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| Begonia depressinerva Pranada, in Pranada, Luna, Mendez & Calapatia-Salvador, 2019. |
Abstract
A new peltate species of Begonia sect. Baryandra from Kidadayaig Falls, General Nakar, Quezon is described and illustrated here. The new species, B. depressinerva, is diagnosed against the morphologically similar B. tayabensis. The two species are similar by having rhizomatous stem, peltate, ovate leaf, and 5-tepalled pistillate flower, but the new species is remarkably different by having densely pilose, asymmetric leaf blade, densely pilose petiole that is inserted much closer to the basal margin, obtuse to subobtuse staminate flower outer tepal apex, and glandularly hairy ovary. B. depressinerva is proposed to be Vulnerable (VU) D1, following the guidelines of the IUCN.
Keywords: taxonomy, Philippine flora, Begonia tayabensis, Vulnerable, General Nakar, Eudicots
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| Begonia depressinerva Pranada, sp. nov. A. Bract; B. Stipule; C. Mature Capsule; D. Cross section of immature capsule; E. Stigma; F. Anther; G, G'. Pistillate flower, anterior and lateral views; H, H'. Staminate flower, anterior and lateral views; I. Habit. illustrated by Jero Christ P. Manulat. |
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| Begonia depressinerva Pranada, sp. nov. A. Habit and habitat; B & E. Rhizome and stipules; C. Inflorescence; D. Leaf, adaxial and abaxial surfaces; F. Petiole; G. Staminate flower; H. Staminate flower bud and bracts, showing pedicel covered in dense glandular hairs; I. Mature capsule; J. Cross section of immature capsule; K. Pistillate flower, posterior, anterior, and lateral views. All photos by M.A.K. Pranada. |
Begonia depressinerva Pranada, sp. nov.
Diagnosis:— B. depressinerva is most similar to B. tayabensis among the species of Begonia sect. Baryandra. Both are rhizomatous and have peltate, ovate leaf blades with entire to subentire margins and acuminate apices. However, the former is distinct by having a densely pilose and asymmetric lamina (vs. glabrous or with short hairs and symmetric, or almost); and a densely pilose petiole (vs. glabrous to sparsely hairy) that is inserted nearer to the basal margin (7–13 mm vs. 20–40 mm). For the inflorescence, Rubite (2010) reported that the peduncle of B. tayabensis has few hairs while Merrill (1918: 38) reported that it was “sparingly ciliate with short, pale, spreading, scattered hairs”, in the protologue. However, glandular hairs were observed in the peduncle and pedicel of the live plants found at Three Falls in Sta. Maria, Laguna (Fig. 3H). Notably, the presence of glandular hairs in the peduncle and pedicel is similar to B. depressinerva but it is rather sparse (vs. dense). Both species are similar in having dichasial cymes, 4-tepalled staminate flowers and 5-tepalled pistillate flowers. However, B. depressinerva is different by having elliptic to ovate staminate flower outer tepal (vs. elliptic-ovate to broadly obovate or almost circular) with obtuse to subobtuse apex (vs. rounded); fewer anthers (31–44 vs. 40–50); and ovary covered in glandular hairs (vs. glabrous).
Etymology:— The specific epithet, depressinerva, is derived from the Latin translations of “depression” and “nerve” which are depressio and nervus, respectively. It refers to the depressed primary and secondary veins forminga grooved leaf upper surface.
MC Andrew K. Pranada , Christine Joy S. Luna, Noe P. Mendez and Ma. Eleanor Calapatia-Salvador. 2019. Begonia depressinerva (sect. Baryandra, Begoniaceae), A New Species from Luzon Island, the Philippines. Phytotaxa. 425(3); 154–162. DOI: 10.11646/phytotaxa.425.3.5
