Plectorrhiza tridentata, commonly known as the common tangle orchid,[1] is an epiphytic or lithophytic orchid that has many coarse, tangled roots, up to twenty egg-shaped leaves and up to fifteen green or brown, star-shaped flowers with a white labellum. It grows on rainforest trees and in other humid places and occurs between the Daintree National Park in Queensland and the far north-eastern corner of Victoria.
Plectorrhiza tridentata is an epiphytic or lithophytic herb with a single main flattened stem, NaNmm long suspended by one to a few of its many tangled aerial roots. There are between three and twenty green to purplish, leathery, narrow egg-shaped leaves NaNmm long and NaNmm wide. Between three and fifteen green or brown flowers, NaNmm long and NaNmm wide are borne on a pendulous flowering stem NaNmm long. The sepals and petals are free from each other and spread widely apart. The dorsal sepal is NaNmm long, about 2mm wide and the lateral sepals are slightly longer. The petals are NaNmm long, about 1.5mm wide. The labellum is white with a green patch, NaNmm long, about 4mm wide with three lobes. The side lobes are more or less triangular and curve outwards and the middle lobe is blunt with a curved spur about 2mm long. Flowering occurs from September to January.[2] [3] [4] [5]
The common tangle orchid was first formally described in 1838 by John Lindley who gave it the name Cleisostoma tridentatum and published the description in Edwards's Botanical Register.[6] [7] In 1967 Alick Dockrill changed the name to Plectorrhiza tridentata.[8] The specific epithet (tridentata) is derived from the Latin word tridens meaning "a fork with three tines".[9]
Plectorrhiza tridentata usually grows on trees in humid places such as deep gullies and swamps. It is found in from the Daintree area in Queensland south along the coast and nearby ranges of New South Wales to rainforest east of the Snowy River in north-eastern Victoria.