Re-instatement of Pholidota sigmatochilus: an enigmatic species from Mt. Kinabalu, Sabah, Malaysia
Todd J. Barkman1 & Jeffrey J. Wood2
1Department of Botany, University of Texas, Austin, TX, U.S.A. 78713
2Orchid Herbarium, Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AE, U. K.
Re-instatement of Pholidota sigmatochilus J. J. Smith is proposed following an extensive study of material in the field and herbarium. Floral morphology places this taxon in Pholidota section Acanthoglossum. The longitudinal slit on the rostellum is especially distinctive. P. sigmatochilus is closely allied to P. clemensii Ames but differs by its thickened conduplicate leaves and much smaller stature. In addition, the lateral sepals do not clasp the labellum, which has shorter sides enclosing the hypochile, and the thickened column possesses a recessed anther and stigma. An illustration is provided which compares various features of P. sigmatochilus and P. clemensii. P. sigmatochilus is restricted to ultramafic substrates at elevations above 2000 meters and is probably endemic to Mt. Kinabalu and its satellite Mt. Tambuyukon, as comparable habitats are not found elsewhere in Sabah.