Begonia caramoanensis Rubite, Irabagon, Palacio, Y.P.Ang, R.Bustam., 2020

Rubite, Rosario R., Irabagon, Madeleine L., Palacio, Diane Joy E., Ang, Yu Pin & Bustamante, Rene Alfred Anton, 2020, Begonia caramoanensis (sect. Baryandra, Begoniaceae) a new species from Camarines Sur, Philippines, Phytotaxa 439 (3), pp. 287-294 : 291-293

publication ID	https://doi.org/ 10.11646/phytotaxa.439.3.10
persistent identifier	https://treatment.plazi.org/id/03CF87E7-FFD9-304A-FF6E-F8BAFCBEFAF4
treatment provided by	Felipe
scientific name	Begonia caramoanensis Rubite, Irabagon, Palacio, Y.P.Ang, R.Bustam.
status	sp. nov.

Treatment

Begonia caramoanensis Rubite, Irabagon, Palacio, Y.P.Ang, R.Bustam. View in CoL sp. nov.

sect. Baryandra

Type:— PHILIPPINES. Luzon Island: Province of Camarines Sur, Municipality of Caramoan, Barangay Caputatan, moist rocks under trees and shrubs, elevation ca. 30 m, 13°45’44”N, 123°52’6”E, 2 November, 2018, R. R. Rubite 988 (holotype PNH). Fig. 2–3 View FIGURE 2 View FIGURE 3 .

Monoecious perennial rhizomatous herbs. Rhizom e dark green to maroon to brown, 4 to 16 cm long, 10–16 mm thick, subglabrous, internodes 4–8 mm long. Stipules ovate, green to pink to brown, apex aristate, 7–19 × 5–14 mm, with prominent pink to red keel and with tuft of pink hairs (6–10 mm long) on the abaxial side. Leaves alternate; petiole, green to maroon to brown, terete, 12–26 cm long and 4–8 mm thick, tomentose (0.5–2.0 mm green to brown hairs); blade mostly obliquely rounded some obliquely wide ovate, 8–11 × 8–12 cm, adaxial lamina dark green to maroon, glabrous, abaxial lamina light green to maroon with prominently raised veins, pilose with light green to maroon hispid (0.5–1 mm long), denser on the veins, margin shallowly undulate almost entire, ciliate; base cordate, lobes rounded, apex obliquely rounded to slightly acute, venation palmate, primary veins 9–10. Inflorescence axillary, arising directly from the rhizome, dichotomously branched ca. five times; peduncle light green to maroon to brown 10–25 cm long and 2–5 mm thick, erect, with white to green to brown glandular hairs (0.5–2 mm) varying from sparse to dense. Bracts boat-shaped, pink to maroon 4–5 × 5–6 mm, with white to green to brown glandular hairs (0.5–1 mm), bracteoles pink to maroon, densely covered with glandular hairs, boat-shaped, 2.5–4 × 4–5 mm in staminate flower and ovate, 2–2.5 × 3–4 mm in pistillate flower. Staminate flower: pedicel light green to maroon, erect to ascending, 3–18 mm with pinkish to green glandular hairs (0.5–1 mm) varying from sparse to dense; corolla 15–20 × 12–18 mm; tepals 2+2, white, glabrous, outer pair orbicular to oblong 7–9 × 7–8 mm, inner pair oblanceolate 5–8 × 2–3 mm, adaxial side of both outer and inner tepals white, while abaxial side pinkish, androecium actinomorphic, stamens 25–30, filaments 1 mm long, shortly united at the base; anthers yellow, oblong, 1 mm long. Pistillate flower: pedicel green to pink, ascending at the beginning then later recurving downwards, 9–10 mm with pinkish to green glandular hairs (0.5–1 mm), varying from sparse to dense; corolla 14–16 × 13–15 mm; tepals 2+3, outer pair orbicular 6–7 × 6–7 mm; pinkish abaxial and white adaxial, 3 inner tepals white, asymmetrical, 6–9 × 2–5 mm; ovary pinkish green, oblong 4–7 × 3–4 mm (wings excluded), wings 3, unequal, 6–10 mm long, lateral wings, narrowly crescent-shaped, 3–6 mm wide, abaxial wing much protruded, crescent-shaped, acute or rounded at proximal, truncate at distal, 8–14 mm wide, ovary and wings with pinkish glandular hairs (0.5–1 mm), tri-locular, placentae axile, bifid; styles three, 2–4 mm long, stigma yellow, spirally twisted and papillose all around. Capsule pendent, glabrous, recurved such that the largest wing is facing downwards, 6–12 × 14–22 mm, obliquely rounded to sub-rhomboid in outline.

Diagnostic characters:— The long glandular hairs on the bracts, peduncle, pedicels and ovary of B. caramoanensis is a rare character in the members of section Baryandra . It is shared with two other Philippine species, B. droseroides Rubite et al. (2018: 201) and B. palemlemensis Calaramo et al. (2019: 36) . B. caramoanensis is distinguished from B. droseroides by its suborbicular (vs. oblique, widely ovate) and larger leaves with 8–11 × 8–12 cm (vs. 5.4−8.2 × 4.4–7 cm); smaller staminate flowers with outer tepals 7–9 × 7–8 mm (vs. 11–16 × 10–17 mm), inner tepals 5–8 × 2–3 mm (vs. 9–17 × 3–6 mm) and 25–30 stamens (vs. 34–43). B. caramoanensis is differentiated from B. palemlemensis by its subglabrous rhizome (vs. densely pilose); suborbicular (vs. widely ovate) and smaller leaves with 8–11 × 8–12 cm (vs. 9−14 × 7–9 cm); smaller staminate flowers with outer tepals 7–9 × 7–8 mm (vs. 8–10 × 8–10 mm), inner tepals 5–8 × 2–3 mm (vs. 9–12 × 3–6 mm) and 25–30 stamens (vs. 47–60).

Etymology:— The species epithet is named after the type locality.

Distribution and Habitat:— The plants grow abundantly on moist rocks under trees and shrubs over limestone forests together with other herbaceous plants like Impatiens sp. and Elatostema sp.

Conservation Status:— About 500 to 700 individuals, was observed in each of the four barangays of Caramoan, thus according to to the IUCN red list categories and criteria ( IUCN 2012), B. caramoanensis is hereby proposed to be placed under Least Concern (LC) category.

Begonia caramoanensis is the latest addition to the growing number of Philippine Begonia sect. Baryandra , which now includes 73 species worldwide (Hughes et al. 2015–). The province of Camarines Sur is now the home of two endemic begonias, B. caramoanensis and B. madulidii . The researchers recommend the consideration of these species as icons of conservation at the Caramoan National Park.