Flora of New Zealand Series

U. riparia R.Br. var. affinis Col. ex C. B. Clarke in J. Linn. Soc. (Bot.) 20, 1883, 392.

U. purpurata Petrie var. subcaespitosa Kük. in Pflanzenr. 38, 1909, 61.

Type: K, Dry hills (Ruahine Mountains?), Colenso 1643.

Densely caespitose. Culms (10)–25–50–(80) cm. tall, 0.5–1 mm. diam., sharply trigonous, scabrid below infl., often drooping; basal sheaths dull dark brown. Lvs 3–4 per culm, = or slightly < culms, 1.5–2 mm. wide, yellow-green, margins harshly scabrid, slightly involute when dry. Spikes 5–11–(14) cm. long, female fls c. 15–20, lax, internodes 11 mm. long at base of spike, 3–6 mm. long above. Glumes ± = or rarely much < utricles, persistent, obtuse or lowermost subacute, coriac., pale brown. Utricles 6–7 × c. 1 mm., plano-convex, lanceolate or oblong-lanceolate, grey-brown, nerved, slightly contracted or cuneate at the base forming a stipe 1.5–2 mm. long, beak 2 mm. long.

DIST.: N. Mt Egmont, Ruahine and Tararua Ranges. S. Scattered in mountains throughout.

Forests, 600–1,200 m. altitude in North Id, descending to near sea level in South Id.

U. purpurata var. subcaespitosa was based on specimens from "Südinsel, Mt Cook in Westland (Cheeseman!); Old Man Range in Otago (Petrie apud Cockayne n. 78211)". Hamlin (1959, p. 30) chose as lectotype WELT 1701, Old Man Range, 3,000 ft, Petrie, no. 7821 in Herb. Cockayne, Nov., 1893; isotype at CANTY.

Hamlin (1959, p. 31) notes that the tussocks of U. affinis may reach 1 m. or more across the base.

Both U. affinis and U. laxiflora were treated by Cheeseman (Man. N.Z. Fl. 1925, 248) and by Kükenthal (Pflanzenr. 38, 1909, 63) as var. affinis of the Australian sp. U. riparia R. Br. Although U. riparia resembles these 2 N.Z. spp. in having persistent glumes and many-nerved, long, narrow utricles, its lvs are not so harshly scabrid, its utricles are more membr., and its spikes are shorter and not so lax-fld.