Saturday, March 14, 2020

[Botany • 2020] Begonia oleosa (Begoniaceae) • the First Species with Glandular Hairs in the Section Casparya


Begonia oleosa Jara
in Jara-Muñoz, 2020.

Abstract
 A new species of Begonia section Casparya from Colombia and Venezuela is described and illustrated. Begonia oleosa is closely related to Begonia toledana var. erubescens but differs mainly by its glandular trichomes. 

Keywords: Cucurbitales, northern Andes, taxonomy.

FIG. 2. Begonia oleosa.
A. Habitat. B. Branch with fruits. C. Pistillate flowers. D. Staminate flower.
 (Images from the type collection.)

Begonia oleosa Jara, sp. nov.

 Diagnosis: This species can be distinguished from Begonia toledana var. erubescens L.B. Sm. & B.G. Schub. by the presence of glandular hairs, larger leaves (7.9−14.9 × 2.2−5.0 vs. 2.5−6.9 × 0.8−1.9 cm), and entire placentae (vs. bilamellated).

Distribution and habitat.— This species has been found in the north of the Colombian Eastern Cordillera and the Venezuelan Cordillera de Mérida (States of Mérida and Táchira), at 2400–2900 m. It has been observed growing in semi-open and shaded areas on the side of routes and streams, sometimes on saturated soils, but also in dry and clayey soils, where the plants are smaller. The forests where Begonia oleosa grows are dominated by the genera MiconiaPalicoureaClusia, and Schefflera, as well as the families Lauraceae, Ericaceae, Solanaceae and Asteraceae (e.g., Alvear et al., 2010; Galindo et al., 2003; Fig. 2A).

Etymology.—The name is derived from the Latin “oleum”, referring to oil, in this case alluding to the oily nature of the surfaces of the leaves and stems resulting from secretions of the glandular hairs.


Orlando Adolfo Jara-Muñoz. 2020. Begonia oleosa (Begoniaceae), the First Species with Glandular Hairs in the Section CasparyaBrittonia. DOI: 10.1007/s12228-020-09605-0

Resumen: Se describe e ilustra una nueva especie de Begonia, secciÆn Casparya de Colombia y Venezuela. Begonia oleosa estÄ cercanamente emparentada con Begonia toledana var. erubescens, pero difiere de esta principalmente por sus tricomas glandulares.