Begonia pleiopetala A.DC.

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 : 170-174

37. Begonia pleiopetala A.DC.

Figs 3B , 4C , 6F , 7G , 52C , 55

Annales des Sciences Naturelles Botanique, Série 4 11: 121 ( de Candolle 1859).

– Type: PERU • Andibus ; J. McLean s.n.; holotype: K [ K000252037 ].

Smith & Schubert (1941a: 197, 1944: 83); Brako & Zarucchi (1993: 195); Vásquez et al. (2005: 112– 125); Wasshausen et al. (2014: 386); Tebbitt (2015: 484).

Begonia gracillima A.DC., Annales des Sciences Naturelles Botanique, Série 4 11: 120 ( de Candolle 1859).

– Type: PERU • 1839–1840; C. Gay s.n.; lectotype: P [ P00482219 ], designated by Tebbitt (2015: 484); isolectotype: G-DC ex P.

de Candolle (1864: 283); Smith & Schubert (1941a: 191); Brako & Zarucchi (1993: 192); León & Monsalve (2006: 166); Tebbitt (2015: 484).

Begonia pusilla A.DC., Annales des Sciences Naturelles Botanique, Série 4 11: 120 ( de Candolle 1859).

– Type: BOLIVIA – Prov. Yungas • Dec. 1846; H.A. Weddell 4215; lectotype: G-DC ex P [F neg. 7327], designated by Tebbitt (2015: 484); isolectotypes: P [ P00482207 , F neg. 38530].

Smith & Schubert (1944: 83); de Candolle (1864: 282); Tebbitt (2015: 484).

Begonia tenuicaulis A.DC., Annales des Sciences Naturelles Botanique, Série 4 11: 120 ( de Candolle 1859).

– Type: BOLIVIA – Prov. Larecaja • Caupolican, valées entre Tipoani et Apolobamba ; May 1847; H.A. Weddell 4592; lectotype: P [ P00482211 , F neg. 38533], designated by Tebbitt (2015: 484); isolectotype: G-DC ex P.

de Candolle (1864: 282); Tebbitt (2015: 484).

Begonia warburgiana Hieron., Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie 21: 325 ( Hieronymus 1895).

– Type: BOLIVIA – [La Paz Department] • Illimani, entre Pongo y Apacheta ; 3800 m a.s.l.; 17 Dec. 1876; A. Stübel 24b; lectotype: B [ B100186583 , F neg. 20908], designated by Smith & Schubert (1944: 84).

Smith & Schubert (1944: 84); Tebbitt (2015: 484).

Etymology

In common with other members of B. sect. Eupetalum , the staminate flowers of B. pleiopetala have more tepals than usual in the genus. The epithet derives from the Greek ‘ pleiōn ’ and ‘ petalos ’, meaning ‘more’ and ‘petals’.

Selected specimens examined

PERU – La Libertad Region: Prov. Pataz • Chigualen, above los Alisos ; [7°46′ S, 77°33′ W]; 21 Feb. 1986; K. Young 2892; HUT • Chigualen; [7°47′ S, 77°43′ W]; 21 Feb. 1986; K. Young 2878; HUT. – Ancash Region: Prov. Huaylas • Huascarán National Park Quebrada Parón ; 9°01′ S, 77°03′ W; 3500– 3760 m a.s.l.; D.N. Smith 10585; USM . – Huánuco Region: Prov. Pachitea • Dist. Umari. Comunidad campesina de San Marcos ; 9°54′11″ S, 76°06′30″ W; 3040 m a.s.l.; 4 Mar. 2010; H. Beltrán & L. Puelles 6762; USM. – Pasco Region: Prov. Oxapampa • Dist. Pozuzo, Parque Nacional Yanachaga-Chemillén , Estación Biológica Huampal , Quebrada Honda ; 10°10′59.5″ S, 75°34′37.7″ W, 1021 m a.s.l.; 29 Mar. 2017; A. Orejuela & J. Castillo 2914; USM • Dist. Oxapampa, Estación Biológica Huampa , Parque Nacional Yanachaga-Chemillén , camino a colones; 10°11’42.32”S, 75°35′16.8″ W; 1056 m a.s.l.; 27 Apr. 2012, R. Rojas, K. Durand, G. Shareva & R. Zehnder 8000; HOXA, USM • Road from Oxapampa to Pozuzo ; 1131 m a.s.l.; 10°11′14″ S, 75°54′37″ W; 1131 m a.s.l.; 21 Feb. 2016; P.W. Moonlight & A. Daza 297; E [ E00885875 ], MO, MOL • Junín Region: Prov. Tarma: Dist. Huasahuasi, camino hacia el centro poblado de San Lorenzo de Ninabamba ; 10°58′25.8″ S, 75°29′05.4″ W; 2000 m a.s.l.; 16 Mar. 2017; L. Valenzuela, J. Flores & S. Riva 31731; USM • Santuario Nacional de Pampa Hermosa ; 10°59′ S, 75°25′ W; 1400–1900 m a.s.l.; S. Riva, L. Valenzuela & J. Flores 135; USM. – Prov. Chanchamayo • Agua Blanca Canyon trail from Puente Azúcar ; ca 100 m on to trail, 10°11′32″ S, 75°27′18″ W; 1431 m a.s.l.; 16 Feb. 2016; P.W. Moonlight & A. Daza 257; E [ E00885473 ], MO, MOL. – Prov. Concepción • Dist. Comas, road from Comas to Satipo ; 11°29′43″ S, 75°52′05″ W; 3097 m a.s.l.; 13 Feb. 2016; P.W. Moonlight & A. Daza 230; E [ E00180311 ], MO, MOL • ibid., km 158 ; 11°29′28″ S, 74°48′16″ W; 1955 m a.s.l.; 13 Feb. 2016 l; P.W. Moonlight & A. Daza 236; E [ E00885475 ], MO, MOL. – Huancavelica Region: Prov. Tayacaja • Montepungo road , east of Surcubamba; [12°07′ S, 74°37′ W]; 2700 m a.s.l.; 13 Jan. 1939; H.E. Stork & O.B. Horton 10376; G, K. – Cusco Region: Prov. Urubamba • Dist. Ollantaytapata, Garrapatal , Pajonal ; 13°04′57″ S, 72°16’57′ W; 3382 m a.s.l.; 25 Feb. 2006; L. Valenzuela, J. Farfán, E. Suclli, I. Huamantupa & R. Ayerbe 6364; K, MO [ MO-2183895 ], US [ US00951221 ], USM • Arriba de Machu Picchu Pueblo , Aguas Calientes , por los rieles del tren que conducen a Ollantaytambo, orilla del río Urubamba; 13°10′28.8″ S, 72°31′37.3″ W; 2078 m a.s.l.; 20 Mar. 2017; A. Orejuela & J. Castillo 2884; E [ E01007465 ], USM • Dist. Machu Picchu, Wiñay Wayna ; 13°13’40′ S, 72°30′23″ W; 2700–3923 m a.s.l.; 21 Feb. 2003; L. Valenzuela, E. Suclli, I. Huamantupa & A. Carazas 1472; MO [ MO-346339 ]. – Prov. La Convención • Dist. Huayopata, San Luis ; 13°04′43″ S, 72°23′25″ W; 2900 m a.s.l.; 22 Mar. 2003; G. Calatayud, I. Huamantupa, E. Suclli, J. Farfán, A. Carazas & Y. Vizcardo 1319; MO [ MO-300883 ] • Dist. Huayopata, along 28b between Santa Maria and Ollantaytambo; 13°05′ S, 72°22′ W; 3392 m a.s.l.; 7 Feb. 2015; M.C. Tebbitt & A. Daza 803; E [ E01059315 ], USM • Dist. Huayopata, Abra de Málaga ; 13°08′20″ S, 72°18′16″ W; 3700 m a.s.l.; 3 Dec. 2003; L. Valenzuela, E. Suclli, E. Acurio & R. Bonino 2418; MO [ MO-1664174 ], US [ US00900534 ]. – Ayacucho Region: Prov. Chincheros • Cangallo , 2 km past Ocros on road to Ayacucho; [13°22′ S, 73°47′ W]; 18 Apr. 1971; J.G. Hawkes 5231; C. – Puno Region: Prov. Sandia • Limbani ; [14°09′ S, 69°41′ W]; 3200 m a.s.l.; 22 Nov. 1938; J.C. Vargas Calderón 1317; MO [ MO-1641355 ] • SW corner of río Awi-Awi and río Cuyo-Cuyo ; 14°08′ S, 69°32′ W; 3250 m a.s.l.; 31 Jan. 1986; B. Bennett 2073; NY [ NY01149161 ] • Dist. Cuyocuyo, between Cuyocuyo and Sandia; 15°26′ S, 69°33′ W; 3789 m a.s.l.; M.C. Tebbitt & A. Daza 813; E [ E01059314 ], MOL, USM.

Description

Acaulescent, tuberous herb, to 25 cm high. Tuber spheroid, 1–4 × 1–4 cm, with 1 growing point. Stipules persistent, triangular, 2–5 × 2–4 mm, apex acute, opaque, dark brown, glabrous, margin entire, aciliate. Leaves 2–8, alternate, basifixed; petiole 1–12.5 cm long, red, sparsely to densely tomentose; blade subsymmetric, reniform to ovate, to 15 × 11 cm, succulent, apex indistinct, rounded, to obtuse, base truncate to cordate, basal lobes overlapping or not overlapping, sinus to 25 mm deep, margin undulate, crenate, or dentate, aciliate to ciliate, upper surface green, glabrous to pilose or villous, lower surface very pale green with red veins, glabrous to sparsely pilose on the lamina, sparsely to densely pilose or villous on the veins, veins palmate, 5–8 veined from the base. Inflorescences 1–4, bisexual, axillary, erect, a dichasial or monochasial cyme, with 2 branches, bearing up to 2 staminate flowers and 2 pistillate flowers, protandrous; peduncle to 21 cm long, white to green or red, sparsely tomentose, bracts late deciduous, lanceolate, 4–10 × 1–5 mm, translucent, pale green, glabrous, sparsely tomentose on the outside, apex acute, margin entire, sometimes serrulate at the apex, aciliate to ciliate. Staminate flowers: pedicels to 45 mm long, sparsely tomentose; tepals 5–11, projecting, lanceolate, 5–25 × 1–13 mm, apex rounded, white to pink, rarely red, glabrous, sometimes lanate on the outside, margin entire, aciliate; stamens 15–50, spreading, yellow, filaments 0.5–2.5 mm long, free, anthers ellipsoid, 1–1.5 × 0.5– 0.8 mm, dehiscing via lateral slits, connectives not extending or extending to 0.75 mm, symmetrically basifixed. Pistillate flowers: pedicels to 55 mm long; bracteoles lacking; tepals (4–)5–10, subequal, persistent in fruit, spreading, elliptic to ovate, 4–10 × 1–10 mm, apex rounded to truncate, white to pink, rarely red, glabrous, sparsely tomentose outside, margin entire, aciliate; ovary body ovoid, 2–8 × 2–7 mm, white to green or red, sparsely to densely tomentose, unequally 3-winged, rarely 2-winged, the largest wing triangular to rectangular, sometimes ascending, 2–8 × 2–10 mm, the smallest marginal, 0.5–1 mm wide; 3-locular, rarely 2-locular, placentae branches divided, bearing ovules on both surfaces; styles 3, rarely 2, yellow, free, 2–4 mm long, 2- to 4-lobed, stigmatic papillae in a spirally-twisted band. Fruiting pedicel to 55 mm long. Fruit body ovoid, to 9 × 8 mm, drying brown, wings same shape as in ovary, the largest expanding to 9 × 14 mm, the smallest expanding to 1.5 mm wide.

Proposed conservation assessment

Recently assessed as Least Concern (LC) by Tebbitt (2016).

Notes

The specimen C. Díaz 2481ª is B. pleiopetala but the label data describes a locality in lowland Amazonian forest in Loreto Region that is unsuitable for this species. We include the specimen H. Beltrán & L. Puelles 6762 in this species, though it differs from all other specimens in its larger, red flowers. It may represent an undescribed species, but the material is insufficient for description.

Typification notes

Tebbitt (2015) attempted to designate the specimen A. Stübel 24B as the lectotype of B. warburgiana Hieron. However, Smith & Schubert (1944) has already cited this specimen as the type of the name, which is an effective lectotypification. Tebbitt’s lectotypification was superfluous.

Identification notes

A variable species that differs greatly in its size, the thickness of its leaves, and its indumentum across its elevational range. Most similar to B. octopetala but with fewer stamens (<50 vs> 50) and usually a much smaller plant with smaller flowers and narrower tepals, though the two species overlap fully in these characters.

Distribution and ecology

Known from Peru and Bolivia. Within Peru, known from La Libertad, Ancash, Huánuco, Pasco, Junín, Huancavelica, Cuzco, Apurimac, and Puno Regions ( Fig. 52C ). Found in lower, middle, and upper montane forest and high elevation grasslands at an elevation of 946–3950 m a.s.l. In the lower parts of its elevational range, B. pleiopetala is typically found on cliff faces and at higher elevations it is found among rocks and growing on grassy slopes. The species is a geophyte and dies down to its tuber in the dry season. The species flowers in the wet season, which is mostly from December to March.

Figures

Fig. 3. Inflorescence structure in Peruvian Begonia. A. Axillary, dichasial cyme, with central, staminate flowers, B. glabra Aubl. B. An axillary (leaf axis not shown) monochasial cyme, B. pleiopetala A.DC. C. A terminal, thyrsoid inflorescence, composed of lateral dichasia reducing in size towards the apex of the inflorescence, B. rossmanniae A.DC. Photographs taken by D.A. Purvis & P.W. Moonlight in the living collections of the Royal Botanic Garden Edinburgh.

Fig. 4. Staminate tepal number in Peruvian Begonia. A. A single, equal pair of tepals, B. bracteosa A.DC. B. An outer pair of tepals held perpendicular to a smaller, inner pair of tepals, B. buddleiifolia A.DC. C. Ten tepals in a member of the octopetala group of B. sect. Eupetalum (Lindl.) A.DC., B. pleiopetala A.DC. Photographs taken by D.A. Purvis in the living collections of the Royal Botanic Garden Edinburgh.

Fig. 6. Styles and stigmas in Peruvian Begonia. A–C. Bifid styles. D. Reniform styles. E–F. Irregularly multifid styles. A. Three styles and stigmas of B. bracteosa A.DC. B. Three styles and stigmas of B. glabra Aubl. C. Single style and stigma of B. yuracyacuensis Moonlight sp. nov. D. Three styles and stigmas of B. pedemontana Moonlight sp. nov. E. Three styles and stigmas of B. obtecticaulis Irmsch. F. Single styles and stigma of B. pleiopetala A.DC. Photographs taken by D.A. Purvis & P.W. Moonlight in the living collections of the Royal Botanic Garden Edinburgh.

Fig. 7. Placentation in Peruvian Begonia. A–D. Axillary placentation with undivided branches. E–H. Axillary placentation with divided branches. A. B. buddleiifolia A.DC. B. B. foliosa Kunth. C. B. glabra Aubl. D. B. joshii Moonlight. E. B. albomaculata C.DC. F. B. rossmanniae A.DC. G. B. bracteosa A.DC. H. B. pleiopetala A.DC. Photographs taken by D.A. Purvis & P.W. Moonlight in the living collections of the Royal Botanic Garden Edinburgh.

Fig. 52. Distribution of the octopetala group of Begonia sect. Eupetalum (Lindl.) A.DC. in Peru and surrounding countries. A. B. anemoniflora Irmsch. (red) and B. tumbezensis Irmsch. (blue). B. B. octopetala L.Hér. subsp. octopetala (red) and B. octopetala subsp. ovatiformis Irmsch. (blue). C. B. pleiopetala A.DC. (red) and B. pseudopleiopetala Tebbitt (blue). D. B. polypetala A.DC. (red). Black lines indicate country borders, grey lines indicate major administrative divisions, blue lines indicate rivers, and shading indicates elevation.

Fig. 55. Begonia pleiopetala A.DC. A. Habit. B. Section of inflorescence and bracts. C. Leaf, adaxial surface. D. Leaf, abaxial surface. E. Tuber. F. Staminate flower, side view. G. Staminate flower, front view. H. Staminate flower, back view. I. Smallest tepal of staminate flower. J. Largest tepal of staminate flower. K. Androecium, side view. L. Pistillate flower, side view. M. Pistillate flower, front view. N. Pistillate flower, back view. O. Cross section of ovary. P. Smallest tepal of pistillate flower. Q. Largest tepal of pistillate flower. R. Pistils, side view. S. Pistil, side view. All photographs taken by D.A. Purvis in the living collections of the Royal Botanic Garden Edinburgh (Accession 20160140, grown from seeds collected as part of P.W. Moonlight & A. Daza 236).