Begonia adamsensis Magtoto & R. Rubite, 2018

Magtoto, Liezel M., Rubite, Rosario R. & Austria, Celia M., 2018, Begonia adamsensis (sect. Baryandra, Begoniaceae), a new species from Luzon Island, the Philippines, Phytotaxa 343 (3), pp. 289-292 : 290

Begonia adamsensis Magtoto & R. Rubite , sp. nov. ( Fig. 1 ).

Type: — PHILIPPINES. Ilocos Norte: Adams, elevation ca. 308 m, 18°26.108´N, 124°54.518´, March 2016, L. M. Magtoto et al. 242 (holotype NLUH)

Diagnosis:— Begonia adamsensis resembles B. hernandioides in having leaves that are peltate, with broad base, acuminate tip, nearly entire margin, and a glabrous peduncle; however, it differs significantly from B. hernandioides by its broadly ovate red stipule, pubescent petiole, elliptic peltate leaf, pubescent abaxial lamina, and 4 perianth segments in the carpellate flower.

Monoecious perennial rhizomatous herb. Rhizome green, prostrate, 8 cm long or more, ca. 1.5 cm diameter. Stipules persistent, 1–2 cm wide and 1.5–1.8 cm long, broadly ovate, red, apex mucronate. Leaves alternate; petiole 0.5–0.7 cm in diameter, 7–30 cm long, green, pink at base, sparsely pubescent with ca. 5 mm long brown hairs, inserted 2.5–7.5 cm from the basal margin; blade peltate, elliptic, ca. 6–16.5 cm wide and 12–27.5 cm long, apex acuminate, margin almost entire, adaxial lamina glabrous, abaxial lamina with brown hairs (ca. 4 mm long), basal veins (7–11) radiate. Inflorescences axillary, arising directly from the rhizome, dichasial cymes; peduncle 18–50 cm long, green, pink at base, glabrous, terete, dichotomously branched at the top. Bracts light pink, entire, boat-shaped, sheathing, caducous, ca. 0.5 cm long. Staminate flowers: pedicel ca. 1.5 cm long; perianth 4 segments, outer 2 orbicular, ca. 1 cm long and 1 cm wide, light pink, glabrous, inner 2 segments oblanceolate, ca. 4 mm wide and 6 mm long; anthers yellow. Carpellate flower: ca. 2.5 cm in diameter, pedicel ca. 2 cm long, ovary light pink, locules 3, placenta bilamellate, perianth segments 4, light pink, glabrous; outer 2 segments orbicular, ca. 1 cm wide and 1.5 cm long; smaller inner segment oblanceolate, ca. 0.5 cm wide and 1 cm long; larger inner segment obovate, ca. 0.8 cm wide and 1 cm long, folded; style three, stigma yellow. Capsule three-locular, ca. 1.5 cm long and 2 cm wide, broadly obovate, green, apex truncate, base rounded, wings 3, unequal, one wing nearly 1.5 cm wide, the other two 6–8 mm wide.

Etymology: —The species epithet is named after the locality, the Municipality of Adams, where the plant was found.

Distribution and habitat: — Begonia adamsensis is currently known only from the type locality. The plant grows on moist rocks and soil under shrubs and trees within 100-m area near a waterfall.

Phenology: —The plant flower between February and April.

Proposed IUCN category: — Begonia adamsensis is currently known from only one patch of 200 individuals in the 100-m area near the waterfall that is currently being developed as a tourist attraction. Following the IUCN Red List Criteria [CR, B2ab(iii)] ( IUCN 2012), Begonia adamsensis is hereby proposed to be classified as Critically Endangered.

Figures

FIGURE 1. Begonia adamsensis Magtoto & R. Rubite. A Habit; B. Rhizome; C. Stipule attached to rhizome; D. Stipule; E. Capsule; F. Cross section of capsule; G. Leaf adaxial and abaxial surface, tip, margin and veins; H. Hairs on leaf abaxial surface; I. Periole with hairs; J. Carpellate flower; K. Staminate flower. Scale bars = 10 mm. (All photographs taken by L.M. Magtoto).