Tetrabaculum tetragonum—Tree Spider Orchid—ORCHIDACEAE.

Tetrabaculum tetragonum

Link to Images on Flickr.

Habitat—Usually growing in heavily shaded areas on large rainforest trees - sometimes quite high up (10-15 m). Grows along streams in coastal districts.

Distribution— North from Illawarra in New South Wales onto Queensland..

Description—Epiphyte, occasionally a lithophyte orchid with long, pendulous, four-sided canes (pseudobuibs) with wiry bases. The pseudobulbs grow to 45 cm by 9 mm diam. They are swollen, succulent, and distinctively square in the cross section in the upper half, then tapering towards the tip. Plants root only at the base. Roots are smooth and creeping.

Local occurrences

Cape Hawke and Zamia Place Reserve.

Leaves.— Up to 5, 8cm long by 25 mm wide, leathery.

Tetrabaculum tetragonum
Tetrabaculum tetragonum

Inflorescence.—Flowering stem to 4 cm long with up to 5 flowers. Flowers 2.5 cm across with thin segments, yellowish or greenish with red margins, sometimes with reddish purple splotching. Very showy when in flower.

Flowering.—September to October.