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| Begonia butuanensis Bucay, Tandang & K.F.Chung, in Bucay, Tandang, Chen, Rubite et Chung, 2025. |
Abstract
Begonia butuanensis, a new species of Begonia sect. Baryandra endemic in northeastern Mindanao is described. We compared it to another species endemic to southern Mindanao, B. copelandii. Both species have ciliate leaf margins, rounded outer tepals, and lanceolate inner tepals of staminate flowers. However, B. butuanensis is distinct in its smaller perianth size, triangular capsule lateral wing with subfalcate apex (vs. rectangular with subacute to truncate apex in B. copelandii), puberulous peduncles (vs. glabrous), and orbicular to slightly ovate lamina with rounded to obtuse apices (vs. ovate to orbicular lamina with obtuse to acuminate apex). The species is observed only from the type locality, and we recommend the species to be listed as Critically Endangered (CR) following the 2024 IUCN guidelines.
archipelago, Begoniaceae, big genera, Pleistocene Aggregate Island Complexes, Eudicots
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| Begonia butuanensis Bucay, Tandang & K.F.Chung. A. Stipules; B–C Staminate flower; D. Pistillate flower; E–F Capsule; G. Habit. Illustration by Danilo N. TANDANG. |
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| Begonia butuanensis Bucay, Tandang & K.F.Chung. A. Habitat; B. Habit; C. Rhizome; D. Stipules; E. Petiole and leaf abaxial side; F. Multiple leaf adaxial side variations; G. Leaf margins; H. Bracts; I–K Staminate flower (angled, front, back); L. Pistillate flower; M. Pistillate flower side view showing ovary; N. Subfalcate capsules. Photos by Danilo N. TANDANG and Mark Angelo C. BUCAY. |
Begonia butuanensis Bucay, Tandang & K.F.Chung, sp. nov.
§ Baryandra
Type:—PHILIPPINES. Mindanao, Province of Agusan del Norte, western portion of Butuan City, ..., ca. 65 masl, 15 August 2023, MAC Bucay & DN Tandang 0981 (holotype PNH, isotype HAST).
Diagnosis:—Begonia butuanensis was found in northern portion of Mindanao but resembles another Mindanao-endemic species, B.
copelandii found only in Mt. Apo, southern portion of the island. Both species have ciliated hairs in the leaf margins and abaxial
venation. Main difference is on the perianth size as B. butuanensis is comparatively smaller than that of B. copelandii’s distinct
big flowers. B. butuanensis also differs significantly on capsule’s lateral wing by having triangular shape with subfalcate apex (vs
rectangular with subacute to truncated apex), puberulous peduncles (vs glabrous), and generally orbicular to slightly ovate lamina
with rounded to obtuse apices (vs ovate with obtuse to acuminate apices).
Etymology:—The specific epithet, “butuanensis” is derived from the type locality, Butuan City, province of Agusan del Norte, Mindanao island.
Mark Angelo C. BUCAY, Danilo N. TANDANG, Hong-Wun CHEN, Rosario R. RUBITE, Kuo-Fang CHUNG. 2025. Morpho-anatomical Description of New Begonia Species (sect. Baryandra, Begoniaceae) from Butuan City, Mindanao Island, Philippines. Phytotaxa. 681(1); 102-108. DOI: doi.org/10.11646/phytotaxa.681.1.8