Rosella Spider Orchid

There are currently less than 150 known Rosella Spider-orchid plants in the wild. The Rosella Spider-orchid (Caladenia rosella) grows to 20cm tall when flowering and has a single leaf which is 4-9cm long and covered with fine hairs.  The base of the leaf stem is greenish to reddish-purple coloured. Flowers are pink with a musky fragrance and blossoms from August to September.

Although the Rosella Spider-orchid was once scattered throughout Central Victoria, it is now only known from four populations that are restricted to Nillumbik Shire.

The Rosella Spider-orchid has been impacted from the clearance of habitat, rabbit grazing and grassy weeds. Grassy weeds such as Panic Veldt-grass and Quaking Grass smother the orchid and compete for nutrients and water. Other threats include housing developments and land clearing, predation by White-winged Choughs, inappropriate fire regimes and habitat disturbances. Loss of the key pollinator species, a bee of the Leioproctus genus, due to a reduction in the diversity of the orchid’s habitat, including the removal of indigenous daisies, wattles and peas, is also an important factor in the decline of the Rosella Spider-orchid.

The Rosella Spider Orchid is listed as endangered under the Federal Environment Protection and Biodiversity Conservation Act 1999. It is also endangered in Victoria and listed as threatened under the Flora and Fauna Guarantee Act 1988. These acts have helped to protect the remaining populations of Rosella Spider-orchid and recovery actions for this species are currently being undertaken including protecting populations with small metal cages, hand pollination and intensive weed control works.

A program to propogate these orchids is underway with help from the Royal Botanic Gardens, Melbourne.