Peristylus affinis (D.Don) Seidenf., Dansk Bot. Ark. 31, 3 (1977) 48, fig. 23
Basionym: Habenaria affinis
Tuber cylindrical, when dried 2.5-4 cm long. Stem erect, c. 25 cm long, cataphylls c. 6, tubular, the upper ones with a small leaf-blade. Leaves c. 6, crowded at the stem apex, lanceolate, 10-11 by 2.5-3.8 cm, acute or subobtuse, conical-apiculate, narrowed at the base, c. 5-nerved, mid-rib prominent below; sheath tubular. Inflorescence straight, many-flowered; peduncle 18.5 cm long, with several linear-lanceolate peduncle-scales similar to the bracts; rachis 20 cm long. Floral bracts linear-lanceolate, gradually acuminate, to 1.3 cm long. Flowers very small, erect. Median sepal ovate, 0.4 by 0.23 cm, obtuse, concave, 1-nerved. Lateral sepals obliquely oblong, obtuse, apiculate, at the base adnate to the lip, concave, 1-nerved, in total 0.43 cm long, free part 0.38 by 0.18 cm. Petals cohering with the median sepal, strongly oblique, 0.43-0.46 by 0.25 cm, broadly obtuse, narrowed towards the base, along the basal margin for 0.15 cm adnate to the lip and the column, in the middle dilated into a broad rounded lobule, 1-nerved. Lip at the base adnate to the column, spurred, 3-lobed, 3-nerved, when flattened 0.54-0.58 cm long, between the tips of the lateral lobes 0.45 cm wide, basal part concave; lateral lobes obliquely semiovate, gradually acuminate, obtuse, as long as the median sepal, at the base 0.08 cm wide; mid-lobe broadly triangular, obtuse, 0.15 by 0.18 cm; spur subglobose-scrotiform, at the base strongly constricted, rounded, 0.13 cm long. Column very short. Stigmata adnate to the lip. Ovary erect, at the apex recurved, twisted, 6-grooved, 0.6 cm long. (After Smith, 1911)
Colours: Flower light yellow.
Habitat: on cliffs, grassy banks and in Imperata grassland; 450 to 1900 m.
Flowering time in the wild: January, February, April, May, October, November, December.
Distribution: Malesia (New Guinea), Thailand, ?Laos, NW Himalaya to India (Naga Hills), China.
Distribution in New Guinea: Papua (Indonesia); Papua New Guinea. See map: 542-1M.JPG.
Cultivation: Warm to cool growing terrestrial, requires shaded position.
Note: Very similar to Peristylus goodyeroides (D.Don) Lindl., and often recorded under this name from New Guinea. The delimitation between these two species requires further study.