Begonia longinqua Moonlight, 2023

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 : 90-92

15. Begonia longinqua Moonlight sp. nov.

urn:lsid:ipni.org:names:77323289-1

Fig. 32

Diagnosis

Most similar to B. bracteosa but differs in its persistent (vs deciduous) stipules; inflorescences that branch three times and bear up to twelve flowers (vs up to six times with> 20 flowers); its 8–14 (vs> 20) stamens; and the presence of a large, persistent bracteole at the base of the ovary and fruit (vs no bracteole).

Etymology

The name derives from the Latin ‘ longinquum ’, meaning ‘remote’, and refers to the isolated nature of the species’ two known populations.

Type

PERU – Ucayali Region: Prov. Coronel Portillo • Dist. Callaria, Cuenca del río Utiquinia , Cabecera de la quebrada Espejoyacu , afluente de la quebrada Manuela, Cerro Espajoyacu; 7°57.81′ S, 73°53.98′ W; 800 m a.s.l.; 7 Mar. 2003; J.G. Graham 2390; holotype: USM; isotypes: F [ V0088041F ], G, US [ US01008545 ] .

Specimens examined

COLOMBIA – Dept. Caquetá • Mun. Florencia, Vereda El Canelo , Finca Cataluña . Margen izquierdo del río Orteguaza . Fragmento de bosque (15 ha) en matriz de potreros; 1°29′58.7″ N, 75°31′16.6″ W; 330 m a.s.l.; 30 Jan. 2002; C. Marín, M. Correa, J. Díaz & D. Caicedo 2485; COAH .

Description

Caulescent herb, to 30 cm high. Stem erect, rarely branching; internodes to 6.5 cm long, to 5 mm thick, succulent, pale green, glabrous. Stipules persistent, lanceolate, 15–22 × 7–12 mm, apex acute to obtuse, translucent, pale green, glabrous, margin entire, aciliate. Leaves 3–5 per stem, alternate, basifixed; petiole 3–7 cm long, pale green flushed pink, glabrous; blade asymmetrical, ovate, to 13 × 9 cm, succulent, apex acuminate, base cordate, basal lobes not overlapping, sinus to 15 mm deep, margin entire to serrulate, sparsely long-ciliate, upper surface green, glabrous, lower surface pale green, glabrous, veins palmate but with one major vein, 8–10 veined from the base, with 1–2 veins on the broader side of the blade, 1–2 on the narrower side. Inflorescences 1–3 per stem, bisexual, axillary, erect, cymose, with up to 2 branches, bearing up to 6 staminate flowers and 6 pistillate flowers, protandrous; peduncle to 12 cm long, pale green flushed pink, glabrous, bracts deciduous, ovate, ca 5 × 2 mm, translucent, colour unknown, apex acute, margin entire, aciliate. Staminate flowers: pedicels to 14 mm long, glabrous; tepals 2, spreading, ovate, 10–12 × 8–13 mm, apex rounded, pink, glabrous, margin entire, aciliate; stamens 8–14, spreading, yellow, filaments 1–2 mm long, free, anthers elliptic, 1–2 × 0.5–0.8 mm long, dehiscing via lateral slits, connectives extended to 0.2 mm, symmetrically basifixed. Pistillate flowers: pedicels to 15 mm long; bracteoles 1, positioned directly beneath the ovary, lanceolate, 10–15 × 2.5– 4 mm, apex rounded, translucent, colour unknown, glabrous, margin entire, ciliate; tepals 2, equal, deciduous in fruit, projecting, narrowly-ovate, 10–15 × 4–6 mm, apex obtuse, pink, glabrous, margin entire, aciliate; ovary body ovoid, 4–6 × 3–4 mm, colour unknown, glabrous, unequally 3-winged, the largest wing triangular, ascending, ca 9 × 5 mm, smallest marginal ca 1 mm wide; 3-locular, placentae unknown; styles 3, yellow, free, ca 4 mm long, once-divided, stigmatic papillae in a spirally twisted band. Fruiting pedicel to 23 mm long. Fruit body ovoid, to 13 × 10 mm, drying brown, the largest wing same shape as in ovary, expanding to 16 × 23 mm, the smallest expanding to an ascending triangular wing, to 16 × 10 mm.

Proposed conservation assessment

Known from two collections made ca 1000 km apart in Amazonian Peru and Colombia. The Colombian locality is largely deforested but the Peruvian locality is in an extremely remote part of the Amazon rainforest protected by Parque Nacional Sierra del Divisor. No information is known about the size of these populations, and it is unlikely the species is restricted to these two localities given the abundance of similar habitats on the margins of the Peruvian, Ecuadorian and Colombian Andes. We assess B. longinqua sp. nov. as Data Deficient (DD).

Identification notes

Begonia longinqua sp. nov. resembles a more compact, more succulent version of the widespread species B. bracteosa , to which it is almost certainly most closely related. It is easily recognised when in flower by its smaller, fewer branched inflorescences (branching 3 times vs up to 6 times) and its staminate flowers with 8–14 stamens (vs 20–50 stamens). It also differs in its persistent stipules.

Distribution and ecology

Begonia longinqua sp. nov. is known from two collections made ca 1000 km apart. The type collection was made at the summit of Cerro El Cono (also known as Cerro Espejoyacu) in the Sierra del Divisior in Loreto Province Peru ( Fig. 24B ). The second collection was made in Caquetá Department, Colombia, close to the town of Florencia. Both collection localities are on small hills that represent islands of lower montane forest surrounded by lowland Amazonian forest.

Figures

Fig. 32. Begonia longinqua Moonlight sp. nov. A. Habit. B. Staminate flower, front view. C. Staminate flower, side view. D. Fruit, side view. Illustration by Anna Dorward from J.G. Graham 2390 (US).

Fig. 24. Distribution ofBegonia sect.Cyathocnemis (Klotzsch)A.DC. in Peru and surrounding countries. A. B. amoeboides Moonlight (red) andB. imbrexiformis Moonlight sp. nov. (blue).B. B. bracteosaA.DC. (red) and B. longinqua Moonlight (blue). C. B. cyathophora Poepp. & Endl. (red), B. serratistipula Moonlight sp. nov. (blue) and C. vargasii Moonlight sp. nov. (green). D. B. lamolina Moonlight (red), B. lophoptera Rolfe (blue) and B. obtecticaulis Irmsch. (green). Black lines indicate country borders, grey lines indicate major administrative divisions, blue lines indicate rivers, and shading indicates elevation.