Begonia subspinulosa 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 : 113-115

25. Begonia subspinulosa Irmsch.

Figs 35C , 39

Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie 74: 592 ( Irmscher 1949).

– Type: PERU – Cusco Region: Prov. Quispicanchis • Marcapata Valley , between Chaupichaca and Tio; [13°28′ S, 70°54′ W]; 1800–1900 m a.s.l.; 20 Feb. 1929; A. Weberbauer 7836ª; lectotype: B [ B100365202 ], designated here; isolectotypes: F [ V0042328F ], US [ US00955813 ; US00955815 ] • ibid.; A. Weberbauer 7836; syntypes: B [ B100365203 ], F [ V0042329F ]. – Cusco Region: Prov. Quispicanchis • Marcapata Valley , Ochanccaray ; [13°23′ S, 70°54′ W]; 1150 m a.s.l.; Aug. 1826; F.L. Herrera 1171; syntypes: B [ B100365201 ], US [ US00222323 ; US00967176 ] .

Brako & Zarucchi (1993: 195); León & Monsalve (2006: 169).

Begonia juntasensis auct. non Kuntze: Brako & Zarucchi, Monographs in Systematic Botany from the Missouri Botanical Garden 45: 193 ( Brako & Zarucchi 1993).

Begonia alto-peruviana A.DC. pro parte in Brako & Zarucchi, Monographs in Systematic Botany from the Missouri Botanical Garden 45: 191 ( Brako & Zarucchi 1993).

Etymology

Named for the species’ leaf margins, which are sometimes finely serrate and appear sharp.

Specimens examined

PERU – Cusco Region: Prov. Quispicanchis • río Arazá (NE of Cuzco); [13°22′ S, 70°54′ W]; 1065m a.s.l., Jan. 1943; C. Sandeman 3723; K [ K000374268 ] • Marcapata Valley, Ochanccaray ;[13°23′ S, 70°54′ W]; 1150 m a.s.l.; Aug. 1926; F.L. Herrera 1151; US [ US00222323 ] • Mandor, Marcapata ; [13°23′ S, 70°54′ W]; 1200–1300 m a.s.l.; 15 Dec. 1943; J.C. Vargas Calderón 3763; CUZ • On rocks at base of cliffs above río Arazá , about 42 kms from Quincemil on road to Urcos; [13°28′ S, 70°54′ W]; ca 1360 m a.s.l.; 12 Jun. 1960; H.E. Moore, A. Salazar C., E.E. Smith 8601; US [ US00222171 ] • Marcapata Valley , Community of Unión Arasa, Cullebrayoc trail ; 13.4947°S, 70.8731°W; 2150 m a.s.l.; 26 Apr. 2011; J.D. Wells & P. Centeno 997; CUZ. – Puno Region: Prov. Sandia • Between San Juan del Oro and San Ignacio ; [14°10′ S, 69°04′ W]; 1200 m a.s.l.; 7 Jun. 1982; D.C. Wasshausen & A. Salas 1208 a; US [ US00222019 ]. – Cultivated • Grown in Cornel University from H.E. Moore, A. Salazar C., E.E. Smith 8601 bis ; 1961; H.E. Moore, A. Salazar C., E.E. Smith 8601 bis; US [ US00222022 ] .

Description

Caulescent, herb, to at least 60 cm high. Stem erect, rarely branching; internodes to 6.5 cm long, to 6 mm thick, succulent, colour unknown, glabrous. Stipules persistent, ovate, 16–28 × 7–12 mm, apex acute, mucronate, opaque, colour unknown, glabrous, margin entire, aciliate. Leaves> 5 per stem, alternate, basifixed; petiole 1–9 cm long, colour unknown, glabrous; blade asymmetric, narrowly ovate to obovate, to 14.5 × 8.5 cm, succulent, apex short-acuminate, base transversely cordate, basal lobes not overlapping, sinus to 35 mm deep, margin serrulate to serrate, ciliate, upper surface colour unknown, glabrous, lower surface colour unknown, glabrous, veins palmate but with one primary vein, 7–9 veined from the base, with 2–3 secondary veins on the larger side, 1–3 secondary veins on the smaller side. Inflorescences 1–3 per stem, bisexual, axillary, erect, cymose, with 5–7 branches, bearing up to 32 staminate flowers and 32 pistillate flowers, protandrous; peduncle to 12.5 cm long, colour unknown, glabrous, bracts deciduous, ovate to broadly ovate, 1.8–6 × 0.8–8 mm, translucent, colour unknown, glabrous, apex rounded, margin entire to lacerate, ciliate. Staminate flowers: pedicels to 11 mm long, glabrous; tepals 2, spreading, broadly ovate, 5–14 × 4.5–10 mm, apex obtuse to rounded, pink, glabrous, margin entire, aciliate; stamens 20–35, spreading, yellow, filaments 0.5–1 mm long, free, anthers cuboid, ca 0.75 × 0.5 mm, dehiscing via lateral slits, connectives extended ca 0.1 mm, symmetrically basifixed. Pistillate flowers: pedicels to 15 mm long; bracteoles 3, positioned directly beneath the ovary, oblanceolate to obovoid, 3–8 × 1–7 mm, apex rounded to truncate, translucent, colour unknown, glabrous, margin lacerate, ciliate; tepals 3 or 5, subequal, persistent in fruit, spreading, elliptic to ovate, 3–7 × 1.5–4.5 mm, apex acute, pink, glabrous, margin entire, aciliate; ovary body ovoid, ca 4 × 2.5–4 mm, colour unknown, glabrous, unequally 3-winged, wings triangular, largest 4–7 × 3–15 mm, smallest 4–6 × 1–3 mm; 3-locular, placentae branches divided, bearing ovules on both surfaces; styles 3, yellow, free, 1.5–3.5 mm long, once-divided, stigmatic papillae in a spirally twisted band. Fruiting pedicel to 18 mm long. Fruit body ovoid, not expanding, drying brown, wings same shape as in ovary, the largest expanding to 10 × 18 mm, the smallest expanding to 9 × 8 mm.

Proposed conservation assessment

Previously assessed as Data Deficient (DD) by León & Monsalve (2006). Known from two populations, both along major roads that have been significant centres of deforestation in the past decade. The EOO of B. subspinulosa is ca 1115 km 2, so we assess B. subspinulosa this species as Endangered (EN B1ab(iii)).

Notes

The protologue of B. subspinulosa states that there are four tepals on the species’ pistillate flowers. We have dissected several flowers of this species, including from isolectotypes, and only found pistillate flowers with three or five tepals.

Typification notes

In the protologue of B. subspinulosa, Irmscher cited duplicates of A. Weberbauer 7836, 7836ª, and F.L. Herrera 1171 variously housed at B, F, and US herbaria but did not specify a holotype ( Irmscher 1949: 592). It is therefore appropriate to designate a lectotype. Most of the cited specimens are of high quality with well-pressed leaves, flowers, and fruit. We designate a sheet of A. Weberbauer 7836ª held at B (B100365202) as the lectotype of B. subspinulosa as it is particularly well mounted and with high quality dissections.

Identification notes

Begonia subspinulosa is the only member of the stenotepala group that has been collected with fewer than five tepals on the pistillate flower, though it usually has five.

Begonia subspinulosa is most similar to B. alto-peruviana and B. brevicordata (see Identification notes for B. alto-peruviana ). It could also be confused with B. stenotepala or B. deltoides sp. nov., both of which have strongly persistent stipules. It differs from both in its white to pink tepals (vs orange, red, or brown) with rounded to acute apices (vs acuminate or long-acuminate apices) and from B. deltoides sp. nov. in its transversely ovate rather than deltoid leaf laminae. The leaf margins of B. subspinulosa are serrulate while those of B. stenotepala are entire to serrulate but the teeth of B. stenotepala are barely perceptible compared to the obvious, sharp-looking teeth of B. subspinulosa .

Distribution and ecology

Endemic to Peru and known from Cusco and Puno Regions ( Fig. 35C ). Found at an elevation of 1200– 2150 m a.s.l. in lower and middle montane forest.

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. 39. Begonia subspinulosa Irmsch.A. Habit, showing pistillate flowers with five tepals. B. Staminate flower, front view. C. Staminate flower, side view. D. Pistillate flower, front-side view, sowing a pistillate flower with five tepals. Illustration by Anna Dorward from H.E. Moore, A. Salazar C., E.E. Smith 8601bis (US; A–C) and F.L. Herrera 1151 (US; D).