Begonia perijaensis Jara, 2021

Jara-Muñoz, Orlando Adolfo, Richardson, James E. & Zabala-Rivera, Juan Carlos, 2021, Five new species and three new varieties of Begonia section Casparya endemic to Colombia, Phytotaxa 525 (4), pp. 258-280 : 270-273

Begonia perijaensis Jara , sp. nov. Figs. 6 & 10

Type:— COLOMBIA. Guajira: municipio Urumita, zona de Cerro Pintado, 10.433ºN, 72.908ºW, 3135 m. 13 November 2015, A . Jara 2871 (holotype JBB!, isotype ANDES!) .

Diagnosis:—This species can be distinguished from Begonia trianae due to the smaller size of the plants (to 40 cm tall vs.> 40 cm tall in B. ursina ) and its succulent stems (vs. fibrous). The staminate flowers in B. perijaense have shorter pedicels than B. trianae (to 9 mm vs. 40-60 mm long) and the perianth has 6 tepals (vs. 5). It can be distinguished from Begonia ursina by the smaller plant size (to 40 cm tall vs.> 40 cm tall), succulent stems (vs. fibrous), its leaf laminae oblique to the petiole (vs. straight), and its longer leaf laminae (4.9−9.5 vs. 11–14.5 cm). From Begonia chlorolepis it can be distinguished by the fruit having the apex of the horns vertically flattened (i.e., compressed) vs. horizontally flattened (i.e. depressed).

Description:—Herb, to 40 cm high. Stem erect, few branched, internodes to 6.5 cm long, succulent, grayishgreen, densely pubescent. Stipules persistent, densely pubescent, green, reniform, ca. 8 × 15 mm, apex rounded, margin denticulate. Petiole pale green, pubescent, 3–8.5 cm long, lamina of the leaf strongly oblique to the petiole, coriaceous, asymmetric, ovate, 11–14.5 × 4.6–7.7 cm, base lobulate on one side, rounded on the other side, margin crenate-serrate, apex short acuminate, lower surface densely pubescent, pale green to whitish-green with purple hairs, upper surface green, densely pubescent, veins palmate-pinnate, with 8–9 secondary on the larger side, 5–6 secondary veins on the smaller side. Inflorescence unisexual in dioecious plants; staminate inflorescence axillary, erect, umbel-like contracted cincinnus, bearing up to 5 flowers; peduncle to 6 cm long, whitish-green to pale green, densely pubescent, bracts deciduous, pale green, pubescent, ovate, to 10 mm long, margin entire, apex obtuse. staminate flowers: pedicels to 3.8 mm long, pubescent; tepals 4, spreading, outer 2 covered with white hairs outside and glabrous inside, widely elliptic, 6.7–7 × 5.5–7.6 mm, margin entire and ciliate toward the apex, apex rounded or truncate, inner 2 glabrous and white on both sides, elliptic, 4.9–6 × 2–2.3 mm, margin entire, apex rounded or truncate; stamens up to 35, spreading, yellow, filaments ca. 1 mm long, free, anthers linear-obovoid, ca. 2.7 × 0.9 mm, dehiscence slightly introrse, connectives shortly projecting, truncate. Pistillate inflorescence axillary and solitary flowers. Pistillate flowers: pedicels white pubescent, to 9 mm long; bracteoles, densely pubescent, small, ca. 3 × 2 mm; ovary body green and densely white pubescent, turbinate, 13 × 19 mm, sub-equally 3-winged, wings ovate, ca. 9 × 8 mm; placenta bifid, bearing ovules on both surfaces; perianth in two series with 3 tepals in each one, the outer tepals pale green and reddish-green pubescent outside, white inside, spreading, ovate, ca. 17 × 11 mm, margin entire and ciliate toward the apex, apex acute, the inner tepals sparsely pubescent outside to glabrous, elliptic, ca. 13 × 6.5 mm, margin entire, apex acute; styles multifid, 4–5 mm long, stigmatic papillae restricted twisted apex of the styles. Fruiting pedicel to 12 mm long. Fruit a capsule, densely pubescent, body and wings like the ovary, to 14 × 34 mm, wings to 13.5 mm long, apex obtuse, apical column absent.

Etymology:—This species is named for the Serranía of Perijá, at the northern border between Colombia and Venezuela, where the species is endemic.

Distribution and habitat:—Only known from the type specimen in the peak Cerro Pintado (also spelled “Cerro del Pintao” and known as “Cerro Viruela” in Venezuela), which is one of the highest mountains of the Perijá serrania, reaching 3300 m (Rangel 2009). Vegetation there is sub-paramo dominated by Calamagrostis sp. , and accompanied by several species of Asteraceae , as well as Hesperomeles ferruginea , Otholobium sp. (Fabaceae) , Geranium sp. (Geraniaceae) and Monnina sp. (Polygalaceae) (pers. obs.). The peak is formed of upper Cretaceous limestone from the Cogollo formation, and has geomorphological evidence of glaciations ( Lazala 2007, Rodriguez & Galán 2008).

Conservation status:― We included this species in the category of Critically Endangered (CR B2a,b(iii)) according to the IUCN criteria B2, because its AOO is less than 10 km 2, being only about 1 km 2, based on the only known population, and the EOO is less than 100 km 2. It is found at only one location, and there is evidence of destruction of the vegetation during the last 30 years, even though this zone is included in a forest reserve ( Vásquez & Serrano 2009).

Notes:— Begonia perijaensis grows very close to Begonia ursina , which is the most common species of the section in the Serranía de Perijá, ranging between 2300 and 3100 m, while B. perijaensis is restricted to the higher part of the Cerro Pintado peak.

Figures

FIGURE 6. Begonia perijaensis. A) Branch, B) Branch detail with pistillate flowers, C) Staminate flower seen from above, D) Pistillate flower seen from above, E) Fruit. Based on live plant in the Bogota Botanic Garden, and from A. Jara 2871, by O. Bernal.

FIGURE 10. Distribution of Begonia silverstonei var. brevipetiolata, Begonia perijaensis, Begonia vinagrera var. vinagrera, and Begonia vinagrera var. pomecensis.