Begonia ulmifolia Willd.

Moonlight, Peter. W., Jara-Muñoz, Orlando A., Purvis, David A., Delves, Jay, Allen, Josh P. & Reynel, Carlos, 2023, The genus Begonia (Begoniaceae) in Peru, European Journal of Taxonomy 881, pp. 1-334 : 116-120

26. Begonia ulmifolia Willd.

Figs 40 , 41

Species plantarum 4 (1): 418 ( Willdenow 1805). – Donaldia ulmifolia (Willd.) Klotzsch, Bericht über die zur Bekanntmachung geeigneten Verhandlungen der Königl. Preuss. Akademie der Wissenschaften zu Berlin 1854: 127 ( Klotzsch 1854).

– Type: VENEZUELA • Caracas, La Venta , “In America meridionali” ; F.W.H.A. von Humboldt 690; lectotype: B [ BW17571020 , BW17571010 ], designated by Smith (1973: 217); isolectotypes: P [ P01900835 , P00679511 ].

Link (1822: 396); Loddiges & sons (1822: pl. 638); Hooker (1823: t. 57); Humboldt et al. (1825: 179); Otto & Dietrich (1836: 356); Klotzsch (1855: 198); Walpers (1858: 908); de Candolle (1864: 290); Schulz (1911: 3); Smith & Wasshausen (1989: 44); Jacques & Mamede (2005: 585).

Begonia dasycarpa A.DC., Annales des Sciences Naturelles Botanique, Série 4 11: 127 ( de Candolle 1859).

– Type: BRAZIL – Bahia State • 1851; L. Dupasquier s.n.; lectotype: G-DC [F neg. 7324], designated here.

de Candolle (1861: 341, 1864: 291); Jacques & Mamede (2005: 585).

Begonia gesnerioides L.B.Sm. & B.G.Schub., Publications of the Field Museum of Natural History, Botanical Series 13 (4/1): 190 ( Smith & Schubert 1941a).

– Type: PERU – San Martín Region • Juanjuí, Alto río Huallaga ; [7°11′ S, 76°46′ W]; 400–800 m a.s.l.; Apr. 1936; G. Klug 4296; holotype: GH [ GH00068236 ]; isotypes: BM [ BM000832011 ], F [ V0042321F ], K [ K001089509 ], MO [ MO-2264384 ], NY [ NY03091036 ], P [ P05586479 ], S [ S04-727 ], U [ U0000718 ], UC [ UC709875 ], US [ US00115323 ]. Syn. nov .

Brako & Zarucchi (1993: 192); León & Monsalve (2006: 166).

Begonia jairi Brade, Arquivos do Jardim Botânico do Rio de Janeiro 10: 135 ( Brade 1950).

– Type: BRAZIL – Espírito Santo State • Estrada de Ferro Vitória-Minas Gerais , entre Boa Vista e Estação Pedro Palácio; J. Vieira & J. Mendoça 44; holotype: RB [ RB00536704 , RB00538019 ]; isotypes: HB .

Jacques & Mamede (2005: 585).

Etymology

Named for the superficial resemblance of the species’ leaves to those of species of elm ( Ulmus L., Ulmaceae ).

Specimens examined

PERU – San Martín Region: Prov. Huallaga • Cascadas de Shima , ca 45 minute walk towards waterfall from trail mouth; 6°53′56″ S, 76°50′07″ W; 521 m a.s.l.; 5 Feb. 2016; P.W. Moonlight & A. Daza 183; MOL, E [ E00885871 ] • ibid. 6°53′57″ S, 76°50′02″ W; 466 m a.s.l.; 5 Feb. 2016; P.W. Moonlight & A. Daza 184; MOL, E [ E00885870 ] .

Description

Caulescent herb, to 50 cm high. Stem erect, branching; internodes to 5 cm long, to 3 mm thick, succulent, brown, sparsely to densely tomentose. Stipules persistent, narrowly-lanceolate, 6–12 × 2–2.5 mm, apex acuminate, translucent, pale brown, glabrous, margin entire, aciliate. Leaves> 5, alternate, basifixed; petiole 1–2.5 cm long, brown, densely tomentose; blade asymmetric, oblanceolate, to 15 × 4.5 cm, membranaceous, apex broadly acuminate, base oblique, rounded on the broader side, cuneate on the narrow side, margin dentate to serrate, sparsely ciliate, upper surface green, pilose to sparsely pilose, lower surface pale green, sparsely tomentose, tomentose on the major veins pinnate, with 4–7 secondary veins on the larger side, 4–6 secondary veins on the smaller side. Inflorescences 1–3 per stem, bisexual, axillary, erect, cymose, with 4 branches, bearing up to 16 staminate flowers and 8 pistillate flowers, protandrous; peduncle to 7 cm long, red, tomentose, bracts persistent, elliptic, 3–8 × 0.5–1.5 mm, translucent, brown, glabrous, apex acuminate, aristate, margin entire, aciliate. Staminate flowers: pedicels to 10 mm long, sparsely tomentose; tepals 2, spreading, ovate, 8–9 × 5–7 mm, apex obtuse, white, tomentose on the outer surface, margin entire, aciliate; stamens ca 25, spreading, yellow, filaments 1–2 mm long, free, cuboid, ca 1 × 0.5 mm, dehiscing via lateral slits, connectives extending to 0.2 mm, symmetrically basifixed. Pistillate flowers: pedicels to 15 mm long; bracteoles 2, positioned directly beneath the ovary, lanceolate, 1–3.5 × 0.5 mm, apex truncate, translucent, green flushed red, glabrous, margin entire, aciliate; tepals 5, subequal, deciduous in fruit, spreading, ovate, 3.5–5 × 2–3.5 mm, apex obtuse, white, sparsely pilose on the outer surface, margin entire, aciliate; ovary body ovoid, 3.5–5 × 1.5–3 mm, white or green flushed red, tomentose, unequally 3-winged, the largest wing triangular, 4–6 × 2–4 mm, smallest rib-like ca 1 mm wide; 3-locular, placentae branches divided, bearing ovules between the laminae; styles 3, yellow, free, 1–2 mm long, once-divided, stigmatic papillae in a spirally twisted band. Fruiting pedicel to 15 mm long. Fruit body ovoid, to 9 × 6 mm, drying brown, wings same shape as in ovary, the largest expanding to 12 × 15 mm, the smallest expanding to 2 mm wide.

Proposed conservation assessment

Known from a single population in Peru but widespread and locally common in its extra-Peruvian distribution and found in numerous protected areas. We assess B. ulmifolia as Least Concern (LC), which replaces the Endangered (EN B1a) assessment of Begonia gesnerioides by León & Monsalve (2006).

Synonymy notes

Begonia gesnerioides is newly synonymised with B. ulmifolia herein. Prior to this publication, B. gesnerioides was known only from the type collection made in 1936. In preparation for this manuscript, we were able to visit the type locality and collect sterile individuals from this population. Phylogenetic work published by Moonlight et al. (2018) shows that this population is nested within B. ulmifolia and examination of the type, new collections, and the protologue of B. gesnerioides shows that it is indistinguishable from the broad circumscription of B. ulmifolia provided by Jacques & Mamede (2005). Accordingly, we synonymise B. gesnerioides with B. ulmifolia . Following Jacques & Mamede (2005), our circumscription of B. ulmifolia also includes B. dasycarpa A.DC. and B. jairi Brade.

Typification notes

The protologue of B. ulmifolia cites specimens collected “in America meridionali ” by F.W.H.A. von Humboldt but no herbarium or collection number ( Willdenow 1805: 418). This name was therefore in need of lectotypification. L.B. Smith (1973: 217) later cited a duplicate of the collection F.W.H.A. von Humboldt 690 held in B as the “ holotype ” of B. ulmifolia . In 1973, this citation was sufficient to merit an effective lectotypification. There are two sheets of this collection held in Berlin (BW17571020 and BW17571010) but as they are labelled as sheets one and two, they can both be considered the same duplicate and therefore the same lectotype.

A.P. de Candolle did not cite any specimens of B. dasycarpa in the protologue for this species, citing only “In Brasilae Prov. Bahiensi” ( de Candolle 1859: 127). It is therefore appropriate to designate a lectotype for this species. A.P. de Candolle (1864: 290) repeated the same citation with the addition of the collector name “Dupasquier” with no herbarium cited again. A specimen whose label includes the name Dupasquier is present in G herbarium (F neg. 7324). This specimen was collected in Bahia state in 1851 and is a good match for A.P. de Candolle’s description of B. dasycarpa , hence we designate it as the lectotype of this species. We note that the label of this specimen also includes the name “Mr Goudot” next to the date 1859. This is written in a different hand to the rest of the label so may mean that the specimen was sent to or from Mr Goudot in Paris in 1859. The same combination of “Dupasquier” and “Goudot” is written on the label of the type specimen of B. neocomensium A.DC. but has generally been interpreted as “Du Pasquin”. We believe this name refers to the Lyon botanist L. Dupasquier who made collections of several Begonia species in Bahia.

Identification notes

Within Peru, B. ulmifolia is superficially most similar to B. buddleiifolia , which also has straight, pinnately nerved leaves and a dense indumentum on its vegetative parts. When flowering, the two species can easily be distinguished by their inflorescence structure. Begonia ulmifolia has an axillary inflorescence, which is a symmetrical cyme, whereas B. buddleiifolia has a terminal inflorescence, which is thyrsoid and asymmetrical. Sterile specimens of B. buddleiifolia may be determined by the bullate leaf lamina, which contrasts with the smooth lamina of B. ulmifolia .

Distribution and ecology

Native to Trinidad and Tobago, Venezuela, Guyana, Colombia, and Brazil and introduced elsewhere. Within Peru, known from a single population in Huallaga Province, San Martín Region ( Fig. 40 ). Found in semi-deciduous forest at an elevation of 400–800 m a.s.l.; where it is found on stream sides.

Figures

Fig. 40. Distribution of Begonia sect. Donaldia (Klotzsch) A.DC. in Peru and surrounding countries, B. ulmifolia Willd. (red). Black lines indicate country borders, grey lines indicate major administrative divisions, blue lines indicate rivers, and shading indicates elevation.

Fig. 41. Reproduction of an illustration of Begonia ulmifolia Willd. by Joseph Swan from Exotic Flora 1: t. 57 (Hooker, 1823) from the copy at the Royal Botanic Garden Edinburgh.