often hairy on the margins and callus, 3-nerved, 3-lobed or 3-toothed at the apex, the lobes equal or the central one produced into a short awn or mucro. Palea broad, thin, with 2 almost marginal keels. Lodicules 2. Stamens 3. Styles short, distinct; stigmas plumose. Grain usually compressed on the back, free within the flowering glume and palea.
Species from 25 to 30, mostly in the temperate regions of both hemispheres, a few in tropical America. The New Zealand species belong to the subgenus Rhombolytrum, characterized by the lateral teeth of the flowering glume being very small or almost obsolete, the middle tooth being also small and mucronate. It contains a few Chilian and North American species in addition to the three found in New Zealand, all of which are endemic.
Densely matted; culms 1–3 in. Panicle often reduced to a single spikelet. Outer glumes ovate. Flowering glumes silky on the margins, distinctly 3-toothed at the apex 1.T. exigua. Culms tufted, 2–6 in. Panicle of 8–12 spikelets. Outer glumes lanceolate. Flowering glumes sparsely silky, 5–7-nerved, minutely 3-toothed at the apex 2. T. pumila. Culms tufted, 2–4 in. Panicle of 6–15 spikelets. Outer glumes broadly ovate. Flowering glumes glabrous, 9-nerved, obscurely 3-toothed or irregularly erose at the apex 3.T. australis.
| 1. | T. exigua,T. Kirk in Trans. N.Z. Inst. xiv. (1882) 378.—Small, densely matted, forming a compact sward. Rhizomes long, creeping, branched. Culms erect from the rhizome, slender, wiry, glabrous, 1½–4 in. high. Lower leaves reduced to sheathing scales; upper shorter than the culms, ½–2 in. long, very narrow, convolute, filiform, rigid, erect or curved, acute or almost pungent at the tip, quite glabrous; sheaths closely appressed, pale, membranous, grooved; ligules reduced to a line of short stiff hairs. Panicle frequently reduced to a single spikelet, sometimes 2–3, rarely as many as 4–5; pedicels short, slender, minutely scaberulous. Spikelets about ⅕ in. long, ovoid-oblong, 2–4-flowered. Two outer glumes subequal, as long as the flowering glumes or very slightly shorter than them, concave, ovate, subacute, rigid, the lower one 5-nerved, the upper 7-nerved. Flowering glumes broadly ovate, silky on the margins and back towards the base, minutely scaberulous above, 9-nerved, shortly 3-toothed at the apex, the middle tooth mucroni-form, not much longer than the lateral teeth. Palea broad, ciliate on the keels.—Danthonia pauciflora, Buch. N.Z. Grasses, t. 36B (not of R. Br.).
page 896
South Island: Nelson—Clarence Valley, T. F. C.Canterbury—Upper Waimakariri and Broken River, Enys! Kirk! Cockayne! T. F. C.Otago—Not uncommon in the dry plains of the central and north-western portions of the district, Petrie! 500–3000 ft. A curious little species, with much of the habit of small states of Zoysia pungens. |
| 2. | T. pumila,Hack. MSS.—Culms tufted, slender, glabrous, much branched at the base, 2–8 in. high. Leaves shorter than the culms, very narrow, involute, filiform, strict, erect, 1–2 in. long; sheaths pale, membranous, deeply grooved, glabrous or sparingly pilose with long soft hairs; ligules reduced to a transverse ring of hairs. Panicle ½–1 in. long, strict, erect, much contracted, of 3–15 spikelets; branches very short, erect, pubescent. Spikelets ⅙–⅕ in. long, lanceolate, 2 - 3 - flowered. Two outer glumes exceeding the flowering glumes, subequal, lanceolate, acute or subacute, 3–5-nerved. Flowering glumes broadly ovate, sparsely silky-pilose on the margins and back, faintly 5–7-nerved, minutely 3-toothed at the apex, the central tooth mucroniform. Palea bifid at the tip, 2-keeled, ciliolate on the keels.—Atropis pumila, Kirk in Trans. N.Z. Inst. xiv. (1882) 379.
South Island: Canterbury—Upper Waimakariri and Broken River, Kirk! T. F. C.;mountain s near Lake Tekapo, T. F. C.Otago—Not uncommon in mountainous districts, Buchanan! Petrie! Kirk! Aston!Altitudinal range usually from 2000 to 5000 ft., but descending to sea-level in the south of Otago. Referred to Atropis by Mr. Kirk, but clearly a Triodia, and closely allied to the following species, from which it differs in the longer and narrower spikelets, narrow outer glumes, and silky flowering glumes, which are distinctly though minutely 3-toothed at the apex. |
| 3. | T. australis, Petrie in Trans. N.Z. Inst. xxii. (1890) 442.—Culms densely tufted, much branched at the base, erect or spreading, quite glabrous, leafy below, 2–4 in. high. Leaves usually shorter than the culms, narrow, involute, filiform, deeply striate; sheaths broad, grooved, pale; ligules reduced to a narrow band of short white hairs with a longer tuft on each side. Panicle small, strict, erect, contracted, ½–¾ in. long, of 6–15 spikelets; branches 4–6, short, pubescent. Spikelets about ⅛ in. long, 2–4-flowered. Two outer glumes rather shorter than the flowering glumes, subequal, broadly ovate, obtuse, 7-nerved; margins broad, pale. Flowering glumes very broadly ovate or rounded, glabrous, firm, 9-nerved, minutely and irregularly 3-toothed or erose at the tip, Palea broad, 2-keeled, the keels ciliolate.
page 897
Var. mucronulata, Hack. MSS.—Sheaths pilose with long hairs. Spikelets 3–5-flowered, the outer glumes distinctly shorter than the flowering glumes, which are more evidently 3-toothed, the middle tooth produced into a short mucro. South Island: Otago—Sides of mountain-streams. Clark's Diggings, Mount Cardrona, Old Man Range, Maungatua, Blue Mountains, Peine! Var. mucronulata; Swamps in the Tasman Valley, Canterbury, T. F. C. 2000–5000 ft. |