Begonia lucifuga Irmsch.

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 : 108-110

23. Begonia lucifuga Irmsch.

Fig. 35B

Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie 74: 608 ( Irmscher 1949) .

– Type: PERU – Junín Region • Huacapistana ; [11°14′ S, 75°31′ W]; 1800 m a.s.l.; 6 Jun. 1929; E.P. Killip & A.C. Smith 27300; holotype: US [ US00955825 ]; isotype: NY [ NY01085496 ] .

Brako & Zarucchi (1993: 193); Vásquez et al. (2005: 112–125); León & Monsalve (2006: 167).

Etymology

The epithet derives from the Latin ‘ lux ’ and ‘ fugure ’ meaning ‘light’ and ‘to escape’. This refers to the species’ preferred habit, which is deep shade.

Specimens examined

PERU – Pasco Region: Prov. Oxapampa • Dist. Palcazú, Bosque de protección San Matias-San Carlos. Bosque Secundario Sector Unión-Shimakii ; 10°45′04″ S, 74°55′47″ W; 1350–1420 m a.s.l.; 3 Jun. 2003; A. Monteagudo & G. Ortiz 5685; HOXA, MO [ MO-842669 ] . – Junín Region: Prov. Chanchamayo • Santa Ana, fondo Romero, Pampatigre , above Santa Ana (SE of La Merced); 11°S, 75°10′ W; 1500–1700 m a.s.l.; 7 Mar. 1985; B.A. Stein & C. Todzia 2338; MO [ MO-1835893 ] • 1 km along path N along tributary of río Tarma from E side of Puente de Azúcar; 11°10′21″ S, 75°27′13″ W; 1523 m a.s.l.; 23 Jun. 2014; P.W. Moonlight & A. Daza 46; MOL .

Description

Caulescent herb, to 40 cm high. Stem erect, rarely branching; internodes to 2.5 cm long, to 6 mm thick, succulent, red, glabrous. Stipules deciduous, ovate, 15–25 × 5–10 mm, apex obtuse, translucent, red, glabrous, margin entire, aciliate. Leaves> 3, alternate, basifixed; petiole 15–30 cm long, red, glabrous; blade asymmetric, lanceolate, to 12 × 5 cm, succulent, apex acuminate, base obliquely truncate to obliquely cordate, basal lobes overlapping on the young leaves, sinus to 5 mm deep, margin serrulate to serrate, ciliate, upper surface dark green, glabrous, lower surface red, glabrous, veins palmate-pinnate, 6–8 veined from the base, with 5–7 secondary veins on the larger side, 2–5 secondary veins on the smaller side. Inflorescences 1–3, bisexual, axillary, erect, cymose, with 3–4 branches, bearing up to 8 staminate flowers and 8 pistillate flowers, protandrous; peduncle to 7 cm long, colour unknown, glabrous, bracts deciduous, obovate, ca 2–3 × 1 mm, translucent, colour unknown, glabrous, apex truncate, margin entire, sparsely ciliate. Staminate flowers: pedicels to 24 mm long, glabrous; tepals 2, spreading, broadly ovate, 9–15 × 8–13 mm, apex rounded, pale pink, glabrous, margin entire, aciliate; stamens 25–30, spreading, presumed yellow, filaments 1–2 mm long, free, anthers ellipsoid, 1–2 × 0.5 mm long, dehiscing via lateral slits, connectives extended to 0.2 mm, symmetrically basifixed. Pistillate flowers: pedicels to 15 mm long; bracteoles present, number unknown, positioned directly beneath the ovary, elliptic, ca 1.5 × 1 mm, apex obtuse, translucent, colour unknown, glabrous, margin serrulate, ciliate; tepals 5, subequal, persistence in fruit unknown, projecting, ovate, 3–5 × 2–3 mm, apex obtuse to rounded, pink, glabrous, margin entire, aciliate; ovary body ovoid, ca 2.5–4 × 1–2 mm, colour unknown, glabrous, unequally 3-winged, wings triangular, largest 3–5 × 2–3 mm, smallest 3–4 × 1–1.5 mm; 3-locular, placentae branches divided, bearing ovules on both surfaces; styles 3, colour unknown, free, ca 1.5 mm long, once-divided, stigmatic papillae in a spirally twisted band. Fruiting pedicel unknown. Fruit unknown.

Proposed conservation assessment

Previously assessed as Data Deficient (DD) by León & Monsalve (2006). Known from four collections across four populations with a combined EOO of 214 km 2. Despite extensive fieldwork in the species’ range, we have only been able to locate a single individual (P.W. Moonlight & A. Daza 36), likely because the range of B. lucifuga is centred on the valley of the río Chanchamayo. The Peruvian “Carretera Central” (National Route 22) descends from the Andes to the Amazon along this valley and is the only major road across the Andes for ca 200 km in either direction. The Carretera Central has been a major route for more than 150 years and most of the Lower Montane Forest within the valley has been cleared for agriculture. We are also confident that B. lucifuga does not grow in large numbers north of its known range in Pasco Region because this part of Peru has for the past 20 years been one of the most intensively collected areas of tropical forest in the world. Considering its rarity, small range, and the habitat destruction across that range, we assess B. lucifuga as Endangered (EN B1ab(iii)+B2ab(iii)).

Identification notes

Within the stenotepala group, B. lucifuga is most similar to B. brevicordata and B. subspinulosa . These three species have white or pink tepals and the tepals on their staminate flowers have a rounded apex while the other species in the complex have bright red or orange tepals with an acute to narrowly acute apex. Begonia lucifuga differs from these two species in its leaf margins, which are serrulate as opposed to serrate or dentate. Its leaves are also lanceolate in outline and have an acuminate apex, whereas those of B. subspinulosa are ovate and those of B. brevicordata are broadly ovate in outline and both species have short acuminate leaf apexes.

When sterile, B. lucifuga is most likely to be confused with B. stenotepala or B. lucifuga . It can be distinguished from B. stenotepala by its stipules, which are deciduous whereas those of B. stenotepala are persistent. Begonia longitepala sp. nov. also has deciduous stipules but differs in its elliptic to oblanceolate leaf laminae.

Distribution and ecology

Endemic to Peru and known from Pasco and Junín Regions ( Fig. 35B ). Found in lower montane forest at an elevation of 1350–1800 m a.s.l. Begonia lucifuga is found in deep shade and humid areas, including in the shade of forests within gorges.

Figures

Fig. 35. Distribution of the stenotepala group of Begonia sect. Cyathocnemis (Klotzsch) A.DC. in Peru and surrounding countries. A. B. alto-peruviana A.DC. (red). B. B. brevicordata L.B.Sm. & B.G.Schub. (red), B. deltoidesMoonlight sp. nov. (blue), and B. lucifuga Irmsch (green). C. B. longitepalaMoonlight sp. nov. (red) and B. subspinulosa Irmsch. (blue). D. B. stenotepala L.B.Sm. & B.G.Schub. (red). Black lines indicate country borders, grey lines indicate major administrative divisions, blue lines indicate rivers, and shading indicates elevation.