Dendrobium rigidum – Smooth tongue orchid

Published: Journal December 2021

Pronounced: den-DROH-bee-um RIJ-ih-dum
Family: Orchidaceae
Derivation: Dendron from Greek meaning tree and bios meaning life, meaning one who lives on trees; rigidum from Latin meaning stiff, hard or inflexible.

Dendrobium rigidum is an epiphytic or lithophytic herb with wiry, hanging stems 20–30mm long and about 3mm wide. The leaves are egg-shaped, smooth and fleshy, dark green, 30–60mm long and about 15mm wide. The flowering stem emerges from near a leaf base and is 10–30mm long. There are between two and seven cream-coloured flowers 9–12mm long, 12–15mm wide with the sepals and petals spreading apart with their bases overlapping. The sepals are 7–9mm long, about 4.5mm wide and the petals are a similar length but less than half as wide. The labellum is curved, about 10mm long and 7mm wide with red or orange markings. Flowering occurs sporadically throughout the year.

The smooth tongue orchid grows on trees, shrubs and sometimes on rocks in mangroves, paperbark swamps and rainforest in New Guinea, on some Torres Strait Islands and on the Cape York Peninsula as far south as the
Russell River.

(Source ‘Atlas of Living Australia’ website ala.org.au)