Begonia urubambensis Tebbitt

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 : 300-302

76. Begonia urubambensis Tebbitt

Figs 90B , 95

Edinburgh Journal of Botany 73 (1): 14 ( Tebbitt 2016).

– Type: PERU – Cusco Region: Prov. La Convención • Dist. Echarate, Kiteni y alrededores del margen izquierda del río Alto Urubamba ; 12°47′ S, 72°40′ W; 667 m a.s.l.; 2 Feb. 1989; P. Núñez & J. Arque 10092; holotype: CUZ ; isotypes: MO [ MO-1835948 ], US [ US00672877 ].

Etymology

When it was described, B. urubambensis was known from a single population surrounding the upper río Urubamba. It is named for its type locality.

Specimens examined

PERU – Ucayali Region: Prov. Atalaya • km 60 of road from Puerto Ocopa to Atalaya ; 10°54′10″ S, 74°08′19″ W; 718 m a.s.l.; 14 Feb. 2016; P.W. Moonlight & A. Daza 244; E [ E00885555 ], G, MO [ MO-3254778 ], MOL • ibid., km 89; 10°54′08″ S, 74°04′16″ W; 650 m a.s.l.; 14 Feb. 2016; P.W. Moonlight & A. Daza 246; E [ E00885559 ], MO [ MO-3254804 ], MOL • ibid., km 97; 10°53′52″ S, 74°00′57″ W; 598 m a.s.l.; 15 Feb. 2016; P.M. Moonlight & A. Daza 253; E [ E00885558 ], MO [ MO-3254782 ], MOL . – Cusco Region: Prov. La Convención • Dist. Echarate, roadside from 3–4 km south of Palma Real to Kiteni; 12°36′ S, 72°42′ W; 710 m a.s.l.; 6 Jan. 2015; M.C. Tebbitt & A. Daza 800ª; E [ E01059295 ], MOL, USM • río Manguriari (Manguyari) , alto Urubamba , río Manguriari ; 12°47′ S, 72°40′ W; 750 m a.s.l.; 2 Feb. 1991; P. Núñez & G. Ortíz 12802; USM • Dist. Echarate, San Antonio ; 12°39′18″ S, 72°55′09″ W; 1310 m a.s.l.; L. Valenzuela 6652; MO [ MO-2981119 ], US [ US00951222 ], USM • Dist. Echarate, Palma Real ; 12°56′31″ S, 72°46’58′ W; 850 m a.s.l.; I. Huamantupa 807; E [ E01007283 ].

Description

Acaulescent, rhizomatous herb, to 50 cm high. Rhizome ellipsoid, 1–8 × 1.5–2 cm, with 1 growing point. Stipules deciduous, narrowly-lanceolate to lanceolate, 3–5 × 1.5–2 mm, apex acute, translucent, white to pink, glabrous, margin entire, aciliate. Leaves 2–5, alternate, peltate; petiole 10–52 cm long, pale green, glabrous; blade subsymmetric, ovate-orbicular, to 25 × 23 cm, succulent, apex acuminate, base rounded, margin minutely-crenate, ciliate, upper surface mid-green, sparsely pilose, lower surface pale green, glabrous to sparsely pilose and densely pilose on the veins, veins peltate, 7–9 veined from the base. Inflorescences 1–2, bisexual, axillary, erect, an asymmetrical cyme, with up to 4 branches, bearing up to 15 staminate flowers and 10 pistillate flowers, protandrous; peduncle to 45 cm long, pale green, sparsely pubescent, bracts deciduous, elliptic to ovate, 5–12 × 2–6 mm, translucent, white to pink, glabrous, apex acute and short-apiculate, margin entire, aciliate. Staminate flowers: pedicels to 15 mm long, glabrous; tepals 4, spreading, outer 2 broadly-ovate or broadly-elliptic, 7–13 × 5–11 mm, apex obtuse to rounded, white, glabrous, margin entire, aciliate, inner 2 elliptic, 5–13 × 2.5–5.5 mm, apex obtuse, white, glabrous, margin entire, aciliate; stamens 35–50, spreading, yellow, filaments 1.5–3 mm long, free, anthers globose, 0.5–0.75 × 0.5–0.75 mm, dehiscing via lateral slits, connectives not extended, symmetrically basifixed. Pistillate flowers: pedicels to 25 mm long; bracteoles lacking; tepals 5, subequal, persistent in fruit, spreading, elliptic to ovate, 4–10 × 2–4.5 mm, apex obtuse, white, glabrous, margin entire, aciliate; ovary body ellipsoid, 4–7 × 3–5 mm, white, glabrous, unequally 3-winged, wings triangular, largest 5–9 × 5–10 mm, smallest ca 4–7 × 2–4 mm; 3-locular, placentae branches divided, bearing ovules on both surfaces; styles 3, yellow, free, 3–4 mm long, once-divided, stigmatic papillae in a spirally-twisted band. Fruiting pedicel to 35 mm long. Fruit a capsule, body ellipsoid to spheroid, to 10 × 8.5 mm, drying brown, wings same shape as in ovary, the largest expanding to 15 × 20 mm, the smallest expanding to 10 × 8 mm.

Proposed conservation assessment

Assessed by Tebbitt (2016) as Vulnerable (VU D2) based upon the species’ single known locality and pressures from land use change. Since then, we have collected the species from an additional population along the road to Atalaya , Ucayali Region. The species is highly abundant along a 15 km stretch of road, and the population appeared stable in 2016. We assess the species as Vulnerable (VU B1ab(iii)) due to its EOO of <10 000 km 2, two known localities, and the pressures of land use change at the type locality.

Identification notes

Begonia urubambensis is one of three terrestrial species of Peruvian Begonia with large (> 15 × 10 cm), peltate leaves. The other two species are B. acerifolia and B. serotina . It can be distinguished from both of these species because it lacks an aerial stem and also because its inflorescence is an asymmetrical cyme. It can also be distinguished from B. acerifolia because its leaves lack lobes (the leaves of B. acerifolia always have at least three triangular lobes).

Distribution and ecology

Endemic to Peru and known from Cuzco and Ucayali Regions ( Fig. 89B ). Found in semi-deciduous and Amazonian forest and at an elevation of 598–1310 m a.s.l. Begonia urubambensis has been collected on humid, shaded roadside or riverside banks. The species is rhizomatous and may die back to its rhizomes in the dry season.

Excluded names

Figures

Fig. 90. Distribution of the Begonia sect. Ignota in Peru and surrounding countries. A. B. bifurcata L.B.Sm. & B.G.Schub. (red), B. erythrothrix Tebbitt & Moonlight (red), and B. occultata J.P.Allen & Moonlight sp. nov. (green). B. B. speculum Moonlight & Tebbitt (red), B. thyrsoidea Irmsch., and B. urubambensis Tebbitt (green). Black lines indicate country borders, grey lines indicate major administrative divisions, blue lines indicate rivers, and shading indicates elevation.

Fig. 95. Begonia urubambensisTebbitt. A. Habitat.B. Habit.C. Staminate flower, front view. D. Pistillate flower, side view. All photographs by P.W. Moonlight from P.W. Moonlight & A. Daza 246 in Atalaya Province, Ucayali Region.

Fig. 89. Begonia glabra Aubl. A. Habit. B. Stipule. C. Leaf, adaxial surface. D. Leaf, abaxial surface. E. Staminate flower, side view. F. Staminate flower, front view. G. Androecium, side view. H. Pistillate flower, side view. I. Pistillate flower, front view. J. Cross section of ovary. K. Pistils, side view. All photographs taken by D.A. Purvis in the living collections of the Royal Botanic Garden Edinburgh (Accession 20101699, of unknown origin).