Australian Tropical Rainforest Orchids

Thrixspermum platystachys

Starry Hairseed

Thrixspermum platystachys (F.M.Bailey) Schltr., Orchis 5: 55 (1911).

Sarcochilus platystachys F.M.Bailey, Syn. Queensl. fl., Suppl. 1: 56 (1886). Type: Johnstone River, Aug. 1892, J.L. Bancroft s.n. (holo BRI; iso K, MEL).

Thrixspermum neo-hibernicum Schltr. in K.Schum. & Laut., Fl. Schutzgeb. Sudsee, Nachtrage 232 (1905). Type: Neu-Mecklenburg: On trees in the village of Lauan, alt. c. 10 m, June 1902, R. Schlechter 14617 (holo B).


Occurs in north-eastern Queensland from Cape York to Townsville.

Altitude: 0-200 m.

Also occurs in New Guinea and the Solomon Islands.


Epiphytic or lithophytic herb forming coarse straggly pendulous clumps. Roots numerous, branching, 0.1-0.2 cm wide, wiry, tangled. Stems pendulous, 10-25 cm long, sparsely branched, flattened, supported by few roots. Leaves 5-10, scattered along stem, well-spaced, prostrate to pendulous, distichous, alternate, sessile, bases sheathing stem; lamina oblong to elliptic, 8-15 cm x 3-4 cm, green to yellowish green, stiff, leathery, apex unequally emarginate. Inflorescence an axillary raceme, 100-250 mm long, stiff, wiry, apex flattened, with distichous bracts; pedicels 15-25 mm long. Flowers numerous, 1-3 open at once, non-resupinate, erect to porrect, star-shaped, 30-40 mm x 40-60 mm, cream with orange and white labellum. Sepals and petals widely spreading, very narrow and tapering. Dorsal sepal erect, 30-35 mm x 3 mm. Lateral sepals slightly dilated near base, 30-35 mm x 3-4 mm. Petals obliquely erect, 25-30 mm x 1.5-2 mm. Labellum projected forward, 15 mm x 9 mm, 3-lobed; lateral lobes 3 mm x 6 mm, erect; midlobe thick, fleshy, tapered; spur 5 mm long, with a few short hairs. Column 5 mm long, narrowing toward base. Column foot very short. Capsules porrect, dehiscent.


Occurs in lowland rainforests and isolated trees near coast, where it typically grows in fairly exposed situations. It usually forms tangled clumps supported from the host by a few roots. The flowers are fragrant.

Widespread and sometimes common.

Flowering period: Sporadic throughout the year.

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