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| Habenaria diwata R.Bustam., J.Collantes & M.R.B.Altamirano, in Altamirano, Collantes et Bustamante, 2025. Gardens’ Bulletin Singapore. 77(1); |
ABSTRACT
A new species, Habenaria diwata R.Bustam., J.Collantes & M.R.B.Altamirano
(Orchidaceae: Orchidoideae), is described from Mount Malinao, Luzon Island, Philippines.
Habenaria diwata most closely resembles the Taiwanese species H. tsaiana T.P.Lin in having
bipartite petals with an entire posterior lobe and a tripartite labellum with an entire mid-lobe
and subdivided side lobes, but differs by its shorter lateral sepals (9–11 mm long vs 12.5–13.5
mm long in H. tsaiana), anterior petal lobes that are mostly entire, with the lower margin
lacerate or unequally bifid at the apex (vs subdivided into two segments), shorter labellum
base (1 mm vs 1.5–2 mm) and labellum side lobes subdivided into two filiform segments (vs
subdivided into three filiform segments). Differences of H. diwata from a similar Philippine
species, H. lingulosa Ames, are briefly discussed. This discovery raises the current number
of recognised Habenaria species in the Philippines to 22. Illustrations and information on its
distribution, habitat, phenology, and proposed conservation status are provided.
Keywords. Bicol Region, endemic, Habenaria sect. Medusaeformes, mossy forest, terrestrial
orchid
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| Habenaria diwata R.Bustam., J.Collantes & M.R.B.Altamirano. A. Flowering plant, upper part. B. Basal part showing stem and roots. C. Ventral view of perianth and column. D. Lateral view of flower. E. Dissected perianth with ventral view of sepals, petals and labellum. F. Floral Bract. G. Lateral view of column and ovary. H. Lateral view of spur. I. Ventral view of column. J. Pollinaria. From the holotype, PTI-SLP1 27. (Photos: J.P.R. Collantes) |
Habenaria diwata R.Bustam., J.Collantes & M.R.B.Altamirano, sp. nov.
Habenaria diwata most closely resembles the Taiwan endemic H. tsaiana T.P.Lin in its bipartite petals with an entire posterior lobe and a tripartite labellum with an entire midlobe and subdivided side lobes. Habenaria diwata differs by its shorter lateral sepals (9–11 mm long vs 12.5–13.5 mm long in H. tsaiana), anterior petal lobes that are mostly entire, lacerate or unequally bifid at the apex (vs subdivided into two segments), shorter labellum base (1 mm vs 1.5–2 mm), and labellum side lobes subdivided into two filiform segments (vs subdivided into three filiform segments). Detailed morphological differences between the species are presented in Table 1.
Etymology. The specific epithet refers to Philippine mythology and folklore deities who guard the natural world (Landa, 1968). The pale, whitish green flowers are reminiscent of the ghostly white female representations of diwata in popular culture, while the dormancy in its life cycle in turn echoes the ephemeral nature of these spiritual beings.
Altamirano, M.R.B., Collantes, J.P.R. & Bustamante, R.A.A. 2025. Habenaria diwata (Orchidaceae: Orchidoideae), A New Species from Mount Malinao, Albay Province, Luzon Island, Philippines. Gardens’ Bulletin Singapore. 77(1); 101 - 112.
