Begonia castrosouzae L. Kollmann 2022, sp. nov.
Creators: name: Kollmann, Ludovic Jean Charles
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Cucurbitales
Begoniaceae
Begonia
Begonia castrosouzae

description: Begonia castrosouzae L.Kollmann, sp. nov. (Figs 1–4)
Diagnosis:— Begonia castrosouzae is closely related to Begonia magdalenensis Brade (1945: 19) but can be distinguished by its leaf apex that is obtuse, acute to short apiculate (vs long apiculate), persistent stipules (vs caducous), bracts persistent (vs caducous), sepals of male and female flowers and fruits hairy (vs glabrous).
Type:— BRAZIL. São Paulo: Mun. Sete Barras, Parque Estadual Carlos Botelho, 300m elevation, 09 March 2019, L. Kollmann, H. Lorenzi & V. C. Souza 13566 (holotype MBML!, isotype ESA!, RB!).
Description: — Perennial, erect herbs, turning decumbent when old, 16–35 cm tall, lanulose, ferruginous simple trichomes. Stems with 1–2.5 cm long internodes, brown, lanulose, glabrescent. Stipules 1–1.5 × 0.3–0.8 cm, brown, triangular, apex acute, abaxial face carinate, margin entire, persistent, lanulose. Petioles 5.5–13.5 cm long, brown, lanulose. Leaf blade 7.7–16 × 4.5–9 cm, asymmetrical, basifixed, oval to obovate, dark green, veins light green when young in adaxial surface, glabrous, red to wine-coloured in abaxial surface, sparsely pilose, apex acute to short apiculate, base cordate, lobes overlapping the petiole, margin irregularly crenate, venation actinodromous, 5–8 veins at base, pilose. Inflorescences 18–24 cm long, 2–4-dichasial cymes, pilose; bracts 0.5–1.6 × 0.2–0.45 cm, elliptical to oblanceolate, white to pinkish, persistent to tardily deciduous, pilose on adaxial face, apex acute. Male flowers: pedicels 0.5–1.4 mm long, white to pinkish; sepals 2, 1.5–2.1 × 0.6–0.8 cm, white, lanceolate to elliptical, pilose on adaxial surface, apex acute, margins entire; petals 2, 1–1.2 × 0.5–0.7 cm, white, oblanceolate to elliptical, glabrous, apex obtuse to acute, margins entire; stamens ca. 14-16, yellow, filaments equal, ca. 1 mm long, anthers ca. 2 mm long, rimose, oblong, connective projecting, apex rounded. Female flowers: pedicels 0.5–0.9 cm long, white to pinkish, pilose; prophylls 1, one the apex of the pedicel, 2.5–4 × 0.5–1 mm, elliptical, persistent, pilose, apex acute; sepals 2, 0.7–1.2 × 0.5–1.1 cm, white, elliptical to obovate, pilose on adaxial surface, apex obtuse to acute; petals 3, 0.5–1.2 × 0.3–1 cm, white, elliptical to oblanceolate to obovate, apex obtuse to rounded; ovary 3-locular, placentation axile, one placentae per locule; styles 3, ca. 4 mm long, yellow, united at base, each bifurcate, with band of stigmatic papillae. Capsule 0.9–12 × 2.5–3 mm, basally dehiscent, pilose, Pedicels of fruit 0.9–1.35 cm long, pilose, wings 3, unequal, largest one 1.2–1.4 × 0.8–1.1 cm, straight to ascendent, apex acute, two smallest 1–1.4 × 0.7–1 cm, straight to ascendent, apex acute. Seeds ca. 0.3 mm long, oblong, apex rounded.
Additional specimens examined (paratypes):— BRAZIL, São Paulo, Sete Barras, Parque Estadual Carlos Botelho, mata atlântica, em área pedregosa e montanhosa, 24°19’1.6’’ S, 47°55’1.8W, 300m, 25 January 2002 C. D. Feliciano s.n. (ESA111739!); parcela A15 do projeto BIOTA, 12 January 2004, C. D. Feliciano s.n. (ESA111769!, MBML!); parcela D10 do projeto BIOTA, 14 January 2004, C. D. Feliciano s.n. (ESA111776!); Floresta Ombrófila Densa, área do projeto parcelas permanentes, 300m. a.s.l.; Souza, 18 February 2003, V. C. et al. 29009 (ESA 83731!, MBML!).
Distribution, habitat and phenology:— Begonia castrosouzae occurs at 300 m elevation, in soil or humus in the forest floor. The predominant vegetation is Ombrophilous Dense Forest (Atlantic Forest). Flowering from January to March and fruting from May to November.
Conservation status:— B. castrosouzae is endemic to the Carlos Botelho State Park, with AOO of 4 km 2 and a not defined EOO. Due to the species apparent rarity and restricted endemic distribution, eventhough the population is inside a fully protected Conservation Unit. I suggest that this species ought to be included in the Vulnerable category [VU: D2] (IUCN, 2019).
Etymology:—The name of the new species is a homage to Vinicius Castro Souza, who has greatly contributed to the knowledge of the Brazilian Flora and helped to find the new species in the field.
Notes:—In the PECB approximately 11 new species of different plants family are described from this area, demonstrating the high level of diversity of the region (Clarck, 2004; Gentry, 1992; Kawas, & Host 2002; Moraes, 2007; Wanderley & Proença 2006). Especifically for Begoniaceae, Begonia capanemae Brade (1954: 73), B. cucullata Willd. (1805: 414), B. fischeri Schrank (1820: pl. 59), B. fruticosa (Klotzsch) A.DC. (1861: 377), B. herbacea Vell. (1827: pl. 53), B. inculta Irmsch. (1953: 48), B. radicans Vell. (1827: pl. 39) and B. valdensium A.DC. (1859: 138) are recorded for this region.
According to the sectional classification of Doorenbos et al. (1998) and Moonlight et al (2018), Begonia castrosouzae belongs to the section Pritzelia alongside approximately 150 species from South America. This section shares entire placentae and the presence of cystoliths in the leaf cells (Doorenbos et al. 1998).
description: Published as part of Kollmann, Ludovic Jean Charles, 2022, NOVELTIES IN BRAZILIAN BEGONIACEAE V: a new species from southern São Paulo state, pp. 240-246 in Phytotaxa 541 (3) on pages 241-245, DOI: 10.11646/phytotaxa.541.3.3, http://zenodo.org/record/6392608