Begonia brevicordata L.B.Sm. & B.G.Schub.

Moonlight, Peter. W., Jara-Muñoz, Orlando A., Purvis, David A., Delves, Jay, Allen, Josh P. & Reynel, Carlos, 2023, The genus Begonia (Begoniaceae) in Peru, European Journal of Taxonomy 881, pp. 1-334 : 101-103

20. Begonia brevicordata L.B.Sm. & B.G.Schub.

Fig. 35B

Journal of the Washington Academy of Sciences 45 (4): 113 ( Smith & Schubert 1955).

– Type: PERU – Cusco Region: [Prov. Paucartambo] • Dist. Kosñipata, Santa Isabel ; [13°02′ S, 71°31′ W]; 1320 m a.s.l.; Dec. 1947; J.C. Vargas Calderón 6767; holotype: US [ US00115262 ]; isotypes: CUZ [ CUZ13845 ] .

Brako & Zarucchi (1993: 191); León & Monsalve (2006: 165).

Etymology

The epithet is derived from the Latin ‘ brevis ’ and ‘ cordata ’, meaning ‘shortly cordate’, referring to the subcordate leaf bases of the species.

Specimens examined

PERU – Cusco Region: Prov. Paucartambo • Dist. Kosñipata, Santa Isabel ; [13°02′ S, 71°31′ W]; 1200 m a.s.l.; 23–31 Jul. 1948; R. Scolnik 927; US [ US00222036 ] • Dist. Kosñipata, road from Paucartambo to Manu National Park; 13°04′ S, 71°33′ W; 1846 m a.s.l.; M.C. Tebbitt & A. Daza 822; E [ E01059293 ], MOL, USM .

Description

Caulescent, herb, to 40 cm high. Stem erect, rarely branching; internodes to 6 cm long, to 3 mm thick, succulent, green flushed red, glabrous to sparsely villous. Stipules deciduous, lanceolate, 8–11 × 1.5– 4 mm, apex acute, opaque, green flushed red, glabrous to sparsely villous, margin entire, aciliate. Leaves> 5 per stem, alternate, basifixed; petiole 1–4 cm long, green flushed red, glabrous; blade asymmetrical, broadly ovate, to 6.5 × 4.5 cm, succulent, apex short-acuminate, base truncate to short-cordate, margin irregularly serrate, ciliate, upper surface green, glabrous, lower surface green, glabrous, veins palmate but with one primary vein, 5–7 veined from the base, with 1–2 secondary veins on the larger side, 1–2 on the smaller side. Inflorescences 1–2 per stem, bisexual, axillary, erect, cymose, with 4 branches, bearing up to 4 staminate flowers and 4 pistillate flowers, protandrous; peduncle to 4 cm long, pale green to pink, glabrous, bracts deciduous, oblanceolate, 2–14 × 0.5–4 mm, translucent, pale green flushed red, glabrous, apex acute to rounded, margin entire, aciliate. Staminate flowers: pedicels to 11 mm long, glabrous; tepals 2, spreading, broadly ovate, 6–8 × 5–6 mm, apex acute, white, glabrous, margin entire, aciliate; stamens number unknown, spreading, yellow, filaments 1.5–2 mm long, free, anthers ellipsoid, ca 1 × 0.4 mm long, dehiscing via lateral slits, connectives not extended, symmetrically basifixed. Pistillate flowers: pedicels to 8 mm long; bracteoles 3, positioned directly beneath the ovary, ovate, 1.5– 2 × 0.5–1 mm, apex acute to acuminate, translucent, colour unknown, glabrous, margin entire, aciliate; tepals 5, subequal, deciduous in fruit, spreading, obovate to broadly obovate, 5–11 × 1.5–8 mm, apex acute to acuminate, white, glabrous, margin entire, aciliate; ovary body obdeltoid, 1.5–3 × 1–2.5 mm, white flushed pink, glabrous, unequally 3-winged, wings triangular, largest 1.5–3 × 1.5–2 mm, smallest rib-like 0.5–1 mm wide; 3-locular, placentae branches divided, bearing ovules on both surfaces; styles 3, yellow, free, 1.5–2 mm long, once-divided, stigmatic papillae in a spirally-twisted band. Fruiting pedicel to 14 mm long. Fruit body obdeltoid, to 8 × 5 mm, drying light brown, the largest wing expanding to a contorted, downward pointing band, to 8 × 10 mm, the smallest two rib-like, expanding to 2 mm wide.

Proposed conservation assessment

Previously assessed as Data Deficient by León & Monsalve (2006). Known from two localities in Cusco Region, with a combined EOO of <100 km 2. Within its range, it has a patchy distribution and is found in small populations in humid microhabitats. We assess B. brevicordata as Vulnerable (VU D2) due to its limited distribution.

Identification notes

Begonia brevicordata is the smallest member of the stenotepala group, reaching maturity at around 20–40 cm tall. It is distinct in its small (to 6.5 × 4.5 cm) broadly ovate leaves with a truncate or short-cordate base. It is also unusual within the group in its bracteoles with entire, aciliate margins.

Begonia brevicordata may also be confused with B. lophoptera , which is a similar sized species which often has broadly ovate leaves and is found in the same habitat. When flowering, it can be distinguished by its pistillate flowers with 5 tepals (vs 2) and its staminate flowers with tepals with an acute to acuminate apex. It can be distinguished when sterile by its glabrous petioles (vs sparsely to densely pilose).

Distribution and ecology

Endemic to Peru and Cusco Region ( Fig. 35B ), where it is found in lower and middle montane Forest at an elevation of 900–1856 m a.s.l. Begonia brevicordata is typically collected from small populations in permanently wet and shaded microhabitats within montane forests.

Figures

Fig. 35. Distribution of the stenotepala group of Begonia sect. Cyathocnemis (Klotzsch) A.DC. in Peru and surrounding countries. A. B. alto-peruviana A.DC. (red). B. B. brevicordata L.B.Sm. & B.G.Schub. (red), B. deltoidesMoonlight sp. nov. (blue), and B. lucifuga Irmsch (green). C. B. longitepalaMoonlight sp. nov. (red) and B. subspinulosa Irmsch. (blue). D. B. stenotepala L.B.Sm. & B.G.Schub. (red). Black lines indicate country borders, grey lines indicate major administrative divisions, blue lines indicate rivers, and shading indicates elevation.