Arachnis, abbreviated as Arach. in horticultural trade, is a genus of the Orchid family (Orchidaceae).
Plants are distributed from Indo-China, Malaysia, to the Solomon Islands.
This genus has long scrambling stems and fleshy flowers. Flowers have a fixed lip and four pollina. The genus contains around seven species.
Plants are best grown hanged in baskets and on mounted and usually require full sunlight and intermediate to warm temperatures. If hunged or mounted on cork, the roots must be watered frequently and if it is potted in bark they should be watered 1 to 2 times a week. Plants should be grown in media that is kept moist but not wet such as several pieces of medium to coarse fir bark, or sphagnum moss. Water evenly and fertilize heavily year round. Keep plants in a area with high humidity.
This genus is named after its spider shaped flowers. It is commonly referred to as “scorpian orchids.”
- Arachnis annamensis (Rolfe) J.J.Sm.,1912.
- Arachnis beccarii Rchb.f., 1886.
- Arachnis beccarii var. beccarii.
- Arachnis beccarii var. imthurnii (Rolfe) K.W.Tan, 1974.
- Arachnis breviscapa (J.J.Sm.) J.J.Sm., 1912.
- Arachnis celebica (Schltr.) J.J.Sm., 1912.
- Arachnis flos-aeris (L.) Rchb.f., 1886.
- Arachnis flos-aeris var. flos-aeris.
- Arachnis flos-aeris var. gracilis 1935.
- Arachnis grandisepala J.J.Wood, 1981.
- Arachnis hookeriana (Rchb.f.) Rchb.f., 1886.
- Arachnis labrosa (Lindl. & Paxton) Rchb.f., 1886.
- Arachnis limax Seidenf., 1970.
- Arachnis longicaulis (Schltr.) L.O.Williams, 1937.
- Arachnis longisepala (J.J.Wood) Shim, Soón & A.L.Lamb, 1982.
- Arachnis × maingayi (Hook.f.) Schltr., 1911 (A. flos-aeris × A. hookeriana)