Arthrochilus prolixus
Arthrochilus prolixus, commonly known as wispy elbow orchid, is a flowering plant in the orchid family and is endemic to eastern Australia. It has a rosette of bluish green leaves at its base and up to twenty two pale green, insect-like flowers with dark reddish to purplish glands on its labellum.
Description
Arthrochilus prolixus is a terrestrial, perennial, deciduous, sympodial herb with an underground tuber which produces daughter tubers on the end of root-like stolons. It has a rosette of between two and six linear to lance-shaped leaves on a side branch at its base, each leaf long and wide. Between three and twenty two pale green, insect-like flowers long are borne on a flowering stem tall. The dorsal sepal is linear, long, about wide and partly wrapped around the base of the column. The lateral sepals are lance-shaped, long, about wide. The petals are linear, about long and wide. The lateral sepals and petals are turned back against the ovary. The labellum is about long, wide on a stalk or "claw" about long. There is an insect-like callus about long with dark reddish brown, hair-like glands in a central band. The tip of the callus is about wide with shiny black glands. The column is light green to whitish with purplish spots, strongly curved, with two pairs of curved wings. Flowering occurs from December to February.
Arthrochilus prolixus was first formally described in 1991 by David Jones from a specimen collected near Wauchope. The description was published in Australian Orchid Research. The specific epithet is a Latin word meaning "stretched out long", referring to the long labellum calli.
Distribution and habitat
The wispy elbow orchid grows with grass and shrubs in forest between Manly in New South Wales and south-eastern Queensland. The largest population is in the Bulahdelah district. One colony has established itself in rotting sawdust at a sawmill.
Ecology
As with other Arthrochilus orchids, A. prolixus is pollinated by male thynnid wasps of the genus Arthrothynnus although the species involved is not known. It also reproduces asexually by producing new tubers.