Hydnophytum archboldianum Merr. & L.M.Perry

36. Hydnophytum archboldianum Merr. & L.M.Perry View in CoL — Fig. 39 View Fig

Hydnophytum archboldianum Merr. & L.M. Perry (1945) 16. — Type: Brass 9506 (lectotype selected here A; iso L), New Guinea, Papua Province, Lake Habbema ,Aug. 1938 .

Terrestrial to epiphytic. Tuber large, surface rugose, brownish yellow. Entrance holes rimmed to 1 cm across. Tuber tissue purple. Stems several, branching and spreading, to 30 by 0.6 cm. Internodes 0.5–6 cm. Lamina elliptic-lanceolate; 2.3 by 1 to 5 by 3.3 cm; apex round apiculate to acute; base rounded; leathery; midrib prominent above and below, veins 4–6, more prominent above, slightly impressed below. Petiole to 0.2 cm; stipules to 0.2 cm, triangular, more or less persistent, falling before leaves. Inflorescence paired, sessile; bracts 0.5–0.8 cm, papery, with numerous reddish hairs within. Flowers [2] heterostylous. Calyx to 1.5 mm, 4-cuspidate. Corolla tube 7–8 mm, lobes 3 mm, pale purple to purple-red, with a broad band of short hairs from lobes to well within corolla tube. Short-styled flowers with anthers 1.8 mm, exserted on 1 mm filaments, stigma 2-fid at mouth of tube. Long-styled flowers with anthers 1.8 mm, within mouth of tube, stigma 2-fid, exserted above anthers. Pollen 3-colpate, 74 (68–78) μm, brochi 2–3 μm. Fruit obovate, 8 mm, red. Pyrenes 2 or 3, obovoid, 3 by 2 mm; apex rounded; base tapering.

Ecology & Habitat — Terrestrial or epiphytic in alpine scrub, above 3 000 m. Tuber not inhabited by ants.

Distribution — Indonesia (Papua Province).

Conservation status — Vulnerable (VU) under criteria D2 with only the type location known, a previously remote area, that is now accessible by 4WD with the concomitant risk of ecological degradation.

Additional specimens examined. Brass 9240 (A, BO, BRI, L), Brass 9492 (A, BO, BRI, L), S4°07' E138°40', Lake Habbema, 3 225 m camp.

Notes — The tuber tissue is purplish red, and the flowers are said to be purple in colour, although this probably applies to the lobes only. These characters are shared by two species of Hydnophytum from Papua New Guinea: H. magnirubrum [37] and H. minirubrum [38]. Hydnophytum archboldianum has more leathery, oblong leaves and flowers with less fleshy lobes.

According to Merrill & Perry (1945), Brass suspected that certain plants lacked a tuber, all his numbers are annotated as shrubs, and for Brass 9240 and 9492 no tuber is mentioned. It seems improbable that this species sometimes lacks a tuber, and it is more likely that after an extended period of growth, the stems may appear at some distance from the original tuber, which becomes buried in leaf litter or moss.