Orchids of New Guinea

Pterostylis caulescens

Pterostylis caulescens L.O.Williams, Bot. Mus. Leafl. 12 (1946) 149, pl. 21

Type: Clemens s.n. (holo AMES # 61211)

Stem flexuose, with one or two leaves. Leaves long-petiolate; blade 5.5-7.5 by 1.4-1.8 cm, elliptic or elliptic-lanceolate, acute, membranous, tapering to the petiole; petiole 2-5 by 0.2-0.3 cm, channelled, half-clasping the stem at the base. Flower terminal, solitary. Median sepal about 3 by 1 cm, lanceolate, acuminate, about 9-nerved, puberulent dorsally. Lateral sepals about 3 by 0.4-0.5 cm, lanceolate, acuminate, puberulent dorsally, connate at the base for about one third of their length or less. Petals about 3 by 0.5 cm, elliptic or elliptic-lanceolate, acute, somewhat falcate, 7- to 9-nerved, puberulent dorsally. Lip about 1.3 by 0.4 cm, narrowly oblong-elliptic, with a conduplicate ridge down the centre, papillose, originating from the apex of the column-foot, with a recurved flattened appendage at the base which is about 0.4 cm long and penicillate at the apex. Column about 1.3 cm long; column-foot about 0.4 cm long. (After Williams, 1946)

Colours:

Flower flesh pink.

Habitat:

Epiphyte or terrestrial in mossy montane and subalpine forest; 2750 to 3450 m.

Distribution:

Malesia (New Guinea).

Distribution New Guinea:

Papua (Indonesia); Papua New Guinea. See map

Cultivation:

Cool growing humus epiphyte, requires shaded position.

Flowering time in the wild:

March, April, June, August, September, October.

References:

Royen, P. van, Alp. Fl. New Guinea 2 (1979) 96

Classification:

Family Orchidaceae
Subfamily Orchidoideae
Tribe Cranichideae
Subtribe Pterostylidinae
Genus Pterostylis
Species Pterostylis caulescens

Notes:

Differs from Pterostylis papuana mainly in the lack of a basal rosette of leaves. Also the inflorescence of P. caulescens tends to be much shorter. Pterostylis caulescens usually occurs as an epiphyte, while P. papuana is normally terrestrial.