Arachnorchis D.L.Jones & M.A.Clem. is a terrestrial genus in the Orchidaceae family created in 2001 by DL Jones, MA Clements, IK Sharma, and AM Mackenzie in a paper entitled A new classification of Caladenia R.Br. (Orchidaceae). This paper was followed by many others, some in support, some suggesting subgenera status, and others advocating keeping these species in Caladenia. This genus was never widely accepted and further taxonomic work by MA Clements, CG Howard CG1, and JT Miller published in 2015 did not support recognition of this genus as previously proposed. Arachnorchis as proposed was characterized by tubers partially enclosed in a fibrous sheath with about 200 species endemic to Australia and primarily found in southern areas but the distribution ranged from coast to inland areas and into the mountains. Although most species grow in well-drained soil, some are found in soils wet or water logged in winter during their growing season. They are found in a variety of forested and shrubby habitats. The type species was Arachnorchis patersonii (R.Br.) D.L.Jones and M.A.Clem. Species in this genus were often referred to as Spider Orchids because of their spidery flowers that are green, white, pink, red, or yellow. The flowers in this group have long tapering segments, usually clubbed or trichome covered sepals, a fringed or toothed labellum, narrow leaves, or if without these features, at least the flowers not pink. In 2025 species are considered to be synonyms of Caladenia species and photos of them are shown on that wiki page.
More information on this genus can be found here.
Arachnorchis falcata (Nicholls) D.L.Jones & M.A.Clem. see Caladenia falcata (Nicholls) M.A.Clem. & Hopper.
Arachnorchis hirta (Lindl.). D.L.Jones & M.A.Clem. see Caladenia hirta Lindl.
Arachnorchis longicauda (Lindl.) D.L.Jones & M.A.Clem., see Caladenia longicauda Lindl.
Arachnorchis longiclavata (E.Coleman) D.L.Jones & M.A.Clem. see Caladenia longiclavata E.Coleman.
Arachnorchis reticulata (Fitzg.) D.L.Jones & M.A.Clem. see Caladenia reticulata Fitzg.
Arachnorchis tentaculata (Schldl.) D.L.Jones & M.A.Clem. see Caladenia tentaculata Schltdl.
See PBS wiki pages for these genera that have been split and included in Caladenia :
Cyanicula, Drakonorchis, Jonesiopsis, Petalochilus, Stegostyla