Dimorphorchis is a genus of flowering plants from the orchid family, Orchidaceae. It contains 9 species, which are native to Papua New Guinea, the Philippines, Indonesia, Malaysia, Solomon Islands, and Brunei. It is remarkable for its two flower morphs present on the same plant.
Description
Vegetative characteristics Its species are epiphytic, monopodial herbs with large, pendulous,Teoh, E. S., & Teoh, E. S. (2021). Dimorphorchis Rolfe. Orchid Species from Himalaya and Southeast Asia Vol. 1 (A-E), 465-470. spreading, or erect up to 200 cm long stems. The basal part of the stem bears roots.Pridgeon, A. M., Cribb, P. J., Chase, M. W., & Rasmussen, F. N. (2014). Genera Orchidacearum volume 6: Epidendroideae (Part 3). pp. 172–175. OUP Oxford. The distichously arranged, coriaceous, linear up to 70 cm long leaves have an unequally bilobed to acute apex. Generative characteristics The long, glabrous or pubescent,Zou, L. H., Huang, J. X., Zhang, G. Q., Liu, Z. J., & Zhuang, X. Y. (2015). A molecular phylogeny of Aeridinae (Orchidaceae: Epidendroideae) inferred from multiple nuclear and chloroplast regions. Molecular phylogenetics and evolution, 85, 247-254. pendent or erect, racemose or paniculate, up to 3 metres long inflorescences bear dimorphic (heteranthous) or not dimorphic, bisexual flowers.Hutton, R. (2011). Dimorphorchis – Borneo beauties. The New Zealand Internet Orchid Review, 16, 26. http://www.orchidcouncil.org.nz/wp-content/uploads/2023/03/Issue-16-final.pdf The 2-3 flowers closest to the base of the inflorescence are strongly fragrant, slightly smaller, and of a different colour compared to the rest of the flowers, which are unscented and have wavy petals. The four pollinia with an elliptic viscidium are grouped in two pairs. It is unknown how the genus is pollinated.
Taxonomy It was published by Robert Allen Rolfe in 1919The Orchid review (Vol. 27, Issues 321–322, p. 149). (1893). Orchid Review ltd.]. https://www.biodiversitylibrary.org/page/37102243Dimorphorchis Rolfe. (n.d.). International Plant Names Index. Retrieved December 2, 2024, from https://www.ipni.org/n/29278-1 with Dimorphorchis lowii (Benth. & Hook. f.) Rolfe as the type species.Missouri Botanical Garden. (n.d.-d). Dimorphorchis Rolfe. Tropicos. Retrieved December 2, 2024, from http://legacy.tropicos.org/Name/40031513 Species It has nine species: Dimorphorchis beccarii (Rchb.f.) Kocyan & Schuit. Dimorphorchis breviscapa (J.J.Sm.) Kocyan & Schuit. Dimorphorchis celebica (Schltr.) Ormerod Dimorphorchis graciliscapa (A.Lamb & Shim) P.J.Cribb Dimorphorchis lowii (Lindl.) Rolfe Dimorphorchis lyonii (Ames) Ormerod Dimorphorchis rohaniana (Rchb.f.) P.J.Cribb Dimorphorchis rossii Fowlie Dimorphorchis tenomensis (A.Lamb) P.J.Cribb Phylogenetic relationships Within the subtribe Aeridinae, it is the sistergroup to Thrixspermum.
Etymology The generic name Dimorphorchis references the characteristic two flower morphs preset within the same plant.
Ecology Habitat It can grow as a lithophyte or epiphyte in rainforests.Ormerod, P. (2013). A new, orange-flowered Dimorphorchis from Maluku, Indonesia. Malesian Orchid Journal, 12, 33-37.
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