Begonia betancurii Jara & Moonlight, 2023

Jara-Muñoz, O. A., Moonlight, P. W. & Zabala-Rivera, J. C., 2023, A New Species of Begonia (Begoniaceae) from the Eastern Cordillera of Colombia, Phytotaxa 616 (2), pp. 169-175 : 170-173

Begonia betancurii Jara & Moonlight , sp. nov. ( Figures 1–2 )

Type:— COLOMBIA. Boyacá, Municipio de Santa María, via Santa María-Las Juntas, entrada a mano izquierda antes del tunel El Polvorín , vereda Gaceno , finca Los Alpes , cuenca de la quebrada La Esmeralda , 4°54.4’N, 73°17.7’ W, 1400–1600 m, 25 September 2009, J . Betancur, M. F. Gonzalez & estudiantes Taxonomía de Angiospermas 2009-II 14304 (holotype COL [ COL000452537 ]; isotype HUA [ HUA216209 ]) .

Diagnosis:— Begonia betancurii Jara & Moonlight can be differentiated from the other species in the section Ruizopavonia bearing staminate flowers with 4 and pistillate flowers with 3 tepals, namely: Begonia cymbalifera L.B.Sm. & B.G.Schub. , and Begonia consobrina Irmsch. , by its larger outer staminate (9.5–17.4 × 7.9–22.2 mm vs. ca. 5 × 9 mm) and pistillate (13.9–18.7 × 13.8–20.1 vs. 5–8 mm) tepals. In addition, from B. cymbalifera it can be distinguished by its palmate-pinnate venation pattern (vs. pinnate venation).

Caulescent terrestrial herb. Stem erect, to 3 m tall, frequently branching, internodes 5–8 cm long, 2.7–3.5 mm in diameter, glabrous, smooth, greenish to reddish-green, browning with age. Stipules early deciduous, lanceolate, ca. 10 × 3.5 mm, apex acute, margin entire, glabrous. Leaves alternate, basifixed; petioles joining blade at an angle of ca. 90°–120°, 12–37 mm long, glabrous; blade asymmetrical, elliptic, oblong to obovate, 9.4–18.7 × 4.2–8.7 cm, apex acuminate, base lobate on the broad side of the lamina, obtuse to rounded on the narrow side, margin serrate, upper surface green, glabrous, lower surface glabrous, green with reddish-green veins, palmate-pinnate-nerved, 11- to 14-veined on the broad side of the lamina, 9- to 11-veined on the narrow side of the lamina. Inflorescences 1–2 per branch, axillary but the youngest arising close to the apex of the stem and appearing terminal, 2–4 times dichotomous ending in cymes, with central staminate flowers developing first fallowed by lateral pistilate ones; peduncle 34–77 mm long, internodes elongate, 14–35 mm long, glabrous, pale green–flushed red. Staminate flowers: pedicels 5–15 mm long, glabrous, white to pale green; tepals 4, outer two mostly white and pinkish-white on veins and margins, ovate, 9.5–17.4 × 7.9–22.2 mm, base cordate, apex rounded, margin entire, glabrous; inner two white, narrowly oblanceolate, 3.1–4.2 × 6.5–7.2 mm, apex rounded, margin entire, glabrous; stamens ca. 55, free, filaments 1.4–2.0 mm long, anthers symmetrically basifixed, base rounded or sagittate, oblong, 2.5–4.8 mm long, dehiscing via lateral slits, connectives extended to 0.9 mm. Pistillate flowers: bracteoles 2, deciduous, reddish-green, broadly ovate, margin entire, apex denticulate, 13–18.2 × ca. 6 mm; pedicel 12–14 mm long, glabrous, pale green to reddish-green; locular region of the ovary slightly obovoid to ellipsoid, 8.1–16.2 × 3.7–10 mm, glabrous, 3-winged (rarely 4), wings white or green, unequal, largest wing asymmetric, proximal side concave, describing an arc, distal side nearly straight, forming an angle 40–60º to the perpendicular of the body apex, margin entire, 26–27 mm long, 13–16 mm wide, smaller two wings semicircular, margins entire, apex rounded, 14–16 mm tall, 7–9 mm wide; 3-locular (rarely 4-locular), placentae axilary, bifid, bearing ovules on both surfaces; tepals 3, outer two spreading to reflexed, pinkish- white, glabrous, suborbicular, 13.9–18.7 × 13.8–20.1 mm, base slightly cordate, apex rounded, margin entire; inner one white, oblanceolate or obovate, glabrous, ca. 5.5 × 1.5 mm; styles 3, multifid, divided near to the base into two or three main branches, each branch ca. 2.9 mm long, then divided into two or three twisted papillose bands (stigmatic surface), 1.8–4.1 mm long. Fruiting pedicel to 20.5–25.4 mm long. Fruit pendant, body as in the ovary, dehiscent near the back of the locules, expanding to 16.3 × 8.3 mm, light brown, glabrous, the largest wing expanding to 32 × 11 mm, similar to the wing in the ovary, green, pink or brown, longer wing expanding to 25.1 mm long, and 14.3 mm wide, shorter two wings expanding to 16 mm long, and 8 mm wide.

Phenology:— Begonia betancurii has been collected flowering and fruiting from March to October, and likely does so year-round.

Etymology:—The epithet “ betancurii ” honors the Colombian botanist Julio C. Betancur, a prolific collector of plants and for long time curator of the Colombian National Herbarium (COL), he also collected several of the specimens of this species, included the type.

Conservation Assessment:— Begonia betancurii is known from populations in Cundinamarca and Boyacá departments, which together have an Extent of Occurrence (EOO) of ca. 1050 km 2. It is known only from fragments of montane forest and is not known from any areas> 1 km from roads or urban areas. As such, we provisionally assess B. betancurii as Endangered (EN B1a,b(iii)) under IUCN Criteria ( IUCN, 2022).

Taxonomic notes:—Section Ruizopavonia was split by Moonlight et al. (2018), so its size was reduced in respect from the earlier concept of the section by Doorembos et al. (1998). After the rearrangement, 26 species were included in Ruizopavonia , while the remainder were placed in sections Cyathocnemis Klotzsch (1855: 220) De Candolle (1864: 332) , Donaldia Klotzsch (1854: 127) De Candolle (1859: 127) , Lepsia Klotzsch (1854: 123) De Candolle (1859: 139) , and Pritzelia Klotzsch (1854: 126) De Candolle (1859: 137) . However, uncertainty persisted in the placements of Bolivian members of Ruizopavonia , which were not sampled in the phylogeny. The placement of northern Andean species of section Cyathocnemis (e.g. B. magdalenae Smith & Schubert (1946: 90)) is also uncertain, and future phylogenetic evidence may result in these species being placed in sect. Ruizopavonia .

We provide a comparative table ( Table 1 ) with selected characters of B. betancurii and the most similar species in sect. Ruizopavonia , and one species in sect. Cyathocnemis ( B. magdalenae ). Our placement of B. betancurii in section Ruizopavonia is based on i) the presence of four staminate and three pistillate tepals (less than five), which is the common condition among the section, ii) oblong or elliptic anthers longer than the filaments, and iii) the raised secondary veins on the underside, which distinguish this and other sections in Neotropical clade II (NC-ii) sensu Moonlight et al. (2018) from section Lepsia . The larger size of the tepals is the most distinctive feature of the new species among species in the section Ruizopavonia and members of section Cyathocmemis from the northern Andes.

Figures

FIGURE 1. Begonia betancurii Jara & Moonlight. A. Habit; B. Staminate flower (front view); C. Pistillate flowers (front view). D. Pistillate flowers (side view), showing ovary and bract. E. Mature fruit (side view). F. Immature Fruit in cross-section showing bifid placentae. (photos A to E, by J.C. Zabala; F by M. Fernandez).

FIGURE 2.Distribution of Begonia betancurii Jara &Moonlight inColombia,showing borders of Boyacá and Cundinamarca departments, and red dots representing records of presence of the species.