#ThreatenedSpecies of the Week: Small Dragon Orchid (Caladenia barbarella)

This week’s Threatened Species of the Week is the Small Dragon Orchid (Caladenia barbarella). It is listed as Endangered. This species is eligible for listing as endangered under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) as the species’ geographic distribution is restricted and is precarious for its survival. The Small Dragon Orchid is also listed as Declared Rare Flora under the Western Australian Wildlife Conservation Act 1950 and is managed as endangered (according to IUCN criteria) by the Western Australian Government.

Threats affecting the Small Dragon Orchid include grazing, habitat degradation, weed infestations, population fragmentation, fire, and climate change.

The Small Dragon Orchid is a tuberous, terrestrial orchid growing from 8 to 25 cm high. It has a single leaf 3-6 mm wide and 3-8 cm long, which lies fairly close to the ground. The single flower is approximately 2 cm long and 2 cm broad. The green labellum has shining purple calli (glands) at its base and is covered in long purple hairs that attract the pollinators, male Thynnid wasps. Flowering occurs from late August to September.

The Small Dragon Orchid is endemic to Western Australia. The species is known from 14 populations, east and north-east of Kalbarri in the Geraldton Sandplains Interim Biogeographic Regionalisation of Australia (IBRA) bioregion. Based on surveys undertaken between 1983 and 2008, the estimated total number of mature individuals is approximately 490. The species’ extent of occurrence is estimated to be between 1,300 km² and 2,000 km².

The Small Dragon Orchid usually grows in small, dense clumps, consisting of two or three plants, in sandy loam or clay loam soil. The species generally occurs along seasonal creek lines and swamps, or more rarely on rocky ledges. The Small Dragon Orchid typically inhabits areas of dense heath or tall scrub of Melaleuca uncinata or Acacia spp., and grows alongside Brachysema aphylla and Hakea preissii.

Information Source: Government of Australia, Department of Environment and Department of Parks and Wildlife Western Australia

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