Begonia longitepala 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 : 106-108

22. Begonia longitepala Moonlight sp. nov.

urn:lsid:ipni.org:names:77323294-1

Figs 35C , 37

Diagnosis

Most similar to B. lucifuga but differing in the long-acuminate apices to both its staminate and pistillate flowers (vs rounded apices); its smaller stipules (8–12.5 × 1.5–3 mm vs 15–25 × 5–10 mm) with an acute (vs obtuse) apex; its fewer stamens (10–18 vs 25–30).

Etymology

Named for the elongate, acuminate apices of the tepals on the staminate flowers.

Type

PERU – Cusco Region: Prov. La Convención • Dist. Echarate, Kepashiato ; 12°44′02″ S, 73°22′03″ W; 1167 m a.s.l.; 19 Aug. 2006; L. Valenzuela, E. Suclli, G. Calatayud & A. Carazas 7505; holotype: MO [ MO-2038338 ] .

Specimens examined

PERU – Cusco Region: Prov. La Convención • Localidad San Antonio ; 12°25′ S, 72°11′ W; 1464 m a.s.l.; 20 Aug. 2005; G. Calatayud et al. 3295; MO [ MO-2153571 ], US [ US00932198 ] • Dist. Echarate, Santa Ana, Kepashiato , 12°44′27″ S, 73°22′14″ W; 1280 m a.s.l.; 20 Aug. 2006; L. Valenzuela, E. Suclli, G. Calatayud & A. Carazas 7523; MO [ MO-2183897 ], US [ US00951224 ], USM • Dist. Echarate, LlactaHuamán, N del río Apurimac , NE de Pueblo Libre, S de la Cordillera de Vilcabamba; 12°51′55.5″ S, 73°30′40″ W; 1650 m a.s.l.; 15 Jul. 1998; S. Baldeón M., N. Nauray, R. de la Colina & S. Udvardy 3060; US [ US00625239 ], USM .

Description

Caulescent, herb, to 60 cm high. Stem erect, rarely branching; internodes to 7.3 cm long, to 3 mm thick, succulent, colour unknown, glabrous. Stipules deciduous, lanceolate, 8–27 × 1.5–5 mm, apex acuminate, translucent, colour unknown, glabrous, margin entire, aciliate. Leaves> 5, alternate, basifixed; petiole 0.5–4.5 cm long, colour unknown, glabrous; blade asymmetric, transversely elliptic to oblanceolate, to 13 × 5.8 cm, membranaceous, apex short-acuminate to acuminate, base rounded on the widest side, cuneate on the narrow side, margin serrulate, ciliate, upper surface colour unknown, glabrous, lower surface colour unknown, glabrous, veins palmate-pinnate, 3–5 veined from the base, with 4–5 secondary veins on the larger side, 1–3 secondary veins on the smaller side. Inflorescences 1–3, bisexual, axillary, erect, cymose, with 4 branches, bearing up to 4 staminate flowers and 4 pistillate flowers, protandrous; peduncle to 9 cm long, colour unknown, glabrous, bracts late deciduous, lanceolate to oblanceolate, 2.5– 14 × 1.5–4 mm, translucent, colour unknown, glabrous, apex acute, margin lacerate, ciliate. Staminate flowers: pedicels to 9 mm long, glabrous; tepals 2, spreading, lanceolate, 5–16 × 3–8 mm, apex long-acuminate, white, pink, or orange, glabrous, margin entire, aciliate; stamens 10–18, spreading, yellow, filaments 0.5–1 mm long, free, anthers ellipsoid, 1.5–2 × 0.5 mm long, dehiscing via lateral slits, connectives extended to 0.5 mm, symmetrically basifixed. Pistillate flowers: pedicels to 8.5 mm long; bracteoles 3, positioned directly beneath the ovary, broadly ovate, 3.5–4.5 × 3–3.5 mm, apex rounded, translucent, colour unknown, glabrous, margin lacerate, ciliate; tepals 5, subequal, deciduous in fruit, spreading, lanceolate, 5–8.5 × 1.5–4 mm, apex acuminate, white, pink or orange, glabrous, margin entire, aciliate; ovary body ovoid, ca 3.5 × 2 mm, colour unknown, glabrous, unequally 3-winged, largest wing rectangular, ca 4 × 5.5 mm, smallest two triangular ca 3.5 × 2.5 mm; 3-locular, placentae unknown; styles 3, yellow, free, ca 3 mm long, once-divided, stigmatic papillae in a spirally twisted band. Fruiting pedicel to 9 mm long. Fruit body ovoid, to 7 × 3.5 mm, drying brown, wings same shape as in ovary, the largest expanding to 12 × 15 mm, the smallest to 9 × 8 mm.

Proposed conservation assessment

Known from two populations at the south of the Cordillera Vilcabamba and a third close to the border of the Santurio Nacional Megatoni. None of the known collections are in protected areas and one is immediately adjacent to a road. Satellite images taken in 2020 show extensive forest and little deforestation close to all three populations. Irrespective, we assess B. longitepala sp. nov. as Endangered (EN B1ab(iii)) on account of its low EOO (ca 660 km 2), its few populations, and the proximity of one of those collections to a road.

Notes

No specimens of B. longitepala sp. nov. are known with staminate flowers, and mature pistillate flowers, as well as fruits. We designate the sheet L. Valenzuela, E. Suclli, G. Calatayud & A. Carazas 7505 (MO [MO-2038338]) as the holotype as it is the only specimen with staminate and mature pistillate flowers.

Identification notes

Begonia longitepala sp. nov. is a rare species and difficult to identify with confidence. While it is a member of B. sect. Cyathocnemis , its slender stems, early deciduous stipules, and long-narrow leaves are not typical of the section but reminiscent of B. rossmanniae or members of B. sect. Ruizopavonia. It can be distinguished from members of both sections by its palmate-pinnate venation, which contrasts with the pinnate venation of B. sect. Ruizopavonia and pinnate venation with 3-veins from the base of B. rossmanniae .

Within B. sect. Cyathocnemis , B. longitepala sp. nov. is most similar to B. lucifuga , with which it shares its deciduous stipules and its relatively long and thin leaves. It differs in its elliptic to oblanceolate leaves (vs lanceolate); its tepals, which have a long-acuminate apex on both the staminate and pistillate flowers (vs a rounded apex in B. lucifuga ) and its stamens which do not have an extended connective. Its acuminate tepals may lead to confusion with B. stenotepala , but this species can be easily distinguished by its large (1.2–3.5 cm long), persistent stipules, which contrast with the much smaller (<1.25 cm long), deciduous stipules of B. longitepala sp. nov.

Distribution and ecology

Endemic to Peru and Cusco Region ( Fig. 35C ). Known from lower montane forest at an elevation of 1167–1650 m a.s.l.

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.

Fig. 37. Begonia longitepala Moonlight sp. nov. A. Habit. B. Stipule. C. Staminate flower, front view. D. Staminate flower, side view. E. Pistillate flower, side view. F. Fruit, side view. Illustration by Anna Dorward from L. Valenzuela, E. Suclli, G. Calatayud & A. Carazas 7523 (US).