Flora of New Zealand Series

; Holotype: CHR 389678! A. P. Druce Dun Mt, Nelson, 3500 ft, tussock land (on mineral belt), Jan. 1980.

Small tufts with erect leaves; tufts sometimes aggregated or rhizomes interconnecting to form loose mats.

S.: eastern Nelson and western Marlborough. Subalpine on ultramafic soil.

Endemic.

Poa acicularifolia subsp. ophitalis in ultramafic sites at Dun Mt and Wooded Peak in Nelson, and on Red Hills in western Marlborough, may be mistaken for P. colensoi, but can be distinguished by the adaxially smooth, not scabrid, leaf-blades and the short-hairy lemmas; the lemma of P. colensoi from eastern Nelson and the Mineral Belt is almost glabrous or shortly scabrid.