Common name: Spider Orchid
Caladenia arenaria Fitzg. APNI*
Synonyms: Arachnorchis arenaria (Fitzg.) D.L.Jones & M.A.Clem. APNI*
Description: Terrestrial herb.
Leaf linear to ± lanceolate, to 15 cm long and 18 mm wide, densely hairy on both surfaces and reddish at base.
Inflorescence to 40 cm high, rarely > 2-flowered, hairy. Sepals and lateral petals to 8 cm long, creamy white to yellowish grey growing increasingly dark and hairy towards tails; tails filamentous, dark, and hairy, up to half the length of the segments; tails of lateral petals and lateral sepals held horizontally or slightly drooping. Labellum ovate to cordate, c. 18 mm long and 10 mm wide, ± unlobed; margins with linear teeth to c. 3 mm long, becoming shorter and blunt towards apex. Central calli stalks short and stout, golfstick heads swelling to broadening but not conspicuously overlapping, in 4–6 rows
Distribution and occurrence: Grows in sclerophyll forest and on sandhills, usually under Callitris; south from Mudgee district.
NSW subdivisions: NC, CT, CWS, SWS, SWP
Other Australian states: Vic.
Threatened species: NSW BCA: Endangered; Commonwealth EPBC: Endangered
Collections from the Blue Mtns (CT), the Richmond R. (NC) and from Burrinjuck Dam and Carabost (SWS) have smaller labella with broader acute curved marginal teeth and are much closer to C. patersonii var. patersonii (Vic. & Tas. species).
Text by P. Bernhardt
Taxon concept: Flora of NSW 4 (1993)
APNI* Provides a link to the Australian Plant Name Index (hosted by the Australian National Botanic Gardens) for comprehensive bibliographic data
***The AVH map option provides a detailed interactive Australia wide distribution map drawn from collections held by all major Australian herbaria participating in the Australian Virtual Herbarium project.