Website of Tobias Westmeier - Nature - Orchids of Australia

Range of Caladenia williamsiae — Range of *Caladenia williamsiae*.

Williams’ Spider Orchid
Caladenia williamsiae Hopper & A.P.Br. 2001

Synonyms

Arachnorchis williamsiae (Hopper & A.P.Br. 2001) D.L.Jones & M.A.Clem. 2002
Calonemorchis williamsiae (Hopper & A.P.Br. 2001) Szlach. & Rutk. 2003

Notes

Williams’ Spider Orchid is one of the rarest orchids of Australia. It is currently known from only a few hundred plants growing in a single bushland reserve in the Wheatbelt region of WA. Its rarity presumably is the result of clearing of most of its former habitat for agriculture. The orchids usually grow in small groups in shrubland on top of lateritic ridges, flowering in late winter and early spring.

Compared to most other Spider Orchids of WA, Williams’ Spider Orchid is diminutive in size. The pale-yellow and red flowers measure just a few centimetres across and for that reason are extremely difficult to locate. Another reason is the orchids’ habit of growing underneath dense shrubs where they are often hidden from view. In fact, this orchid is so elusive that it was only discovered as recently as 1999 by nature enthusiast Judy Williams and named in her honour in 2001. While several potentially suitable areas of bushland have since been searched without success, it is still possible that undiscovered populations of Williams’ Spider Orchid may have survived in other parts of the Wheatbelt.