Begonia lamolina Moonlight, 2018

Moonlight, P. W. & Reynel, C., 2018, Two new species of Begonia from Andean Peru, Phytotaxa 381 (1), pp. 116-126 : 121-122

2. Begonia lamolina Moonlight sp. nov. ( Figs. 3 , 5 ) § Cyathocnemis

Begonia lamolina is most similar to B. lophoptera Rolfe , differing in its deciduous and lanceolate stipules, acuspidate leaves, glabrous sepals on the staminate and pistillate flowers, pistillate flowers with 3 bracteoles, and its spreading styles.

Type: PERU. Department of Amazonas: Prov. Bongará: Dist. Yambrasbamba: Road from Amazonas to Rioja , 5˚41’52” S, 77˚48’35” W, alt. 2301 m, 31 January 2016, P. W. Moonlight & A. Daza 144 (holotype MOL; isotype E) .

Plant a caulescent herb, 30 cm high; stem erect, occasionally branching; internodes to 7.5 cm long, to 5 mm thick, succulent, green to red, glabrous to sparsely pilose; stipules deciduous, lanceolate, 11–15× 3–9 mm, pale green, glabrous, base surrounded by pilose hairs, cuneate, apex acute, margin entire, aciliate. Leaves alternate, spread evenly along stem, more than 5, basifixed; petiole 2.5–8 cm long, densely pilose; lamina asymmetric, transverse, ovate, 4.5–12 × 3–8.5, apex acute, base cordate, to 0.7 cm deep, lobes not overlapping, acuspidate, margin irregularly dentate, ciliate, upper surface even, green with red veins, glabrous to densely pilose, denser on major veins, lower surface even, pale green, sparsely to densely pilose; venation palmate, 6–9 veins from base. Inflorescence protanderous, axillary, erect, cymose, branching to 3 times, sparsely pilose; peduncle to 6.5 cm long, internode to 0.7 cm long; bracts deciduous, lanceolate, 4 × 2 mm, white, glabrous, apex acute, margin aciliate. Staminate flower: pedicel ca. 8 mm long; tepals 2, spreading, membranaceous, ovate, 4 × 4 mm, apex acute, base cordate, margin entire, aciliate, white, both surfaces glabrous; stamens 35–40, free, spreading, yellow, filaments 0.5–1 mm, anthers linear, 1.5–2 mm, obtuse, dehiscing through lateral slits, connective projecting to 0.2 mm. Pistillate flower: pedicel 5 mm long; bracteoles 3, ovate, 2–4 × 2–3 mm, apex rounded, glabrous, margin entire, aciliate to ciliate; tepals 2, spreading, deciduous in fruit, membranaceous, ovate, 8 × 4 mm apex obtuse, base rounded, margin entire, aciliate, white, both surfaces glabrous; ovary body ovoid, 4 × 3 mm, glabrous, green, unequally 3-winged, wings glabrous, green, the largest wing triangular, 4 × 2 mm, apex truncate and notched, ciliate, margin entire, aciliate, the smaller 2 wings oblong, 4 × 0.5 mm, margin entire, aciliate; placentae axile, bilamellate, ovuliferous all over; styles 3, deciduous in fruit, 2–2.5 mm long, bifid 0.2 mm from base, branches spreading, spirally twisted. Fruiting pedicel extending to 1 cm. Fruit pendulous, ovate, light brown, enlarging to 8 × 4 mm, the largest wing the same shape as in the ovary, enlarging to 11 × 11 mm, the smallest enlarging to a triangular wing 8 × 5 mm.

Distribution and habitat:— Peru. Known only from five collections <7 km apart on the borders of the Department of Amazonas and San Martín. The species was also observed on Trocha Kovachi [ca. 5˚40’50”S, 77˚45”15’W] in Rioja Prov. Department of San Martin in February 2016 but not collected due to permit restrictions. The species is found at low densities as a terrestrial understory herb in montane forest.

Taxonomic Comments:— When sterile, Begonia lamolina is best distinguished from B.lophoptera by its deciduous, lanceolate stipules (rather than persistent and reniform to ovate or rarely broadly lanceolate in B. lophoptera ).

Photographs of the type collection and A. Orejuela, M. Cueva & J. Castillo 2758 are available on the Begonia Resource Centre ( Hughes et al. 2015 –). The type collection was included in phylogenetic analyses by Moonlight et al. (2018).

Etymology:— The specific epithet refers to the forestry department herbarium of the Universidad Nacional Agraria la Molina , and in particular its staff Carlos Reynel and Aniceto Daza. Their invaluable work on the flora or Peru is equalled only by their work assisting visiting researchers, which have contributed to the description of numerous new taxa including both new species described in this manuscript. We treat the epithet as a non-Latin noun in apposition.

IUCN Red List Assessment:— Begonia lamolina is known from five collections made within Bosque de Protección Alto Mayo. The known extent and area of occupancy of the species are both small enough for it to qualify as Critically Endangered, but its range likely includes much of the poorly-collected, continuous band of montane forest that extends 100 km to the north and south of its known range. Accordingly, we assess B. lamolina as Data Deficient (DD) under IUCN Red List Categories and Criteria ( IUCN, 2012).

Additional specimens examined:— PERU: Department of Amazonas: Prov. Bongará: Dist. Yambrasbamba : Road from Bagua to Rioja , 5˚41’16” S, 77˚47’10” S, alt. 2075 m, 3 July 2018, P. W. Moonlight 1259 ( E, USM) ; Dist. Yambrasbamba: Road from Amazonas to Rioja , 5˚41’42” S, 77˚48’18” W, alt. 2261 m, 31 January 2016, P. W. Moonlight & A. Daza 146 ( E, MOL) ; límites con el departamento de San Martín, adelante de El Progreso, inmediaciones de la Reserva Abra Patricia, borde de carretera y entrandopor las quebradas, 5°41’58’’S, 77°48’2’’W, alt. 2231 m, 12 February 2017, A. Orejuela, M. Cueva & J. Castillo 2758 ( USM) ; Department of San Martín: Prov. Rioja: Dist. Pardo Miguel : Road from Pedro Ruiz to Rioja. Km 383, 5˚39’49” S, 77˚45’10” S, P. W. Moonlight 1268 ( E, USM) ; Dist. Pardo Miguel: Path through chacre from km 182 of road from Pedro Ruiz to Rioja, ca 500m from trail head, 5˚40’1” S, 77˚45’13” S, alt. 1801 m, 4 July 2018, P. W. Moonlight 1266 ( E, USM) .

Cultivated: Grown in the Royal Botanic Garden Edinburgh from P.W. Moonlight & A Daza 146, RBGE Living Accession 20180174, 5 March 2018, P.W. Moonlight 1142 (E).

Figures

FIGURE 3. Begonia lamolina MoonlightA. Habit; B. Branch of inflorescence; C. Staminate flower, front view; D. Pistillate flower, side view; E. Pistillate flower, front view; F.Upper leaf surface; G. Lower leaf surface; Photographs taken by Peter W. Moonlight from RBGE Living Accession 20180174, grown from P.W. Moonlight & A. Daza 144.

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