Begonia pseudopleiopetala Tebbitt

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 : 177-178

39. Begonia pseudopleiopetala Tebbitt

Fig. 52C

Novon 23 (4): 486 ( Tebbitt 2015).

– Type: PERU – Cajamarca Region: Contumazá • ca 20 km S of Contumazá, ca 18jm above Cascas; 7°25′ S, 78°25′ W; 2160–2200 m a.s.l.; 14 Apr. 1986; M.O. Dillon, D. Dillon & A. Sagástegui A. 4528; holotype: F [ V0360785F ]; isotypes: GB [ GB0058014 ], US [ US00431510 ].

Etymology

This species is easily confused with B. pleiopetala and the epithet reflects this.

Selected specimens examined

PERU – Piura Region: Prov. Huancabamba • Canchaque; [5°22′ S, 79°36′ W]; 1300–1500 m a.s.l.; 22 Mar. 1948; R. Ferreyra 3134; USM. – Cajamarca Region: Prov. Contumazá • Santiago Guzmango ; [7°22′ S, 78°54′ W]; 2100 m a.s.l.; 6 May 1965; A. Sagástegui A. & M. Fukushima 5070; HUT, US [ US00222211 ] • El Túnel , Cascas-Contumazá ; [7°24′ S, 78°48′ W]; 2700 m a.s.l.; 6 Apr. 1985; A. Sagástegui A., M. Guzmán, S. Leiva G. & C. Tellez A. 12629; HUT • Bosque Cachil ; [7°26′ S, 78°49′ W]; 2500 m a.s.l.; 16 Jun. 1994; A. Sagástegui A., S. Leiva G. & P. Lezama 15405; NY . – La Libertad Region: Prov. Gran Chimú • Cascas-Contumazá ; [7°25′ S, 78°47′ W]; 2250 m a.s.l.; 19 May 1962; A. López, A. Sagástegui A. & I. Sánchez 3678; HUT • Dist. Cascas, road between Cascas and Contumazá; 7°25′33″ S, 78°47′07″ W; 2007 m a.s.l.; 23 May 2015; M.C. Tebbitt & A. Daza 826; E, MOL.

Description

Acaulescent, tuberous herb, to 40 cm high. Tuber ellipsoid, 0.8–1.3 × 0.5 cm, with 1 growing point. Stipules persistent, triangular, 2–3 × 1.5–2 mm, apex acuminate, aristate, opaque, brown, glabrous, margin entire, aciliate. Leaves 1–5, alternate, basifixed; petiole 3.5–11(–50) cm long, pale pink, glabrous to densely pubescent; blade sub-symmetric, ovate, to 6 × 6.5 cm, succulent, apex acuminate, base cordate, basal lobes not overlapping, sinus to 15 mm deep, margin denticulate to dentate, glabrous to ciliate, upper surface green, sparsely to densely pilose, lower surface pale green, glabrous, pubescent on the major veins, veins palmate with one major vein, 5–6 veined from the base, with 1–3 secondary veins on the larger side, 1–3 secondary veins on the smaller side. Inflorescences 1 per plant, bisexual, axillary, erect, a dichasial or monochasial cyme, with up to 3 branches, bearing up to 3 staminate flowers and 2 pistillate flowers, protandrous; peduncle to 65 cm long, pink, sparsely to densely pubescent, bracts persistent, elliptic to ovate, 2.5–11 × 1.5–8 mm, opaque, pink, glabrous, pubescent beneath, apex acute, margin entire, aciliate. Staminate flowers: pedicels to 40 mm long, sparsely to densely pubescent; tepals 7–8, spreading, obovate to elliptic, 13–19 × 5–11 mm, apex obtuse to rounded, white, glabrous, outer surfaces sparsely pubescent, margin entire, aciliate; stamens ca 100, spreading, yellow, filaments 1.5–3 mm long, fused at the base, anthers obovate, ca 1 × 0.5 mm long, dehiscing via lateral slits, connectives extended, symmetrically basifixed. Pistillate flowers: pedicels to 32 mm long; bracteoles lacking; tepals 5, subequal, persistent in fruit, spreading, ovate to obovate, 8–17 × 2–7 mm, apex obtuse to rounded, white, glabrous, margin entire, aciliate; ovary body obovoid, 3–8 × 2–7 mm, pale green to pink, pubescent, unequally 3-winged, largest wing rectangular, 8–15 × 5–11 mm, smallest rib-like, 1–3 mm wide; 3-locular, placentae branches divided, bearing ovules on both surfaces; styles 3, yellow, free, 4–6 mm long, irregularly 3 to 5 times-divided, stigmatic papillae in a spirally twisted band. Fruiting pedicel to 35 mm long. Fruit body obovoid, to 8 × 7 mm, drying brown, wings same shape as in ovary, the largest expanding to 17 × 10 mm, the smallest expanding to 3 mm wide.

Proposed conservation assessment

Assessed by Tebbitt (2015) as Data Deficient (DD).

Notes

Tebbitt (2015) described B. pseudopleiopetala to encompass specimens from Piura, Cajamarca and La Libertad Regions that superficially resembled B. pleiopetala but with several consistent differences. Begonia pseudopleiopetala had acuminate (vs rounded to acute) leaf apices; obovate (vs elliptic to oblong) anthers lacking extended connectives; and 5 tepals on the pistillate flowers (vs 7–9). We have since collected several specimens of B. pleiopetala from central Peru (Pasco and Junín Regions) that share several of these characteristics. All were collected from <2000 m a.s.l. in elevation on seasonally wet cliffs in lower and middle montane forest rather than the species usual high elevation grassland habitat. These specimens variously have acuminate leaf apices (P.W. Moonlight & A. Daza 236, 257); anthers lacking extended connectives (P.W. Moonlight & A. Daza 236, 257); as few as 4 tepals on the pistillate flower (P.W. Moonlight & A. Daza 295, 297); and other unusual characters including two-locular ovaries (P.W. Moonlight & A. Daza 295, 297); but no individual has more than two of these characters. These characters may be the result of stress in marginal habitats, but limited evidence suggests this is not the case. Seed collected from the collection P.W. Moonlight & A. Daza 236 grown at the Royal Botanic Gardens Edinburgh retained the acuminate leaf apices and anthers lacking extended connectives of its parent plant (see Fig. 55 ), suggesting these characters are not simply a response to atypical growing conditions in the wild. None of these specimens have all four of the characteristics used by Tebbitt to separate B. pseudopleiopetala from B. pleiopetala so we retain it as a different species but suggest further genetic and morphological work may be required to determine whether they should be retained as separate species.

Identification notes

Begonia pseudopleiopetala differs from B. pleiopetala in its leaves with an acuminate apex (vs rounded to acute and rarely acuminate), its pistillate flowers with five tepals (vs [5–]7–9 tepals), and its obovate (vs elliptic to oblong) anthers with non-extended (vs non-extended to extended) connectives. Some specimens of B. pleiopetala share one or rarely two of these characters (see Notes) but no known specimens share all four characters.

Distribution and ecology

Endemic to Peru and known from Piura, Cajamarca, and La Libertad Regions ( Fig. 52C ). Found within northwest Peruvian relict montane forest at elevations from 1300–2500 m a.s.l. Begonia pseudopleiopetala is a geophytic species and dies down to its tuber in the dry season. It flowers during the wet season in March to June.

Figures

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).