Begonia amoeboides Moonlight

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 : 66-69

9. Begonia amoeboides Moonlight

Figs 24A , 25

Phytotaxa 381 (1): 119 ( Moonlight & Reynel 2018).

– Type: PERU – Amazonas Region: Prov. Bongará • Dist. Yambrasbamba , road from Amazonas to Rioja; 5°41′22″ S, 77°49′11″ W; 2088 m a.s.l.; 31 Jan. 2016; P.W. Moonlight & A. Daza 150; holotype: MOL; isotypes: E [ E00934304 ], K, MO [ MO-3237376 ].

Begonia lophoptera Rolfe pro parte in R.Vásquez et al., Arnaldoa 12 (1–2): 112–125 ( Vásquez et al. 2005).

Begonia tiliifolia auct. non C.DC.: R.Vásquez et al., Arnaldoa 12 (1–2): 112–125 ( Vásquez et al. 2005).

Etymology

The epithet refers to the irregularly multifid stigmas of the species, which resemble the irregularly branching pseudopods of amoebae.

Selected specimens examined

PERU – San Martín Region: Prov. Rioja • Dist. Pardo Miguel, Km 382–385 Moyabamba-Bagua road ; 1850–1950 m a.s.l.; 5°41′ S, 77°39′ W; 17 Feb. 1984; D.N. Smith 6005; MO [ MO-1642478 ], US [ US00672858 ], USM. – Amazonas Region: Prov. Bongará • Dist. Yambrasbamba, Road from Amazonas to Rioja ; 5°41′16″ S, 77°47′10″ W; 2075 m a.s.l.; 3 Jul. 2018; P.W. Moonlight 1258; E, USM. – Pasco Region: Prov. Oxapampa • Dist. Huancabamba, Sector Oso Playa , camino hacia el campamento; 2478 m a.s.l.; 10°18′52″ S, 75°34′31″ W; 22 Oct. 2009; L. Valenzuela, A. Monteagudo, M. Cueva, A. Peña, J. Mateo & R. Rivera 13842; HOXA, E [ E00934198 ], MO [ MO-2991353 ], USM • Zona de amortiguamiento del Parque Nacional Yanachaga-Chemillén , Sector Oso Playa , camino a la parcela Oso Playa, 2500 m a.s.l.; 10°19′20″ S, 75°36′06″ W; 17 Jun. 2006; A. Monteagudo, L. Cárdenas, A. Peña, J.L. Mateo & R. Francis 12001; HOXA, MO [ MO-2183947 ], US [ US00951211 ], USM • Trail to summit of Cordillera Yanachaga via río San Daniel ; 2700 m a.s.l.; 10°23′ S, 75°27′ W; 13 Jul. 1984; D.N. Smith 7801; MO [ MO-1835942 ], USM • Parque Nacional Yanachaga-Chemillén , Sector San Daniel-Quebrada Colmena ; 1951 m a.s.l.; 10°27′25″ S, 75°27′20″ W; 26 Feb. 2009; R. Vásquez, L. Valenzuela & R. Rivera 35403; HOXA, E [ E00934197 ], MO [ MO-3009205 ], USM .

Description

Caulescent herb, to 150 cm high. Stem erect, occasionally branching; internodes to 15 cm long, to 8 mm thick, succulent, dark green to dark red, sparsely to densely pilose. Stipules deciduous, lanceolate, 10–40 × 5–10 mm, apex acute, translucent, pale green to dark brown, glabrous, margin entire, aciliate, the base surrounded by squamous hairs. Leaves> 5, alternate, basifixed; petiole 3.5–13.5 cm long, dark green to dark red, densely pilose; blade subsymmetric, reniform, to 11 × 16 cm, sub-succulent, apex broadly rounded, base truncate to cordate, basal lobes not overlapping, sinus to 20 mm deep, margin irregularly double-dentate, with 2–8 cusps around the lamina, ciliate, upper surface green, sparsely pilose, lower surface pale green, sparsely pilose, densely pilose on the veins, veins palmate, 8–12 veined from the base. Inflorescences 1–3, bisexual, axillary, erect, cymose, with up to 8 branches, bearing up to 16 staminate flowers and 8 pistillate flowers, protandrous; peduncle to 10 cm long, pale green to pale red, sparsely to densely pilose, bracts deciduous, lanceolate to ovate, 6–13 × 3–8 mm, translucent, white, glabrous to sparsely pilose, apex acute, margin entire, ciliate. Staminate flowers: pedicels to 15 mm long, sparsely pilose; tepals 2, spreading, ovate, 8–18 × 7–15 mm, apex acute, white or rarely pink, inner surface glabrous, outer surface pilose, margin entire to irregularly serrate, aciliate to ciliate; stamens 60–100, spreading, yellow, filaments 1–1.5 mm long, free, anthers linear, ca 2 × 0.8 mm, dehiscing via lateral slits, connectives extending to 0.4 mm, symmetrically basifixed. Pistillate flowers: pedicels to 15 mm long; bracteoles 3, positioned directly beneath the ovary, lanceolate to circular, 8–10 × 4–6 mm, apex acute, translucent, white, glabrous to short-pilose, margin entire, aciliate to ciliate; tepals 5, subequal, deciduous in fruit, projecting, lanceolate to ovate, 9–10 × 4–6 mm, apex acute to obtuse, white or rarely pink, inner surface glabrous, outer surface sparsely pilose, margin entire, aciliate; ovary body ovoid, 4–11 × 2–6 mm, pale green, sparsely pilose, unequally 3-winged, wings triangular, the largest wing notched, 4–10 × 2–7 mm, smallest 4–9 × 1.5–2.5 mm; 3-locular, placentae branches divided, bearing ovules on both surfaces; styles 3, yellow, free, 5–6 mm long, many times divided, stigmatic papillae in a spirally-twisted band. Fruiting pedicel to 25 mm long. Fruit body ovoid, to 14 × 7 mm, drying brown, wings same shape as in ovary, the largest expanding to 12 × 10 mm, the smallest to 12 × 4 mm.

Proposed conservation assessment

Assessed by Moonlight & Reynel (2018) as Data Deficient (DD).

Identification notes

Within its range, B. amoeboides can only be confused with B. lophoptera . When in flower, these two species can easily be distinguished by the number of petals on the pistillate flower (five in B. amoeboides vs two in B. lophoptera ) but they are difficult to distinguish when sterile. Begonia amoeboides can be identified by its straight, reniform leaves, which lack a distinct apex (transverse, ovate, and with a distinct apex in B. lophoptera ) and its deciduous, lanceolate stipules (vs persistent and reniform to ovate or rarely broadly lanceolate).

Distribution and ecology

Endemic to Peru and known from Amazonas, San Martín, and Pasco Regions ( Fig. 24A ). Found in upper and middle montane forest at elevations of 1850–2930 m a.s.l., where it is typically collected on wet banks. In Amazonas Region, B. amoeboides Moonlight has been observed growing adjacent to B. lamolina Moonlight and collections in Pasco Region were made at the same locality as B. lophoptera Rolfe. These three species are closely related, but no hybrids are known from either population.

Figures

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.

Fig. 25. Begonia amoeboides Moonlight. A. Habit. B. Stamen, front view. C. Staminate flower, front view. D. Pistillate flower, side view. E. Pistils, side view. Illustration by Claire Banks from P.W. Moonlight & A. Daza 150 (E).