Begonia solaniflora Jara, 2017

Jara-Muñoz, Orlando A., Richardson, James E. & Madriñan, Santiago, 2017, A new species of Begonia section Casparya from the Colombian Eastern Cordillera and a key to the Colombian Casparya, Phytotaxa 321 (2), pp. 208-212 : 209

Begonia solaniflora Jara sp. nov. ( Fig. 1 , 2 )

Type:― Colombia, Santander, Suaita, corregimiento San José de Suaita , entre Marbella y La Meseta. 6.254°N, 73.4231°W, 1640 m, A. Jara & J. Luna 2568, 17 Dic 2013 (Holotype: ANDES!; Isotype: COL!) .

Unlike all others species in the section Casparya (Begonia) , this species has 1) anthers connivent forming a spindle-shaped structure, 2) styles that are just once divided or not divided, and 3) leaves that are nearly symmetrical.

Plant perennial, initially erect and becoming prostrate with age, up to 70 cm high. Internodes 6.7–31.3 (65.4) mm long, up to 2.5 mm across, reddish with some parts green, glabrous, nodes thickened. Stipules early caducous, 9.7−10.6 × 2.3−3.8 mm, lanceolate, glabrous, light green to hyaline, membranous, weakly keeled, glabrous, margin entire, apex acute to obtuse and aristate, ariste ca. 0.7 mm. Petioles 3.3–10.2 × 0.8–1.1 mm; narrowly canaliculate, with some bristles near the junction with the blade ( Figure 1-C ). Leaves straight, 4.1−8.5 × 1.4−2.5 mm, elliptic to ovate, slightly asymmetric, firmly membranous; base acute; apex acute; margin serrate with a hair between each pair of teeth; venation pinnate, with 3–6 major lateral veins on each side; tertiary veins generally terminating at the margin. Inflorescence axillary, unisexual. Staminate inflorescence: reduced monochasium; peduncle 6.1−9.2 mm long, glabrous; bracteoles 5–7, the most external up to 8.1 × 5.1 mm, the others centripetal contorts gradually smaller, hyaline to greenish, from broadly ovate the outer ones to elliptic the inner, margin entire, apex obtuse, reticulations evident. Staminate flowers: 5−7, pedicels 6.4−6.8 mm long; tepals 4, glabrous, margin entire, apex obtuse, outer 2 ovate, whitish, with some reddish veins parallels, 6.4–8.1 × 3.0-3.2, inner 2, elliptic, whitish, 6.5 × 1.3 mm; stamens 5–8, disposed upon an axis of ca. 0.9 mm, anthers 2-locular, opening internally, compressed, oblong-lanceolate, ca. 3.3 × 0.4 mm, thecae in contact among them by the inner side forming a staminal spindle-shape structure, connective ca. 0.7 mm, yellow. Pistillate inflorescence: flowers solitary, peduncle 5.1–8.4, glabrous; bracts 2, broadly ovate, 6.5–7.2 × 4.5–4.9 mm, hyaline, margin entire, apex apiculate. Pistillate flowers: sessile, tepals 5, margin entire; outer 2 tepals ovate, 9.3–14.4 × 1.9–3.0 mm, whitish, with reddish variegation, apex rounded to truncate; inner 3 tepals oblong-lanceolate, 10.3 × 0.9 mm, whitish, apex obtuse: ovary trigonous, 2.9 × 6.2 mm (horns excluded), glabrous; placentation simple, ovuliferous on both sides; styles 3, simple or once divided close to the base, 7.5–8.6 mm long, yellow; stigmatic tissue covering ca. 2.5 mm, all around the style tip. Fruit obconic, 9.1–9.5 × 20.8–24.4 mm (horns included), glabrous, horns flattened, apex acute, column absent.

Additional specimens examined ― COLOMBIA: Santander, Suaita, corregimiento San José de Suaita, entre Marbella y La Meseta , 6°09’24’’N, 73°24’51’’W, ca. 1700 m. 17 Dic 2013, Jara & Luna 2563 ( ANDES), 2564 ( ANDES), 2565 ( ANDES), 2567 ( ANDES) ; 2568 ( ANDES, HUA); 2569 ( ANDES); 2570 ( ANDES, COL, HUA); vereda Campo Anibal , 6°0.8’57.2’’–6°0.9’8.0’’N–73°24’54.5’’– 73°24’33.3’’W, 1740–1810 m, 26 Mar 2004, Betancur et al. 10693 ( COL) ; Oiba, Cascadas de Chaguatá , 6°15’0’’N, 73°17’28’’W, 1460 m, 18 Dic 2013, Jara & Luna 2578 ( ANDES, COL) ; 2579 ( ANDES); 2580 ( UIS); 2581 ( COL); 2582 ( UIS); 2583 ( COL); 2584 ( UIS); 2585 ( ANDES); 2586 ( CUVC); 2587 ( JAUM); 2588 ( UDBC); 2589 ( ANDES).

Distribution and Habitat:―Moist tropical montane forest at 1460–1800 m, growing near waterfalls and streams in semi-open or shaded places. Southern region of the department of Santander ( Colombia) between the Chicamocha and Suarez Rivers.

Proposed Conservation status: ―Because the species is known from only two locations with an area of occupancy of near 8 km 2 it should be categorized as critically endangered (CR). The region where the species is growing is mostly occupied by crops and pastures (sensu IDEAM 2010). The nearest protected area is the Serranía de los Yariguies National Park ca. 20 km from the distribution locality. The park has an elevational range of between 1500 and 3200 m ( Vasquez and Serrano 2009) and only the lower part is thus suitable for this species.

Etymology:―The name refers to the general aspect of the staminate flowers that are reminiscent of Solanum flowers.

Discussion:―Due to the absence of an apical projection in the fruit (i.e. “column”), and the relationships indicated by ongoing phylogenetic work (Jara in prep.) the new species is related to species distributed in northern Colombia, Venezuela and Central America. Some species that lack the column have the hooks of the fruits flattened apically, this group was proposed as a section Aetheropteryx A. De Candolle. (1864: 271) of the formerly accepted genus Casparya including only Begonia thrispathulata (A. DC.) Warb. Since then other species with this character have been described, for example Begonia chlorolepis L.B. Sm. & B.G. Schub. (1946: 16) .

Figures

FIGURE 1. Begonia solaniflora Jara sp. nov. A) branches, B) leaf, C) detail of petiole showing hairs, D) staminate flower, E) pistillate flower and ovary, F) fruit in lateral view, G) fruit in superior view, H) transverse section of the fruit showing the unilamellar placentae.

FIGURE 2. Begonia solaniflora Jara sp. nov. (A) geographic distribution of Begonia solaniflora, (B) habitat of Begonia solaniflora, side of ravine, (C) photograph of living plant showing lateral view of the pistillate flower, indicating the bifurcate style condition. D) photograph of living plant showing the staminate flower and the large hyaline bracts.