Flora of New Zealand Series

Type locality: "Open scrub and low bush on the banks of Kelly's Creek, Otira River (1,000 ft.), in flower in early part of January". Lectotype: WELT 3651, D. Petrie, Jan. 1893.

Plant 10–25–(35) cm. tall. Stem c. 2 mm. diam., smooth, sts ± decumbent; internodes mostly rather shorter than lvs, sts very short near base. Lf-shape changing gradually from below upwards; lamina of lower lvs c. 5–10 × 2–3 cm., oval to broad-elliptic or narrow-obovate, obtuse, narrowing to broadly winged, us. short petiole; upper lvs progressively more acute, the uppermost little shorter but sessile, ovate, sts almost acuminate, often reaching but rarely overtopping fl. Fl. solitary; ovary us. erect. Dorsal sepal c. 3–4–(5) cm. tall, very slightly to much inclined in its proximal part, tip long, narrow, ± parallel-sided with only weakly involute margins, the whole often strongly curved downwards; lateral sepals diverging at a narrow angle, caudae of lobes very long, erect to strongly bent backwards or forwards. Petals much shorter than dorsal sepal, acute. Labellum narrow-triangular, arched and protruding, apex narrowly obtuse. Column shorter than labellum; stigma long-oval, rather flat.

DIST.: S. Mt Arthur-Cobb area; Arthur's Pass-Otira area.

Endemic.

Open places, us. near forest.

FL. 12–1.

The original gathering is also represented by WELT 3631, 3632 and 3634 in Herb. Petrie, one of the plants having 2 fls, as happens occ. in most solitary-fld spp.

P. oliveri is common and well known in the Arthur's Pass area and has been collected occ. over the last 60 years in the Mt Arthur-Cobb high country in Nelson, but no records are known from intermediate places.

A striking feature of the fl. in the wild is the tendency for the dorsal sepal to curve strongly downwards, its tip sts reaching to the ovary, while the caudae of the lateral sepals may curl far backwards. In cultivation this curvature may be much reduced; e.g. a plant originally bearing typically curved sepals flowered in two successive seasons in the glasshouse and in each fl. the tip of the dorsal sepal remained permanently horizontal.

Petrie dedicated his sp. to "Professor D. Oliver, F.R.S., of Kew, in acknowledgement of valued assistance in my botanical studies".