Australian Tropical Rainforest Orchids

Thrixspermum congestum

Cupped Hairseed

Thrixspermum congestum (F.M.Bailey) Dockrill, Austral. Sarcanth. 27, t. 35 (1967).

Cleisostoma congestum F.M.Bailey, Proc. Roy. Soc. Queensland 11: 17 (1895). Type: Queensland, Cairns, Aug.1894, L.J. Nugent 10 (holo BRI).


Occurs in the Northern Territory on Melville Island, and in north-eastern Queensland from Iron Range to the Tully River.

Altitude: 0-200 m.

Also occurs in Indonesia, New Guinea and the Solomon Islands.


Epiphytic or lithophytic herb forming small clumps. Plants usually consisting of a single projecting growth with numerous thin roots. Stems erect to porrect, 5-15 cm long, sparsely branched, flattened. Leaves 6-15, scattered along stem, crowded, erect to prostrate, distichous, alternate, sessile, bases sheathing stem; lamina oblong, 4-6 cm x 0.7-0.9 cm wide, green, often yellowish green, stiff, leathery, apex unequally emarginate. Inflorescence an axillary raceme, erect, 50-100 mm long, wiry, apex expanded, with whorl of congested bracts; pedicels 5-7 mm long, including ovary. Flowers numerous, 1-4 open at once, non-resupinate, erect, star-shaped, 9-11 mm x 12-15 mm, cream or white, fragrant. Sepals and petals cupped but widely spreading. Dorsal sepal erect, ovate, 6-7 mm x 3 mm, apex acute. Lateral sepals free, widely divergent, ovate, falcate, 6-7 mm x 4 mm, apex acuminate. Petals obliquely erect, linear to lanceolate, 6 mm x 2 mm. Labellum projected forwards, 5 mm x 2 mm, 3-lobed; lateral lobes erect, 1.5 mm x 3 mm, hairy; midlobe short, fleshy, hairy; spur short, hairy. Column 2.5 mm long. Column foot 1 mm long, almost at right-angles to column. Capsules porrect, dehiscent.


Occurs in lowland rainforests and on mangroves, usually in humid airy situations. It is often found perched in exposed positions on small branches. The flowers are fragrant.

Widespread and common.

Flowering period: Sporadic throughout the year.

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