Black-clubbed Spider-orchid  |  

Caladenia atroclavia, Family Orchidaceae, also known as Black-clubbed Spider Orchid, is a hirsute terrestrial herb with leaves 8Ð12 cm long and 5Ð10 mm wide. Basal leaves are irregularly blotched red-purple and inflorescences grow 25Ð35 cm tall. Flowers are usually solitary, pale greenish-cream in colour with red suffusions on the petals. Petals have prominently thickened dark black-purple clubs. Flowering occurs in October and the flowerÕs fragrance resembles an overheated electric motor (Jones & Clements, 1988; Jones, 2006). Although C. atroclavia has been called Arachnorchis atroclavia (Jones, 2006), the latter species is considered a synonym of the former in the Australian Plant Census (see CPBR,
2008). C. atroclavia has been confused with C. fitzgeraldii and to a lesser extent C. reticulata
but is distinguishable by the very prominent, much longer, dark terminal osmopores on the sepals (Jones & Clements, 1988; Jones, 2006).