Begonia amoeboides Moonlight, 2018

Moonlight, P. W. & Reynel, C., 2018, Two new species of Begonia from Andean Peru, Phytotaxa 381 (1), pp. 116-126 : 119-121

1. Begonia amoeboides Moonlight sp. nov. ( Figs. 1–2 , 5 ) § Cyathocnemis

Begonia amoeboides is most similar to B. lophoptera Rolfe , but differs in its deciduous and lanceolate stipules (persistent and ovate in B. lophoptera ), five tepals on the female flower (two in B. lophoptera ), multifid styles (bifid in B. lophoptera ), and its stamen number (60–100 in B. amoeboides , 25–35 in B. lophoptera ).

Type: PERU. Amazonas Department. Prov. Bongará: Dist. Yambrasbamba: Road from Amazonas to Rioja , 5˚41’22” S, 77˚47’11” W, alt. 2088 m, 31 January 2016, P. W. Moonlight & A. Daza 150 (holotype MOL; isotype E, K, MO, USM) .

Plant a caulescent herb, 40–150 cm high; stem erect, occasionally branching; internodes to 15 cm long, to 8 mm thick, ridged, succulent, dark green to dark red, sparsely to densely pilose; stipules, deciduous lanceolate, 10–40 × 5–10 mm, dark brown to pale green, glabrous, base surrounded by squamose hairs, attenuate, apex acute, margin entire, aciliate. Leaves alternate, spread evenly along stem, more than 5, basifixed; petiole 3.5–13.5 cm long, densely pilose; lamina subsymmetric, straight, reniform, 5.5–11 × 7–16 cm, apex broadly rounded, base truncate to cordate, to 2 cm deep, lobes not overlapping, with 2–8 cusps around the lamina, margin irregularly double-dentate, ciliate, upper surface even, green, sparsely pilose, lower surface even, pale green, sparsely pilose, densely tomentose on veins; venation palmate, 8–12 veins from base. Inflorescence protanderous, axillary, erect, cymose, branching to 3 times, sparsely to densely pilose; peduncle to 10 cm long, internodes to 3 cm long; bracts deciduous, lanceolate to ovate, 6–13 × 3–8 mm, translucent to white, glabrous to sparsely pilose, apex acute, margin ciliate. Staminate flowers: pedicel 8–15 mm; tepals 2, spreading, membranaceous, ovate, 8–18 × 7–15 mm, apex acute, base cordate, margin entire to irregularly serrate, aciliate to ciliate, white or rarely pink, upper surface glabrous, lower surface pilose; stamens 60–100, free, spreading, yellow, filaments 1–1.5 mm, anthers linear, 2– 0.8 mm, obtuse, dehiscing through lateral slits, connective projecting to 0.4 mm. Pistillate flowers: pedicels 10–15 mm. bracteoles 3, lanceolate to rounded, 8–10 × 4–6 mm, apex acute, glabrous to short pilose, margin entire, aciliate to ciliate; tepals 5, projecting forwards, deciduous in fruit, membranaceous, lanceolate to ovate, 9–10 × 4–6 mm, apex acute to obtuse, base cuneate, margin entire, aciliate, white or rarely pink, upper surface glabrous, lower surface sparsely pilose; ovary body ovoid, 4–11 × 2–6 mm, sparsely pilose, pale green, unequally 3-winged, wings sparsely pilose, pale green, the largest wing triangular, 4–10 × 2–7 mm, apex truncate and notched, ciliate, margin entire, aciliate, the smaller 2 wings oblong to triangular, 4–9 × 1.5–2.6, margin entire, aciliate; placentae axile, bilamellate, ovuliferous all over; styles 3, deciduous in fruit, 5–6 mm long, irregularly multifid 1 mm from base, branches spreading, spirally twisted. Fruiting pedicel extending to 2.5 cm. Fruit pendulous, ovate, light brown, enlarging to 14× 7 mm, the largest wing the same shape as in the ovary, enlarging to 14 × 11 mm, the smallest enlarging to a triangular wing 14 × 9 mm.

Distribution and habitat:— Begonia amoeboides has been collected in the Department of Amazonas, San Martín, and Pasco on the western slope of the Andes of northern Peru. It is typically found on moist banks in montane forest.

Taxonomic Comments:— All known specimens of Begonia amoeboides were previously determined as B. lophoptera . When flowering, it is trivial to tell these two species apart by the number of female tepals, however, determining sterile specimens can be problematic. B. amoeboides can be distinguished vegetatively 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 (versus persistent and reniform to ovate or rarely broadly lanceolate).

Photographs of the type collection are available from the Begonia Resource Centre ( Hughes et al. 2015 –Present). The type collection was included in phylogenetic analyses by Moonlight et al. (2018).

Etymology:— The epithet “amoeboides ” refers to the irregularly multifid stigmas of the species, which resemble the irregularly branching pseudopods of amoeba.

IUCN Redlist Assessment:— Begonia amoeboides is known from two small populations in the protected areas of Bosque de Protección Alto Mayo and Parque Nacional Yanachaga-Chemillén. The species is locally common in its known range and much of the 550 km between these two populations are poorly explored. Accordingly, we treat B. amoeboides as Data Deficient (DD) under IUCN Red List Categories and Criteria ( IUCN, 2012).

Additional specimens examined:— PERU. Department of San Martín : Prov. Rioja: Dist. Pardo Miguel: Km 382–385 Moyabamba-Bagua road, alt 1850–1950 m, 5˚41’ S, 77˚39’ W, 17 February 1984, D. N. Smith 6005 ( MO, USM) ;

Department of Amazonas. Prov. Bongará: Dist. Yambrasbamba: Road from Amazonas to Rioja, 5˚41’16” S, 77˚47’10” W, alt. 2075 m, 3 July 2018, P. W. Moonlight 1258 ( E, USM). Department of Pasco: Prov. Oxapampa: Dist. Huancabamba: Sector Oso Playa, camino hacia el campamento, alt. 2478 m, 10˚18’52” S, 75˚34’31” W, 22 October 2009, L. Valenzuela, A. Monteagudo, M. Cueva, A. Peña, J. Mateo & R. Rivera 13842 ( HOXA, E, MO) ; Zona de amortiguamiento del Parque Nacional Yanachaga-Chemillén, Sector Oso Playa, camino a la parcela Oso Playa, 2500 m, 10˚19’20” S, 75˚36’06” W, 17 June 2006, A. Monteagudo, L. Cardenas, A. Peña, J. L. Mateo & R. Francis 12001 ( HOXA, MO, USM) ; Oso Playa, alt. 2200 m, 10˚19’21” S, 75˚34’11” W, 26 June 2004, R. Rojas & J. Perea 3101 ( HOXA, MO) ; ibid, 31 May 2004, R. Rojas, M. Huaman, A. Peña & J. Mateo 2443 ( HOXA, MO) ; Abra Yanachaga, Parque Nacional Yanachaga-Chemillén, alt. 2930 m, 10˚22’46.3” S, 75˚27’42.9” W, 3 August 2005, E. Ortiz V. & R. Francis J. 734 ( HOXA, MO) ; Trail to summit of Cordillera Yanachaga via río San Daniel , alt. 2700 m, 10˚23’ S, 75˚27’ W, 13 July 1984, D. N. Smith 7801 ( MO, USM) ; Parque Nacional Yanachaga-Chemillén, Grapanazú-Sector San Daniel, Naciente de la Quebrada Colmena, alt. 2200–2500 m, 10˚26’35” S, 75˚26’16” W, September 2005, S. Vilca C., E. Ortiz V. & J. Mateo M 229 ( HOXA, MO, USM) ; Localidad Grapanazú, sector San Daniel, zona de amortiguamiento del Parque Nacional Yanachaga-Chemillén, 2236 m, 10˚26’36” S, 75˚26’21” W, 10 July 2004, J. Perea, R. Francis, H. Cristóbal & E. Camavilca 1472 ( HOXA, MO) ; Parque Nacional Yanachaga-Chemillén, Sector San Daniel-Quebrada Colmena, 1951 m, 10˚27’25” S, 75˚27’20” W, 26 ii 2009, R. Vásquez, L. Valenzuela & R. Rivera 35403 ( HOXA, E, MO, USM) .

Figures

FIGURE 1. Begonia amoeboides Moonlight A. Habit; B. Branch of inflorescence; C. Developing fruit flower, side view; D. Staminate flower, front view; E. Upper leaf surface; F. Lower leaf surface; Photographs taken by Peter W. Moonlight from P.W. Moonlight & A. Daza 150.

FIGURE 2. Begonia amoeboides Moonlight A. Habit, showing young inflorescence and young infructescence; B. Male flower, front view; C. Stamen, front view; D. Female flower, side view; E. Stigmas, side view. Illustration by Claire Banks from P.W. Moonlight & A. Daza 150 (A, D, E) and Valenzuela et al. 13842 (B, C).

FIGURE 5. Distributions of Begonia amoeboides Moonlight (blue), Begonia lamolina Moonlight (red), and Begonia lophoptera Rolfe (green). Shading indicates altitude.