Begonia langenbergiana L. Kollmann, 2018

Kollmann, Ludovic Jean Charles, 2018, Begonia langenbergiana (Begoniaceae) a new species from the south of São Paulo State, Brazil, Phytotaxa 381 (1), pp. 80-85 : 81-84

Begonia langenbergiana L. Kollmann , sp. nov. ( Figs. 1 ; 2 , 3 ).

Begonia langenbergiana is closely related to B. itaguassuensis in its rhizomatous habit, its indumentum of simple trichomes, its reniform, apiculate leaves, its dichotomous inflorescence with persistent bracts and 2 prophylles on pistillate flowers, but can be distinguished by its bullate leaves with adaxially introse and abaxially prominent veins. Furthremore, its first flowers are erect and open when the inflorescence is small and still growing, until his maturity; and the first ramifications of the inflorescences are erect when the inflorescence is growing and until his maturity, and its stigma is without a stigmatic band.

TYPE: BRAZIL. São Paulo: Iporanga, Vale do Ribeira, 18.Jun.1995 (fr.), A. T. Dias et al. s.n.. (holoype FUEL 17820!, isotype MBML 50649!)

Herbaceous, rhizomatous, 11–32 cm tall, simple trichomes. Stems 0.5–1 cm diam. rooting at the nodes, internodes 0.5–1 cm long, green to reddish, lenticellate. Stipules persistent, 1.5–2.8 × 0.8–2 cm, papiraceous when dry, greenish to reddish, translucent, asymmetrical, triangulate, lenticellate, apex mucronate, margins entire, abaxial face carinate. Petioles 4–22.5 cm long, green to reddish, lenticellate, villose. Lamina 6–11 × 8–15 cm, asymmetrical, reniform, lightly bullate, hispid, apex acuminate, base cordate, overlapping, margins reddish, denticulate to dentate, ciliate, venation actinodromous, 7–8 veined at base, veins adaxially introse, abaxially prominent, hispid. Inflorescences with 2–4 dichotomous cymes, 10–32 cm long, reddish, lenticellate; bracts persistent, 1–2 × 0.5–1 mm, reddish, triangular, apex acute, glabrous. Staminate flowers: pedicels 1–3.5 cm long, white, glabrous; 2-sepals, 9–13 × 4–9.5 mm, white to pinkish, oblong to obovate, apex rounded to obtuse, margins entire; 2-petals, 6.2–10 × 1.5–5 mm, white to pinkish, elliptical to obovate, apex obtuse, margins entire; stamens 11–13, yellow, filaments 0.5–1 mm long, anthers 3.4–3.5 mm long, rimose, connective slightly projecting, apex obtuse. Pistillate flowers: pedicels 0.8–1 cm long, white, glabrous; prophylls 2, 0.8–1.5 × 0.4–0.8 mm, pinkish, triangulate, apex acute; 2-sepals, 3.5–9 × 2.2–3 mm, pinkish, ovate to triangulate, apex acute; 3-petals, 8.5–12 × 4–6 mm, pinkish, elliptical to oblanceolate, sometime falcate, apex obtuse to acute; ovary 3-locular, axile placentation, one placentae per locule, ovules on both sides of placentae; 3-styles, persistent on dry fruit, ca. 3.5 × 2 mm, yellow, united at base, each bifurcate, not spiral, stigmatic papillae covering all the style. Capsules 7–8 × 5–7 mm, basally dehiscent, 3-wings, subequal, white to pinkish, larger one 0.8–1.5 × 0.7–1.3 cm, smaller two 0.7–1.4 × 0.5–0.85 cm. Seeds ca. 0.35 × 0.25 mm, cylindrical, apex rounded.

PARATYPES: BRAZIL. São Paulo: Iporanga, Morro Preto, 7 March 1986 (fl.), F. Chagas e Silva, M. C. Dias & L. H. S Soares 1050 ( FUEL 2026!). BRAZIL. Espirito Santo: Santa Teresa, coleção de L.Kollmann from Iporanga, 25 Febuary 2013 (fl.), L.Kollmann 12587, ( MBML!).

Distribution, habitat and phenology. Begonia langenbergiana is known from the South of Sao Paulo State, Brazil, growing on limestone rock covered by hygrophilous Atlantic Forest. The type locality consists of dense rain forest remnants of approximately 360 km ² between 50 and 1000 m elevation in the Parque Estadual Turistico do Alto Ribeiro (PETAR).

Flowers were observed from December to June; fruits from February to September.

Etymology. — The name of the new species pays a posthumous homage to Kingsley Frederick Langenberg, who made an important contribution to the American Begonia Society (ABS) and has long helped me in the correction of my English papers.

Conservation status. — Although part of the range of the new species is in a protected area, due to the apparent endemic distribution of B. langenbergiana , the low number of specimen collected, its approximate Extent of Occurrence estimated to be 16 km 2, and the approximate Area of Occupancy estimated at 344 km 2, it would seem prudent to include this species on the Endangered (EN) according to the IUCN (2017) criteria (B2ab(i,ii,iii)).

Taxonomical notes. — Begonia langenbergiana is closely related to B. itaguassuensis but differs by the lightly bullate leaves (vs. not bullate) with adaxially introse and abaxially prominent veins (vs. veins not adaxially introse and not abaxially prominent); the first flowers are erect and open when the inflorescence is small and still growing, until his maturity (vs. first flowers reflex and open when the inflorescence has just grown); the first ramifications of the inflorescences are erect when the inflorescence is growing until his maturity (vs. first ramifications of the inflorescences are reflex when the inflorescence is growing and erect at maturity); and its stigma are without a stigmatic band (vs. with a stigmatic band).

According to the sectional classification of Doorenbos et al. (1998) and Moonlight et al. (2018), B. langenbergiana belongs to Begonia section Pritzelia , which includes approximately 130 species from south America characterized by their entire placentae and the presence of cystoliths in the leaf cells.

Figures

FIGURE 1. Begonia langenbergiana. A. habit in the wild; B. stem of the plant, C. male flower; D. female flower; E. mature fruit. Photography’s by Harri Lorenzi (Figure 2(A)), and by L.Kollmann (Figure2(B,C,D,E)).

FIGURE 2. Begonia langenbergiana. A. habit; B. trichomes of abaxial face; C. trichomes of adaxial face; D stipule; E. bract; F. male flower; G. sepals (a) and petals (b) of male flower; H. stamen back view; I. stamen front view; J. prophyll; K. female flower side view; L. female flower front view; M. sepals (a) and petals (b) of female flower; N. stigma; O. fruit side view; P. seed (A-P: L.Kollmann 12587). Drawn by Joelcio Freitas.

FIGURE 3. Distribution map of Begonia langenbergiana (star).