Begonia alchemilloides Meisn. ex A.DC.

Moonlight, Peter & Fuentes, Alfredo F., 2022, AN UPDATED CHECKLIST AND KEY TO THE SPECIES OF BOLIVIAN BEGONIA, INCLUDING ONE NEW SPECIES, Edinburgh Journal of Botany 79 (407), pp. 1-66 : 22-24

3.16. Begonia alchemilloides Meisn. ex A.DC. , Ann. Sci. Nat. Bot. IV(11): 125 (1859).

– Type: Brazil, Minas Gerais State, in camporum editorum runcationibus, ad Sera, Serro Frio , C.F.P. von Martius s.n. (lectotype M [ M0009906 ] designated here).

A.P. de Candolle, Fl. Bras. 4: 344 (1861).

Caulescent herb, lacking a tuber or rhizome but sometimes with a swollen, tuber-like base to the stem, c.20 × 10 mm, rooting from the lower nodes. Stem erect, 5–10 cm tall, 1–3 mm in diameter, rarely branching, internodes 3–15 mm, sparsely villous, pale green. Stipules tardily deciduous, triangular to broadly ovate, 3–4 × 2.5–3 mm, apex acute, mucronate, glabrous, light brown, margin serrulate, ciliate. Leaves alternate, basifixed; petioles joining blade at a slight angle, 4–15 mm long, sparsely villous; blades subsymmetrical, reniform to ovate, 10–25 × 15–35 mm, apex rounded, base truncate to cordate, basal lobes to 5 mm, not overlapping the petiole, venation palmate, 7 or 8 veins from the base, upper surface green, glabrous to sparsely villous, lower surface pale green, sparsely villous, margin crenate to dentate, ciliate. Inflorescences 1–3 per stem, axillary, erect, arising close to the apex of the stem, a dichasial cyme, protandrous, with up to 4 staminate flowers and 2 pistillate flowers; peduncle 15–25 mm long, glabrous, pale green; pedicels of staminate flowers 3–5 mm long, glabrous, pale green; pedicels of pistillate flowers 5–7 mm long, glabrous, pale green; bracts persistent, obovate, 1.5–2 × 1.5–2 mm, apex obtuse, pale green, glabrous, margin lacerate, ciliate. Staminate flowers: tepals 4, spreading, white, the inner two obovate, 4–5 × 2.5–3 mm, apex rounded, base cuneate, margin entire, glabrous, the outer two orbicular, c.6 × 6 mm, apex rounded, margin entire, glabrous; stamens 4–6, fused at the base, projecting, filaments 0.25–0.5 mm long, anthers symmetrically basifixed, oblong, 1–1.5 mm long, dehiscing via lateral slits, connectives extended c. 0.1 mm. Pistillate flowers: bracteoles 3, c. 1 mm below the ovary, persistent, oblanceolate, 4–6 × 1–2 mm, apex rounded, white, glabrous, margin lacerate, ciliate; tepals tardily deciduous in fruit, 5, spreading, obovate, 6–7 × 2–4.5 mm, apex obtuse to rounded, margin entire, aciliate, glabrous, white; ovary body broadly ovoid, 3–3.5 × 2–3.5 mm, pale green, 3-winged, wings pink, one wing longer than the other two, triangular, ascending, front edge truncate, apex acute, lower edge straight, c.5 × 4 mm, the shorter two wings triangular, front edge truncate, apex rounded, lower edge gently curved, c.4 × 2 mm, 3-locular, placentas bifid, bearing ovules on both surfaces; styles 3, yellow, free at base, c. 2.5 mm long, bifid from around half their length, stigmatic papillae in a spirally twisted band. Fruiting pedicel to 8 cm long; fruit held erect, body ovoid, c.5 × 6 mm, light brown, glabrous, wings same shape as in pistillate flower, light brown, longest wing expanding to 7 × 6 mm, shorter two wings expanding to 6 × 5 mm.

Distribution and ecology. This is the first record of a species previously thought to be endemic to Brazil, where it has been collected in Goías and Minas Gerais States ( Brazil

Flora Group, 2015). The disjunction between the Cerro Manomó and the closest Brazilian populations is c. 935 km, which is very large in the context of Begonia species. The habitats in the Brazilian and Bolivian parts of its range are remarkably similar. Most Brazilian collections have been made in shaded rock outcrops or ravines in areas of Central Brazilian Cerrado; for example, see the collection P.W. Moonlight 1909 on the Begonia Resource Centre database ( Hughes et al., 2015 –) for images of typical habitat. The collection J.R.I. Wood & D. Soto 26405 was made from a population growing in cracks in humid rocks in an area of Cerrado. This is the type locality of Mikania manomoi D.J.N.Hind & Frisby , which was collected by John R.I. Wood and J. Soto on the same day as this record ( Hind & Frisby, 2014). We refer to the protologue of Mikania manomoi for a full habitat description ( Hind & Frisby, 2014).

Additional specimen examined. BOLIVIA. Santa Cruz Department. Velasco Province: Cerro Manomó, aproximadamente 100 km al norte de San Ignacio de Velasco , 15°30′18′′S, 60°41′50′′W, 506 m, 12 xi 2009, J. R. I Wood & D. Soto 26405 ( K, LPB) .

Nomenclatural notes. The protologue of Begonia alchemilloides Meisn. ex A.DC. cited material collected by von Martius in Minas Gerais State in Brazil but cited no herbarium, so there is no holotype (see Article 9.1 of the Shenzhen Code; Turland et al., 2018). There is a sheet that matches de Candolle’s description in Munich herbarium (M0009906). This sheet was determined by de Candolle, who also cited material in ‘hb. reg. Monac.’ as Begonia alchemilloides in his revision of Brazilian Begonia ( de Candolle, 1861) . This does not constitute a type designation, because he did not use the word ‘type’ or equivalent in his citation (see Article 7.11 of the Shenzhen Code; Turland et al., 2018). Jacques & Mamede (2005) cited this collection as the holotype, which also does not count as an effective type designation, because since 2001 it has been mandatory to include the phrase ‘designated here’ or equivalent (see Article 7.11 of the Shenzhen Code; Turland et al., 2018). We designate the sheet M0009906 as the lectotype of Begonia alchemilloides .

Identification notes. Like all members of Begonia sect. Ephemera , B. alchemilloides is a delicate herb with palmately nerved leaves. It is best distinguished from other Bolivian species in the section by its subsymmetrical, reniform to broadly ovate leaves.