Recovering the Melblom's Spider-orchid

The Melblom's Spider-orchid (Caladenia hastata) is federally endangered and now restricted to a handful of populations in the far south west of Victoria. Formerly this species occurred across western Victoria and South Australia, but is now extinct in South Australia and the range of the species has substantially retracted in Victoria due to historic clearing of sites. 

This stunning orchid has a very interesting pollination system, like many of Australia's Spider-orchids the Melblom's Spider-orchid is pollinated by a process of sexually deceptive. The pollinator, a male thynnid wasp, is attracted by the clubs on the dorsal and lateral sepals of the flower. The clubs emit chemical compounds that mimic the female wasp, the male being duped and clearly suffering from poor eyesight mates with the labellum of the orchid, thus getting pollinia deposited on him in the act. When he is then duped by another orchid, pollination is effected.

The Royal Botanic Gardens Victoria in conjunction with the Australian Network for Plant Conservation with assistance from DELWP, WCMA, Parks Victoria, the Australasian Native Orchid Society, Deakin University and ALCOA/Portland Aluminium have been mapping sites for suitable re-introduction of the Melblom's Spider-orchid coinciding with the distribution of the pollinator. This important research will lead to more effective long term conservation of the Melblom's Spider-orchid.