Begonia aeranthos L. B. Sm. & B. G. Schub.
Creators: name: Moonlight, Peter. W.
name: Jara-Muñoz, Orlando A.
name: Purvis, David A.
name: Delves, Jay
name: Allen, Josh P.
name: Reynel, Carlos
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Cucurbitales
Begoniaceae
Begonia
Begonia aeranthos

description: 41. Begonia aeranthos L.B.Sm. & B.G.Schub.
Fig. 57A
Memoirs of the New York Botanical Garden 8 (1): 36 (Smith & Schubert 1952).
– Type: ECUADOR – Prov. Santiago-Zamora • “oriente”, Cordillera Cutucú; ca 2°40′ S, 78°W; 1370–1675 m a.s.l.; 17 Nov.–5 Dec. 1944; W.H. Camp E-1317; holotype: NY [NY00112289].
Smith & Wasshausen (1979: 239, 1986: 15); Brako & Zarucchi (1993: 191); Vásquez et al. (2005: 112–125); Quintana & León-Yáñez (2011: 197); Tebbitt & Pérez (in press).
Begonia grandibracteolata Irmsch., Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie 76 (1): 91 (Irmscher 1953).
– Type: PERU • W. Lobb s.n.; holotype: W.
Etymology
The name is derived from the Greek words ‘ aérios ’ and ‘ anthos ’ meaning ‘aloft’ and ‘flower’. This refers to the species’ epiphytic habit of the species.
Specimens examined
PERU – Huánuco Region • SW slope of the río Ilulla Pichis watershed, on the ascent of Cerros del Sira, in valley-canyon on the way to waterfall just below camp 4 (Peligroso); 9°25′ S, 74°44′ W; 1500 m a.s.l.; 22 Jul. 1969; T.R. Dudley 13115; US [US01925936]. – Prov. Leoncio Prado • Dist. Hermillo Valdizán, La Divisora, near top of divide between Huallaya and Aguaytía drainages, border with Loreto; 9°09′56″ S, 75°47′31″ W; 1630 m a.s.l.; 29 Mar. 1977; A.H. Gentry, D.C. Daly & S. Cruz 18892; MO [MO-1642606] • ibid.; A.H. Gentry, D.C. Daly & S. Cruz 18892ª; MO [MO-1643492] • ibid.; 1500–1600 m a.s.l.; 21 Jun. 1976; J. Schunke V. 9321; F, MO [2: MO-1643515, MO-2154630], US [2: US00672824, US01925934] • ibid.; 9°09′24″ S, 75°47′31″ W; 1500–1600 m a.s.l.; J. Schunke V. 11435; MO [MO-2216361]. – Pasco Region: Prov. Oxapampa • Dist. Pozuzo, Parque Nacional Yanachaga-Chemillén, Sector Huampal, Microcuenca Quebrada Onda; 10°11′01″ S, 75°39′13″ W; 1172 m a.s.l.; 11 May 2011; A. Arapa & D. Mateo 4; HOXA, MO [2: MO-2648700, MO-2648701], USM. – Ucayali Region: Prov. Coronel Portillo • Dist. Iparía, falda dento las cuencas del río Ariapo y río Iparía, afluentes del río Ucayali, Reserva Comunal el Sira; 9°27.85”S, 74°33.95”W; 1550–1600 m a.s.l.; 3 Nov. 2009; J.G. Graham 5213; MOL, US [US01088860].
Description
Caulescent, lianescent herb, to 6 m high. Stem repent, branching; internodes to at least 12 cm long, to 3 mm thick, succulent, appearing woody at the base, brown to red, glabrous. Stipules persistent, lanceolate to ovate, 6–12 × 2–6 mm, apex acute, opaque, brown, glabrous, margin entire, aciliate. Leaves> 5 per stem, alternate, minutely peltate; petiole 4–20 cm long, red, glabrous; blade subsymmetric, elliptic to ovate, to 24 × 11 cm, succulent, apex acuminate, base truncate to rounded, margin denticulate to serrate, ciliate, upper surface green, glabrous, lower surface green, glabrous, veins peltate, 6–7 veined from the base. Inflorescences 1–3 per stem, unisexual, axillary, pendulous, cymose, with 5 branches, bearing up to 16 staminate flowers or 16 pistillate flowers; peduncle to 13 cm long, red, glabrous, bracts deciduous, lanceolate, 6–14 × 2–4 mm, opaque, red, glabrous, apex acute, margin entire, aciliate. Staminate flowers: pedicels to 25 mm long, glabrous; tepals 4, projecting, outer 2 oblong to lanceolate, 18–20 × 6–7 mm, truncate, red, glabrous, margin entire, aciliate, inner 2 lanceolate, ca 11 × 5 mm, apex acute, red, glabrous, margin entire, aciliate; stamens 6, projecting, yellow, filaments 0.8–1 mm long, fused into an irregularly branching column to 5 mm long, anthers narrowly ovoid, ca 3 × 1 mm, dehiscing via lateral slits, connectives projecting, symmetrically basifixed. Pistillate flowers: pedicels to 25 mm long; bracteoles 2, positioned directly beneath the ovary, elliptic to ovate, 10–12 × 4–6 mm, apex acute, opaque, red, glabrous, margin entire, aciliate; tepals 5, subequal, late deciduous in fruit, projecting, elliptic, 10–17 × 4–12 mm, apex acute to acuminate, red, glabrous, margin entire, aciliate; ovary body ovoid to globose, 8–12 × 4–12 mm, red, glabrous, unequally 3-winged, largest triangular, ascending, 9–20 × 7–12 mm, smallest rib-like to semi-circular, 9–20 × 2.5–5 mm; 3-locular, placentae unknown; styles 3, yellow, fused at the base, 5–12 mm long, reniform, stigmatic papillae in a spirally-twisted band. Fruiting pedicel to 25 mm long. Fruit body globose, to 15 × 15 mm, drying brown, wings same shape as in ovary, the largest expanding to 27 × 20 mm, the smallest to 20 × 5 mm.
Proposed conservation assessment
Assessed by Quintana & León-Yáñez (2011) as Endangered (EN B1ab(iii)). At this point, the species was known only from the type locality where it had not been collected since 1952. We cite specimens from four localities but despite extensive searches in 2016, were unable to locate the species during fieldwork at the two localities we visited. We assess B. aeranthos as Endangered (EN B2ab(iv)).
Identification notes
Begonia aeranthos is easily recognised as the only climbing species of Peruvian Begonia with peltate leaves with a petiole insertion <⅕ of the length along the leaf. All Peruvian collections of B. aeranthos were previously identified as B. glabra, which is a superficially similar but not peltate species. The flowers of these species are very different, with B. glabra having relatively small, white flowers and B. aeranthos having large, red flowers.
Distribution and ecology
Known from Ecuador and Peru. Within Peru it has been collected in Huánuco, Pasco, and Ucayali Regions (Fig. 57A). Found in lower montane forest at an elevation of 1170–1600 m a.s.l. where it grows as an epiphyte. Its vivid red, pendulous flowers suggest B. aeranthos is pollinated by hummingbirds. Extensive fieldwork in both the Huánuco and Pasco populations in 2016 failed to locate B. aeranthos, which leads us to believe it is either rare or usually an epiphyte in very tall trees.
description: Published as part of Moonlight, Peter. W., Jara-Muñoz, Orlando A., Purvis, David A., Delves, Jay, Allen, Josh P. & Reynel, Carlos, 2023, The genus Begonia (Begoniaceae) in Peru, pp. 1-334 in European Journal of Taxonomy 881 on pages 181-182, DOI: 10.5852/ejt.2023.881.2175, http://zenodo.org/record/8178280