Poa colensoi Hook.f.
≡P. colensoi Hook.f. var. colensoi (autonym Cheeseman 1906 op. cit. p. 908);
Lectotype: K! Colenso 1589 [top Ruahine Mt] grass (designated by Edgar 1986 op. cit. p. 440).
=P. colensoi var. intermedia Cheeseman Man. N.Z. Fl. 908 (1906)
≡P. intermedia Buchanan Indig. Grasses N.Z. t. 48A (1880) non Koeler (1802);
Lectotype: WELT 59602 (Buchanan's folio)! without locality, collector or date (designated by Edgar 1986 op. cit. p. 440).
=P. guthrie-smithiana Petrie, T.N.Z.I. 45: 275 (1913)
≡P. colensoi var. guthrie-smithiana (Petrie) Zotov, T.R.S.N.Z. 73: 236 (1943);
Lectotype: WELT 66433a! D. P[etrie] ex H. G. S. [H. Guthrie-Smith] from Herekopere Island near Stewart Island grown in my [Petrie's] garden, Epsom, Auckland (designated by Edgar 1986 op. cit. p. 440).
=P. colensoi var. breviligulata Petrie, T.N.Z.I. 47: 57 (1915);
Lectotype: CHR 1468! D. Petrie Mt Egmont about 4000 ft, early Feb. 1912 (designated by Edgar 1986 op. cit. p. 440).
blue tussock
Small, blue-green or light green, narrow-leaved, stiff tussocks, 5-30-(70) cm, with tightly-packed shoots; branching intravaginal; leaf-blades disarticulating at ligule. Leaf-sheath light straw-coloured, later greyish brown, somewhat coriaceous, glabrous, indistinctly ribbed, tightly inrolled with narrow hyaline margins; upper sheaths sometimes purplish. Ligule 0.5-5.5 mm, entire, apically glabrous, rounded to tapered, abaxially minutely scabrid or smooth. Leaf-blade 5-15-(30) cm, usually tightly inrolled and c. 0.5 mm diam., abaxially glabrous, adaxially slightly to densely short pubescent-scabrid; margins finely scabrid, tip truncate, almost smooth with a few minute prickle-teeth, or fine-acicular and finely scabrid. Culm 5-20-(40) cm, erect, usually overtopping but often = leaves, internodes glabrous. Panicle 1-10-(15) cm; branches ± spreading, few to many, often short, almost filiform, smooth to ± finely scabrid, tipped by 1-3 rather large spikelets. Spikelets (3.5)-5-7-(10.5) mm, 2-5-(7)-flowered, light green to brownish. Glumes subequal, subacute to acute, glabrous, midnerve with a few minute prickle-teeth near tip; lower 2-3-(4) mm, 1-3-nerved, narrow elliptic-lanceolate, upper (2)-2.5-3.5-(4) mm, 3-nerved, ovate- to elliptic-lanceolate; margins minutely fimbriate. Lemma (2.5)-3-4-(5) mm, 5-nerved, ovate- to elliptic-lanceolate, subobtuse, in some long-liguled plants with fine hairs on lower ½-⅓ of midnerve and short hairs near base of lateral nerves, otherwise nerves scabrid or smooth, internerves densely scabrid to smooth, rarely with a few scattered hairs near base; margins glabrous to finely ciliate-scabrid. Palea 2-4-(5) mm, keels finely ciliate-scabrid, interkeel minutely pubescent-scabrid. Callus in long-liguled forms sometimes with a tuft of tangled hairs, otherwise glabrous or very rarely with a few short wispy hairs. Rachilla 0.5-1 mm, smooth to strongly densely scabrid. Lodicules c. 0.5 mm. Anthers 1-2 mm. Caryopsis c. 1-2 × 0.5 mm. 2 n = 28. Plate 7E.
Endemic.
A long-liguled (> 2 mm) form is dominant in North Id and also in northern South Id in Nelson, Marlborough and in Canterbury about as far south as Banks Peninsula; on Mt Egmont, North Id and in South Id southwards from Banks Peninsula plants are predominantly short-liguled (0.5-1.5 mm). In plants with long ligules the leaf tips are blunt and the lemma nerves may be silky haired towards the base. In some long-liguled plants from South Id, however, the lemmas are completely glabrous or occasionally scabrid. In contrast, short-liguled plants have acicular leaf-tips and vary in scabridity of the lemma; lemmas may be densely minutely prickle-toothed, occasionally with scattered hairs near the base, especially on the nerves; or lemmas may be completely glabrous, or minutely prickle-toothed only on the nerves.
On Mt Egmont, North Id, and in western Otago, Southland, and Stewart Id, some plants may have lemmas with almost glabrous internerves and a few short hairs near the base of the nerves and between the outer lateral nerves and margins, thus resembling P. hesperia in features of the lemma. However, the stiff, short, blue-green, tussock-habit and shorter spikelets distinguish these western and southern plants of P. colensoi from the lax, rhizomatous, light green, turf-forming P. hesperia.
Very fine-leaved plants are also found, e.g., CHR 387358 A,B, A. P. Druce, Pelorus Valley, Marlborough, Dec. 1981, a long-liguled plant; in marked contrast are the stiff, very pungent-leaved plants on the Remarkables, e.g., OTA 34687 C. D. Meurk 2.5.1971.
