Begonia micheliniana L. Kollmann, 2019

Kollmann, Ludovic Jean Charles, 2019, NOVELTIES IN BRAZILIAN BEGONIACEAE I: two new species from Bahia, Phytotaxa 404 (2), pp. 65-73 : 66-69

1. Begonia micheliniana L. Kollmann , sp. nov. ( Figs. 1 , 2 , 5 ).

Begonia micheliniana is closely related to B. polygonifolia and B. fagifolia in its climbing scandent species, persistent stipule, white flower, but can be distinguished to B. polygonifolia by its lanceolate, rarely elliptical leaf blades (versus elliptical to oblanceolate), its petioles reaching 4.5–12.5 cm (versus 0.2–1.7 cm), and it can be distinguished to B. fagifolia by lanceolate to rarely elliptical leaf blades (versus ovate), and its adaxially glabrous and deciduous bracts (versus adaxially hirsute and persistent).

Type:— BRAZIL. Bahia: Igrapiunã, Fazenda Michelin , 200 m elevation, 13°49’S 39°13’W, 18.febrery.2011 (fl., fr.), L. Kollmann, E. Leme & P. Lima 12182 (Holotype: MBML [ MBML53014 ]!; Isotypes: CEPEC!, RB!) .

Herbaceous, climbing, to 7m high, simple trichomes. Stems 5–7 mm diam. rooting at the nodes, internodes 4–7 cm long, green to reddish, lenticellate. Stipules persistent, 2.3–2.5 × 0.7–1.1 cm, greenish to reddish, translucent, asymmetrical, triangulate to falcate, lenticellate, apex acute to mucronate, base asymmetrical, margins entire, abaxial face carinate, papiraceous when dry. Petioles 4.5–12.5 cm long, green to reddish, lenticellate, glabrous, hairy at the apex, adaxial face sulcate. Lamina 11.5–20.8 × 2–6.8 cm, asymmetrical, lanceolate, rarely elliptical, adaxial face dark-green, abaxial face reddish to red-wine, apex acute, base obovate to acute, margins sparcialy serrulate, venation pinnate, veins adaxially introse, abaxially prominent, base of the abaxial face with a tuft of trichomes, stomata clustered. Inflorescences with 4– 7-dichotomous cymes, 28–35 cm long, whitish to reddish, lenticellate; bracts deciduous, 1–3 × 0.2–0.5 mm, greenish, translucent, triangulate, apex acute, glabrous. Staminate flowers: pedicels 4–9 mm long, white to pinkish, flattened, glabrous; 2-sepals, ca. 5 × 4 mm, white to pinkish, concave, obovate to orbiculate, apex rounded, margins entire, revolute; 2-petals, ca. 4.5 × 2 mm, white to pinkish, concave, obovate, apex obtuse, margins entire; stamens ca. 30, yellow, filaments 1–1.8 mm long, anthers 1–1.3 mm long, rimose, obovate, dehiscing by longitudinal slits, connective slightly projecting, apex obtuse to rounded. Pistillate flowers: pedicels 1–1.2 cm long, white, flattened, glabrous; prophylls 1–2, ca. 0.6 × 0.1 mm, white, triangulate, apex acute; 2-sepals, 3–4 × 1.5–2 cm, white, elliptical, apex acute; 3-petals, 7 × 4–4.5 mm, white, unequal, apex acute, one concave, obovate, two flattened, falcate to oblong; ovary 3- locular, axile placentation, one placentae per locule, ovules on both sides of placentae; 3-styles, 4–5 × 2 mm, yellow, united at base, each bifurcate, band of stigmatic papillae. Capsules ca. 2 × 9 mm, basally dehiscent, 3-wings, unequal, white to reddish, larger one 1–1.1 × 0.8–2 cm, smaller two 0.8–1 × 0.2–0.5 cm. Seeds ca. 0.7 × 0.25 mm, cylindrical, apex and base truncate.

Paratype:— Brazil.– Bahia: Igrapiunã, Fazenda Michelin, 200 m elevation, 13°49’S 39°13’W, 18.II.2011, fl., fr., L. Kollmann 12184, E. Leme & P. Lima (MBML [ MBML 53015]!).

Distribution, habitat and phenology. Begonia micheliniana is known from coastal low-elevation slopes (40 to 250 m elevation) covered by hygrophilous Atlantic Forest of Bahia state. Begonia micheliniana climbs on the trunk of the trees to a height of seven meters. Flowers were observed from December to June, fruits from February to September.

Conservation status:— Due to the apparent endemic distribution of B. micheliniana , with extent of occurrence estimated to be less than 10 km 2 and considering the high levels of deforestation and land use changes across its range it would seem prudent to classify the species as Critically Endangered (CR) (B2ab(iii)) due to the low number of known locations and decline in quality of habitat ( IUCN 2017).

Etymology:— The name of the new species pays homage to Michelin family, proprietors of the “ Plantações Michelin Bahia ” in Bahia state, Brazil, who continue to help protect a forest fragment in the important forests of southern Bahia state.

Notes:— The type locality is composed by dense rain forest remaining between areas of rubber tree ( Hevea brasiliensis) plantations. The “Plantações Michelin Bahia ” contains about 3,000 hectares of protected native forest, 1,000 hectares of rubber tree culture and an important social project.

Begonia micheliniana is closely related to B. polygonifolia and B. fagifolia in its climbing scandent habit, persistent stipules and white flower, but can be distinguished from B. polygonifolia by lanceolate to rarely elliptical leaf blade (vs. elliptical to oblanceolate), its 4.5–12.5 cm long petiole (vs. 0.25–2.5 cm long), and it can be distinguished from B. fagifolia by lanceolate to elliptical leaf blade (vs. ovate to lanceolate), and its adaxially glabrous (vs. hirsute) and deciduous bracts (vs. persistent).

According to the sectional classification of Doorenbos et al. (1998), and Moonlight et al. (2018) Begonia micheliniana is nested within section Wageneria (Klotzsch) A.DC. This group of species share a climbing habit and stems that produce adventitious roots at the nodes, symmetrical or subsymmetrical leaf blades that are pinnately or palmately veined, stamens with filaments slightly united below and anthers that are usually much shorter than the filaments, and cylindrical seeds crowned with a group of larger cells at the truncate apex.

Figures

FIGURE 1. Begonia micheliniana. A. habit in the wild; B. habit with male and female flowers, C. male flower; D. female flower front view; E. female flower side view.

FIGURE 2. Begonia micheliniana. A. habit; B. leaf; C. stipule; D. bract; E. male flower front view; F. male flower side view; G. sepals (a) and petals (b); H. stamen; I. sepals (a) and petals (b) of female flower, J. stigma; K. fruit side view; L. seeds (A-L: L.Kollmann 12182).

FIGURE 5. Distribution map of Begonia micheliniana (square); B. charlesjarosiana (star)