Begonia santarosensis Kuntze

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 : 34-36

5.26. Begonia santarosensis Kuntze , Revis. Gen. Pl. 3(3): 106 (1898).

– Type: Bolivia, [Conchabamba Department, Prov. Chapare], Santa Rosa to Tiraque , [17 ° 16′S, 65 ° 48′W], 2600 m, 1–4 vi 1892, C.E.O. Kuntze s.n. (lectotype NY [ NY00118646 ] designated here, first stage designated in: Revista Univ. (Cuzco) 33(87): 82 (1944) by Smith, L.B. & Schubert, B.G.; isolectotype NY [ NY00118647 ]) .

L.B. Smith & B.G. Schubert, Revista Univ. (Cuzco) 33(87): 82 (1944); R.C. Foster, Contr. Gray Herb. 184: 138 (1958); D.C. Wasshausen et al. in P.M. JØrgensen et al. (eds), Cat. Bolivia, Monogr. Syst. Bot. Missouri Bot. Gard. 129: 386 (2013).

Caulescent herb, lacking a tuber or rhizome. Stem erect to semi-scandent, 30–400 cm tall, 1–4 mm in diameter, branching, internodes 50–125 mm, glabrous, dark red. Stipules persistent, triangular, 15–26 × 4–15 mm, apex acuminate, glabrous, red drying brown, margin entire, aciliate. Leaves alternate, basifixed; petioles joining blade at a right angle, 40–105 mm long, glabrous; blades asymmetrical, transversely ovate to transversely broadly ovate, 45–70 × 60–130 mm, apex long acuminate, base cordate, basal lobe to 22 mm, basal lobes not overlapping, venation palmate with 8–12 veins from the base, upper surface dark green, usually flushed red around the petiole insertion and margin, light green along the major veins, glabrous, lower surface dark red, glabrous, margin serrulate, ciliate. Inflorescences 1–3 per stem, axillary, erect, cymose, bearing up to 16 staminate and 16 pistillate flowers; peduncle to 12 cm long, glabrous, dark red; pedicels of staminate flowers held horizontally, to 8 mm long, dark red; pedicels of pistillate flowers to 28 mm long, glabrous, red; bracts deciduous, lanceolate to obovate, c.5 × 2 mm, apex rounded, red, glabrous, margin lacerate, ciliate. Staminate flowers: tepals 2, projecting, ovate, 8–10 × 4–6 mm, apex rounded, margin entire, glabrous, pink to red; stamens c.60, free, spreading, filaments c. 0.5–1 mm long, anthers symmetrically basifixed, linear, c. 1–1.5 mm long, dehiscing via lateral slits, connectives extended to 0.1 mm. Pistillate flowers: bracteoles 2, deciduous, broadly ovate, c.6 × 6 mm, apex rounded, red, glabrous, margin lacerate, ciliate; tepals deciduous in fruit, 5, subequal, spreading, elliptic to ovate, 12–14 × 5–7 mm, apex obtuse, margin entire, glabrous, dark pink to dark red; ovary body broadly ovoid, c.5 × 5 mm, glabrous, 3-winged, dark pink to dark red, one wing longer than the other two, oblong, rounded, c.13 × 8 mm, the smaller two wings semicircular, c. 2 mm wide, 3-locular, placentas bifid, bearing ovules on both surfaces; styles 3, yellow, free at base, irregularly multifid, stigmatic papillae in spirally twisted bands. Fruiting pedicel to 3.5 cm long; fruit nutant, body broadly ovoid, 6–12 × 6–10 mm, light brown, glabrous, wings same shape as in female flower, light brown, longest wing expanding to 15–30 × 8–12 mm tall, shorter wings not expanding.

Distribution and ecology. Begonia santarosensis is endemic to Bolivia and found in Cochabamba and Santa Cruz Departments. It is found within middle and upper montane forest at an elevation of 1040–3450 m. It is a semi-scandent species, typically found at the edge of montane forest. It has been collected in flower and fruit throughout the year.

Etymology. The type collection of this species was collected between Santa Rosa to Tiraque in Cochabamba Department of Bolivia. It is named for this locality.

Proposed IUCN conservation category. Begonia santarosensis has a relatively small range, and its EOO is c. 4500 km 2. This area is subject to some deforestation but still contains significant tracts of undisturbed montane forest. It has been collected frequently since the year 2000, including in Parque Nacional Amboro in Caballero Province, Santa Cruz Department. Accordingly, we assess Begonia santarosensis as Least Concern (LC) under IUCN criteria ( IUCN Standards and Petitions Subcommittee, 2019).

Additional specimens examined. BOLIVIA. Cochabamba Department: Km 104 camino Chapare, 3100 m, 14 xii 1966, R.F. Steinbach 612 ( NY) . Arani Province: El Limbo , 17 ° 8′38′′S, 65 ° 35′19′′W, 2180 m, 16 vi 2003, S. Altamirano, E. Zurita, T. Camacho, M. Aliaga & A. Lacaze JA913 ( MO). Chapare Province : Tablasmonte , a unos 110 km de la cuidad de Cochabamba, 17 ° 5′5′′S, 65 ° 56′33′′W, 2300 m, J. Terán, D. Souz & E. Rodríguez 3695 ( MO) ; 23.8 km N of Colomi (junction of the road to Candelaria) on road to the Chapare , then 2.2 km NW (left) on side road, upper río Cayani , 17 ° 10′S, 65 ° 53′W, 2700 m, 19 x 1985, J.C. Solomon 14393 ( LPB, MO) ; Zona del Sillar , km 92 a 1 km al este de la carrtera, 17 ° 11′44′′S, 65 ° 47′24′′W, 1040 m, 21 xi 2008, J. Terán, D. Soux & E. Rodríguez 3072 ( MO) ; El Cañadó n-Corani , zona muy próxima a la represa Corani a 60 km de la ciudad de Cochabamba, 17 ° 12′41′′S, 65 ° 12′18′′W, 3436 m, J. Terán, D. Soux & E.A. Rodríguez 836 ( MO). [ Ayopaya Province]: Incachaca , [17 ° 14′S, 65 ° 49′W], 2300 m, 2 iii 1929, J. Steinbach ( BM, E, G, K, MO) ; ibid., 2420 m, 15 viii 1950, W.M.A. Brooke 6734 ( BM, NY), faldas bosques del Cerro Incachaca , 3000 m, 20 x 1920, J. Steinbach 5012 ( G, NY) ; Incachaca oeste, 17 ° 14′3′′S, 65 ° 49′58′′W, 2600 m, J. Terán, D. Soux, M. Aliaga & E.A. Rodríguez 3998 ( MO). Carrasco Province: Sehuencas area , 17 ° 31′38′′S, 65 ° 15′17′′W, 2386 m, 21 ii 2003, L. Rico, T. Windsor-Shaw, A. McRobb & L. Alvarez 1314 ( K, MO, NY) ; 28 km al NE de Comarapa por el camino entre Santa Cruz y Cochabamba (20 km en línea recta al NE de Comarapa), 17 ° 49′S, 64 ° 41′W, 2450 m, 10 ii 1987, J.C. Solomon & M. Nee 15996 ( MO) ; Siberia , próximo a la carretera , 17 ° 49′40′′S, 64 ° 45′17′′W, 2986 m, 25 ix 2007, J. Terán, E.A. Rodríguez & D. Soux 1191 ( MO) ; 11 km ENE del pueblo de Siberia, 17 ° 50′S, 64 ° 42′W, 2600 m, 5 iii 1988, M. Saldias P. 289 ( NY [2]). Santa Cruz Department. Caballero Province: Khara Huasi , alrededores del pueblo y tramo de 1–2 km subiendo el río Chua Khocha, 17 ° 44′3′′S, 64 ° 44′5′′W, c. 1850 m, 20 vii 1996, I.G. Vargas C. 4850 ( NY) ; Old trail Pojo-Kara Huasi , c. 3 km NW of Locotal, 17 ° 46.12′S, 64 ° 45.62′W, 2200–2500 m, 2 ii 2000, B. Ståhl 5544 ( GB) ; Parque Nacional Amboró, Cerro Bravo, 15 km N of Comarapa, [17 ° 47′S, 64 ° 33′W], 2500 m, 23 v 1996, D.C. Wasshausen, R.K. Brummitt & J.R.I. Wood 2035 ( K, LPB) ; Amboro National Park, Cerro Bravo area , c. 10 km N of Comarapa, near permanent plot , 17 ° 49′5′′S, 64 ° 32′5′′W, 2500 m, 20 vi 1995, J. Abbott & A. Jardim 17105 ( G, MO) ; Astillero , 17 ° 49′26′′S, 64 ° 41′22′′W, 2550 m, 14 viii 2003, E. Fernández, S. Durán, D. Rivera, C. Patzi & A. Romero EF2029 ( LPB, MO) ; a 26 km de Comarapa, Carretera a Cochabamba , camino hacia el empalme, 17 ° 49′64′S, 64 ° 39′10′′W, 2650 m, 17 iv 2003, D. Soto, E. Calzadilla & M. Muñoz 56 ( MO) ; Entre el Empalme y Locotal , 17 ° 50′38′′–47′21′′S, 64 ° 41′34′′–43′10′′W, 2100–2850 m, 8 iv 2004, E. Calzadilla et al. 153 ( MO, NY). Florida Province: Comunidad de Bella Vista , quebrada que esta presente en el cerro la piedra bordada, 18 ° 17′35′′S, 63 ° 39′5′′W, 1520 m, 6 ii 2006, D. Villaroel, M. Vargas & F. Seidel 343 ( MO) .

Nomenclatural notes. Kuntze cited material collected between Santa Rosa and Tiraque in the protologue of Begonia santarosensis ( Kuntze, 1898) . Smith & Schubert (1944a) cited material in NY herbarium as the type, which is an effective first-stage lectotypification. We designate the sheet NY00118646 as the lectotype because it is the only sheet in NY with fruits. This sheet does, however, lack flowers, so further authors may wish to designate a fertile epitype.

Identification notes. Begonia santarosensis is most easily confused with B. juntasensis on account of the two species’ large, persistent stipules that become reflexed with age. Both species also have transversely ovate leaves. They are best distinguished by their venation. Begonia santarosensis has 8–12 prominent veins from the base and B. juntasensis has 2–5 veins from the base, which are much less prominent. We also suspect that the habits of the two species differ. Begonia santarosensis is frequently described as vine-like and reaches

4 m in height, whereas B. juntasensis rarely exceeds 50 cm in height.