Indigenous orchid Disa longipetala

Observations of the wire orchid or kapotjie, Disa longipetala (Lindl.) Bolus, from the Western Cape

by William Liltved

Recent fires across the clay foothills The genus Schizodium was also and wire-like inflorescence stems to of mountains edging the Breede River proposed by Lindley in 1838, who have irregular S-shaped bends at vari­ Valley near Wolseley in the Western described three of the six species (the ous points, and for the leaves to form Cape, resulted in an astonishingly col­ other three having been described ear­ a basal rosette at ground level. Leaves ourful and abundant spring flowering lier by Linnaeus and Thunberg, but of D. longipetala have crisped margins display of geophytes belonging to a wide in separate genera). In 1888, Bolus and those of D. bifida may be spotted range of plant families (see accompany­ elected to include these species in Disa, or variegated, with purple under­ ing box). Yet, in its mature state, the an approach that was not adopted surfaces. ~ dense, expansive stands of pallid-grey by subsequent botanists. However, it renosterbos Elytropappus rhinocero­ appears he was correct in his assump­ tis, mixed with fynbos plants such as tion, as current molecular research Protea repens, belie its exquisite spring­ by Benny Bytebier at the University of A list of geophyte genera and species time potential! One such plant was the Stellenbosch, shows Schizodium to be observed on the clay foothills of mountains intriguing little orchid, Disa longipetala firmly embedded in the genus Disa. The edging the Breede River Valley near (Lindl.) Bolus. most recent revision of Schizodium was Wolseley in the Western Cape Of the six orchid species belonging to by Peter Linder in 1981. The sectional Disa section Schizodium (Lindl.) Bolus, name, Schizodium is derived from the Iridaceae Moraea (especially of the Galaxia Disa longipetala is surely the most Greek, schizein = to split and eidos = and Homeria groups), Aristea, Geissorhiza, extraordinary. John Lindley, often cel­ resemblance: having a split appear­ Hesperantha, Watsonia, Babiana, Gladiolus ebrated as the 'Father of orchidology', ance, and possibly refers to the bifid Oxalidaceae Predominantly Oxalis described this distinctive little Cape (divided by a deep cleft into two parts) purpurea orchid in 1838, basing his description petals, the highly lobed lip or possibly Campanulaceae Cyphia bulbosa var. of Schizodium longipetalum on a Johann its unusual growth habit. Drege collection from 'Paarl mountain'. Disa longipetala, is the rarest spe­ bulbosa, C. subtubulata Then, in 1897, Rudolph Schlechter cies in section Schizodium (the species Colchicaceae Wurmbea, Onixotis applied the name Schizodium anten­ of which are commonly known by the Hyacinthaceae Predominantly Lachenalia nijerum to plants he had collected on names, wire orchid or kapotjie) and is orchioides the Piketberg and which were figured known only from a few scattered and Haemodoraceae Wachendorfia paniculata by Harry Bolus in 1896, in his first vol­ vulnerable populations in the Western Orchidaceae Bartholina burmaniana, ume of Orchids of South Afriea (leones Cape. The plants range from 70 mm to Disperis bolusiana subsp. bolusiana, D. Orchidearum Austro-Afrieanarum extra­ 200 mm tall and the flowers are sweetly capensis, D. circumflexa subsp. circumflexa, tropicarum). Although the name 'anten­ perfumed with a hint of vanilla. D. cucul/ata, D. vil/osa, Pterygodium alatum, nijerum' is perhaps more appropriate All six members of Disa section P catholicum, P platypetalum, P volucris, (due to the curious floral structure of Schizodium are confined to the Cape Corycium orobanchoides, Holothrix cernua, the plant, referred to below), Lindley's Floristic Region, and are characterized H. vil/osa, Disa longipetala, D. physodes, D. earlier name, 'longipetala', according by a most peculiar, basally erect, three to the rules of botanical nomenclature, lobed lip. The lip appears glandular in satyrioides, D. spathulata subsp. spathulata, has priority. The species name, longip­ some species and probably plays an D. tenel/a subsp. pusilla, Satyrium erectum, etala is derived from the Latin, longus important role as a landing platform S. bical/osum, S. bicorne, S. coriifolium, S. = long and petalum = a petal, referring for pollinators. Further peculiar fea­ humile and S. lupulinum. to the long, narrow, antenna-like proc­ tures of species in section Schizodium esses of the petals and lip. are the tendency for their glossy brown

194 December 2006 Veld&Flora LEFT: The wire orchid or kapotjie, Disa longipetala, from the Breede River Valley. This rare orchid, measures between 70 mm and 200 mm tall and is only known from afew scattered populations in the Western Cape. The flowers are sweetly perfumed with a hint of vanilla.

Watercolour by Fay Anderson.

Bot8oc link

The accompanying illustra­ tion is the most recent of Fay Anderson's watercolours to be produced for a forthcoming book The Cape Orchids by W. R. Ultved and S. D. Johnson. This exceptional publication, on the indigenous orchids of the Cape Floristic Region, is to be endorsed by the Botanical Society.

Further reading Linder, H. P. 1981. Taxonomic studies on the Disinae: 2. Arevision of the genus Schizodium Lind!. Journal of South African Botany 47, 339-371. Linder, H. P. and Kurzweil, H. 1999. Orchids of southern Africa. Balkema, Rotterdam.

December 2006 Veld&Flora