Begonia malindangensis Merr. (1912: 391)

Naive, Mark Arcebal K., Cababan, Mc Arthur L., Lubos, Lesley C. & Hughes, Mark, 2022, Taxonomy of the genus Begonia (Begoniaceae) in Mindanao, Philippines III: New insights into the morphology and distribution of Begonia malindangensis and B. mindanaensis, Phytotaxa 564 (2), pp. 265-272 : 266-268

Begonia malindangensis Merr. (1912: 391) .

Type :— PHILIPPINES. Mindanao, Province of Misamis, Mt. Malindang , in forests, elev. 1,800 m, May 1906, E.A. Mearns & W.I. Hutchinson 4563 (lectotype: P [ P01900667 -image seen!], designated here ; isolectotypes: B [ B1002238447 -image seen!, B100238446 -image seen!], BO [ BO1543401 -image seen!], NY [ NY00118652 -image seen!, NY00118653 -image seen!], P [ P01900665 -image seen!, P01900666-image seen!], SING [ SING0083326 -image seen!], US [ US00115381 -image seen!, US00130768 -image seen!, US00328479 - image seen!]). Fig. 1 .

Terrestrial, monoecious, herbaceous or suffrutescent plant, 20–40 cm tall. Stem dichotomously branching, erect or ascending, terete, maroon to greenish, 4–8 mm in diam., glabrous, nodes swollen, greenish maroon, internodes to ca. 9 cm long. Stipules not seen. Leaves alternate, ca. 15–20 per plant, subsessile; petiole 1–2 cm long, ca. 3 mm in diam., terete, succulent, glabrous, green to reddish; lamina asymmetrical, oblong-ovate to oblong-lanceolate, 10–13 × 3–5 cm, chartaceous, dull green adaxially, paler abaxially, glabrous on both sides, margin distantly, irregularly dentate, base asymmetrical, apex long acuminate to subcaudate; venation palmate, channeled, green to reddish adaxially, protruding, green to reddish abaxially, 5–6 majour lateral veins on both sides, branching dichotomously. Inflorescences terminal and/or axillary, unisexual, cymose, 2–5 cm long; peduncle 1 cm long, green, terete; bracts broadly ovate to lanceolate, 1.8–2.3 × 1.0 cm, chartaceous, glabrous, pale green to reddish green, margin entire, apex acute. Staminate flowers borne in groups of ca. 5, white to pinkish white; pedicel ca. 5 mm long, green, terete, glabrous; tepals 2, orbicular to reniform, glabrous, 10 × 8 mm, margin entire, apex obtusely rounded; stamens 30–40, golden yellow; anthers elliptic, 0.8–1.0 mm long, apex obtuse; filament 0.8–1.5 mm long. Pistillate flowers borne in pairs, white; pedicel 1.5–1.8 cm long, green, terete, glabrous; conspicuous bracteoles present subtending the ovary, bracteoles broadly concave, ovate to lanceolate, 16–20 × 10 mm, glabrous, light green, margin entire, apex acute; ovary trigonous-ellipsoid, subtended by 3 bracteoles, light green when young, crimson red when mature, glabrous, 8–9 × 6–7 mm (wings excluded), 3- locular, placentation axile, bilamellate; tepals 5, outer tepals broadly ovate, 8–12 × 6–7 mm, apex attenuate, inner tepals elliptic to obovate, 8–12 × 4–6 mm, apex attenuate; styles 3, 2–4 mm long, yellow orange, bifid, apically forked; stigmas spirally twisted, papillose all around. Infructescence pendulous, 3.5–4.0 cm long; pedicel 1.5–1.8 cm long; tepals deciduous; capsules borne in pairs, turbinate to trigonous-ellipsoid, glabrous, green when young, reddish green when mature, brown when dry, with 3 subequal rounded-triangular wings, 12–15 × 15–16 mm including wings.

Distribution:— Endemic to Mindanao, Philippines ( Fig. 2 ). The species is recorded from the provinces of Misamis Occidental (Mt. Malindang), Bukidnon (Mt. Kalatungan Range Natural Park, Mt. Kiamo), Davao del Sur (Todaya) and North Cotabato (Mt. Apo).

Habitat:— The species was found growing in montane forest in shaded places with damp soil in Mt. Kiamo at 1484 m altitude. In Mt. Kalatungan Range Natural Park, the species was found growing on a stone wall near the Baguik-ikan river at a deeply shaded locality on damp substrate.

Phenology:— Observed flowering and fruiting in the wild in the months April, May, June, July, November, and December.

Provisional conservation status:— Begonia malindangensis is assigned a provisional status of Least Concern (LC), following the Red List criteria of the IUCN Standards and Petitions Subcommittee (2019). There are four localities known for this species with a combined extent of occurrence (EOO) of 12,661 km 2. Some of the localities are in protected areas (viz. Mt. Malindang, Mt. Kalatungan Range Natural Park and Mt. Apo) and flowering individuals are not vulnerable to any human interference or collecting.

Additional specimens examined:— PHILIPPINES. Mindanao , Bukidnon, Valencia City, Mt. Kalatungan Range Natural Park, Lourdes , elev. 1604 m, 22 nd Nov. 2020, M.A. Cababan 2 (HNUL) ; Bukidnon, Malaybalay City, Kibalabag, Mt. Kiamo , elev. 1400 m, 25 April 2018, M.A.K. Naive s.n., photographic record ; Bukidnon, Mt. Camates , Jun.-Jul. 1920, M. Ramos & G. Edano 38594 (K) ; North Cotabato, Kidapawan City, Brgy. Ilomavis, Energy Development Corporation (EDC), Site H, Mount Apo Natural Park , 9 December 2012, P.B. Pelser & J.F. Barcelona DOL68027, photographic record .

Notes:— Merrill (1912) originally described Begonia malindangensis based on two type gatherings, one collected from Mt. Malindang in the Province of Misamis (E.A. Mearns & W.J. Hutchinson 4563) and the other from Mt. Apo in the District of Davao (Copeland 1284). We choose the most complete sheet of the former [P01900667] as the lectotype. The allied species B. merrittii from Luzon is noted as being “absolutely confined to the wet mossy forest” which is “above the altitudinal distribution of Pinus insularis ” ( Merrill 1912) , and it seems that B. malindangensis could be a vicariant sister species, being restricted to high montane habitats in the south of the Philippines. Both species share conspicuous bracteoles covering the ovary.

Figures

FIGURE 1. Begonia malindangensis Merr.A. Habit (inset:female flowers); B. Leaves, abaxial surface (above), adaxial surface below; C. Pistillate flowers; D. Bracteole; E. Cross section of the ovary; F. Staminate flower; G. Dried fruit. From MA Cababan 2. Photos by: MAK Naive (A, C, D, E) and P. Pelser & J. Barcelona (B, F, G).

FIGURE 2. Map showing the distribution of Begonia malindangensis and B. mindanaensis.