Very close to the following species, of which it may prove to be a variety, and from it is mainly separated by the glabrous rhachilla and rather larger spikelets.
5. D. tenella, Petrie in Trans. N.Z. Inst. xxiii. (1891) 402.—Culms tufted, branched at the base, extremely slender, flaccid, quite smooth, leafy throughout, 6–14 in. high. Leaves bright-green, very narrow, capillary, involute, flaccid, the uppermost often exceeding the young panicle; sheaths smooth, grooved; ligules long, acute, membranous, broader than the blade and decurrent along the margins of the sheaths. Panicle very slender, 2–6 in. long, contracted at first, but becoming lax and somewhat effuse; branches in pairs, few, rather distant, capillary, scabrid, trichotomously divided. Spikelets few towards the tips of the branches, small, 110 in long, pale, glistening, 2-flowered. Two outer glumes unequal, much shorter than the spikelet, membranous, 1-nerved or the upper 3-nerved; 3rd and 4th or flowering glumes broadly oblong, delicately hyaline, faintly 5-nerved, silky at the base, truncate at the apex and 3-toothed, the middle tooth often bifid, the 4th always with a minute dorsal awn inserted just below the apex, the 3rd frequently awnless. Palea bifid, 2-nerved, the nerve finely ciliate. Rhachilla elongated between the flowering glumes and more or less silky, produced above the upper flower into a silky bristle.—D. Hookeri, T. Kirk in Journ. Bot. xxiv. (1891) 237 (in part). Catabrosa antarctica, Hook. f. Fl. Nov. Zel. i. 308 (but not of Fl. Antarct. i. 102); Buck. N.Z. Grasses, t. 41b.
North Island: Ruahine Mountains, Colenso! Tararua Mountains, H. H. Travers! South Island: Nelson—Mount Arthur, A. McKay! Otago—Near Dunedin, Catlin's River, Clinton Saddle, Petrie! Sea-level to 4500 ft.
This differs from both D. novæ-zealandiæ and D. Chapmani in the silky rhachilla, and from the former in addition in the dorsal awn being present in at least the upper flower. It varies greatly in the size of the spikelets and in the proportionate length of the outer glumes. Mr. Petrie's original specimens from Catlin's River have the spikelets barely more than 112 in. long, and the upper outer glume is not half the length of the spikelet; but those from the Clinton Valley, and Mr. Colenso's from the Ruahine Range, have much larger spikelets with longer outer glumes.
6. D. gracillima, T. Kirk in Journ. Bot. xxiv. (1891) 237.—Culms tufted, usually with intravaginal branches near the base, erect, slender, glabrous, 2–8 in. high. Leaves towards the base of the culms and much shorter than them, strict, erect, very narrow, setaceous or filiform, convolute; sheaths rather lax, grooved; ligules long, membranous, usually split at the tip. Panicle erect, ovate or deltoid, open, ¾–2 in. long; branches few, binate, capillary, smooth or almost so. Spikelets ⅛–⅙ in. long, on pedicels longer than themselves, 2-flowered. Two outer glumes unequal, 3-nerved, shorter than the spikelet; 3rd and 4th or flowering glumes densely
