Carousel Spider Orchid
- Arachnorchis arenicola
- Calonemorchis arenicola
The Carousel Spider Orchid is one of the most magnificent Spider Orchids of Australia. Its large flowers with long, spreading to pendulous petals and sepals come in a wide range of colours from light cream to dark purple. The large, maroon-tipped labellum usually contains four rows of dark calli and numerous long, fine, neatly arranged fringe segments. The Carousel Spider Orchid is restricted to the Swan coastal plain in south-western WA, from Lake Clifton in the south to just north of Perth. It grows in sandy soils and is still reasonably common in remnant woodland across the Perth metropolitan area. The peak flowering period is early spring.
The Carousel Spider Orchid is easily confused with the very similar Tuart Spider Orchid (Caladenia georgei) which has a similar geographic range. Both species commonly form hybrids, in particular across the Perth metropolitan area. However, unlike the Tuart Spider Orchid, the Carousel Spider Orchid has clubbed petals which are often slightly broader and pendulous rather than stiffly held. In addition, the labellum is slightly smaller than that of the Tuart Spider Orchid, and the fringe segments are usually finer and more neatly lined up. Flower colour varies considerably in both species and therefore cannot be used as a criterion for identification.
Other similar-looking species include the King Spider Orchid (Caladenia pectinata) and the Blushing Spider Orchid (Caladenia lorea), both of which occur near Perth as well.