Capsicum piuranum Barboza & S.Leiva, PLOS One 14(1): 14. 2019.

Barboza, Gloria E., Garcia, Carolina Carrizo, Bianchetti, Luciano de Bem, Romero, Maria V. & Scaldaferro, Marisel, 2022, Monograph of wild and cultivated chili peppers (Capsicum L., Solanaceae), PhytoKeys 200, pp. 1-423 : 1

35. Capsicum piuranum Barboza & S.Leiva, PLOS One 14(1): 14. 2019.

Figs 101 , 102

Type.

Peru. Piura: Prov. Huancabamba, borde de carretera y riachuelo, 5°22'46"S, 79°33'47"W, 2311-2459 m elev., 22 Mar 2011, T. Mione 812 (holotype: CORD [CORD00006936]; isotype: NY [03231447]) .

Description.

Erect shrubs 2-2.20 (-3) m tall, densely branched above, the branches scandent. Young stems angled, fragile, flexuous, green, glabrous and shiny; bark of older stems green to dark brown, angled, glabrous; lenticels absent. Sympodial units difoliate, the leaves geminate; leaf pair markedly unequal in size and similar or dissimilar in shape. Leaves membranous, discolorous, dark green and shiny adaxially, light green and opaque abaxially, the mid-vein and primary veins raised abaxially, glabrous or both surfaces with sparse antrorse, simple, 4-5-celled, eglandular trichomes 0.5-1.2 mm long, occasionally trichomes more abundant on main veins and margins; blades of major leaves (8-) 12-17.7 cm long, (2-) 2.5-4.5 cm wide, elliptic, the major veins 7-9 on each side of mid-vein, the base asymmetric and attenuate, the margins entire, the apex long-acuminate; petioles 0.7-1.4 (-1.7) cm long, slightly winged from the decurrent leaf bases, glabrous or glabrescent; blades of minor leaves 2.5-4.5 cm long, 1.5-2.6 cm wide, ovate or elliptic, the major veins 3-4 on each side of mid-vein, the base short-attenuate or rounded and asymmetric, the margins entire, the apex acute or slightly rounded; petioles 0.2-0.5 cm long, glabrescent or moderately pubescent. Inflorescences axillary, 1-3-flowered; flowering pedicels 19-26 mm long, filiform, terete, pendent, slightly curved, non-geniculate at anthesis, usually green, sometimes with purple spots, glabrous or glabrescent, the eglandular trichomes short, antrorse; pedicels scars inconspicuous. Buds ovoid, yellow or pale yellow. Flowers 5-merous. Calyx 1.5-2.6 (-3) mm long, 3-4 mm wide, cup-shaped, thick, purple or greenish-purple, glabrescent to moderately pubescent, the calyx appendages five, (0.9-) 2.5-3 mm long, 0.5-0.8 mm wide, equal, thick, erect, subulate, inserted close to the margin, glabrous or glabrescent with the same trichomes as pedicels and calyx tube. Corolla 14.5-17 mm long, 12-17 mm in diameter, thick, entirely yellow outside and within, tubular-campanulate with interpetalar membrane, lobed less than 1/3 of the way to the base, glabrous adaxially and abaxially, the tube 11-12 mm long, ca. 6 mm in diameter, the lobes 3.5-5 mm long, 4.5-5 mm wide, broadly ovate, erect, the margins finely ciliate, the tips papillate. Stamens five, subequal; filaments 3-5 mm long, greenish-white, inserted on the corolla 3-4 mm from the base, with auricles fused to the corolla at the point of insertion; anthers 2-2.5 (-2.8) mm long, ellipsoid, yellowish-white, slightly connivent at anthesis. Gynoecium with ovary 1.25-1.5 mm long, 1.5 mm in diameter, white, subglobose; ovules more than two per locule; nectary ca. 0.5 mm tall; styles homomorphic, 7.5-8 mm long, barely exserted beyond the anthers, white, clavate; stigma 0.5 mm long, 0.8-1 mm wide, somewhat bilobed, green. Berry 9-12 mm in diameter, globose, slightly flattened at the apex, green or white when immature, orange to red at maturity, non-pungent, the pericarp thick, opaque, lacking giant cells (endocarp smooth); stone cells two, polyhedral, yellowish-white; fruiting pedicels 28-36 mm long, pendent, slightly angled, widened distally, green; fruiting calyx ca. 4 mm in diameter, persistent, not accrescent, discoid, green-purple or green, the appendages 5-6.1 mm long, 0.8-1 mm wide at base, reflexed. Seeds ca. 50-80 per fruit, ca. 2.5 mm long, 2-2.2 mm wide, subglobose or teardrop-shaped, dark brown to black, the seed coat reticulate (SM), reticulate-cerebelloid (SEM), the cells polygonal or irregular in shape, the lateral walls straight or slightly sinuate; embryo imbricate.

Distribution.

Capsicum piuranum is endemic to a restricted area in northern Peru (Piura Department) (Fig. 100 ).

Ecology.

Capsicum piuranum grows in misty rain montane forests, in margins or near streams, between 2,300 and 2,860 m elevation.

Phenology.

Flowering from November to May, with a peak of fruiting in March-May.

Chromosome number.

2 n = 2x = 26 ( Barboza et al. 2019).

Common names.

None recorded.

Uses.

None recorded.

Preliminary conservation assessment.

EOO (10.195 km2); AOO (8 km2). Capsicum piuranum has a very restricted distribution (EOO and AOO) and a small population size (<250 individuals). This species is proposed as Critically Endangered (CR; C2a(i)) because of the inferred continuing decline in the number of mature individuals in each subpopulation (<50).

Discussion.

Capsicum piuranum belongs to the Andean clade ( Barboza et al. 2019). It is morphologically most similar to C. caballeroi of the Bolivian yungas (Santa Cruz and Cochabamba Departments), based on their campanulate yellow corollas, but they can be easily distinguished. Capsicum piuranum has a purple or greenish-purple calyx with five equal subulate appendages, corolla lobes spreading, smaller fruits (up to 12 mm in diameter), orange to red and non-pungent, pericarp with two stone cells and dark brown to black smaller seeds (Fig. 102D-H ). In contrast, C. caballeroi has a green calyx with 10 unequal linear appendages, corolla lobes recurved, larger fruits (up to 16 mm), bright red and pungent, stone cells absent and larger seeds pale yellow or nearly white (Fig. 36E-I ). The species are not sympatric.

Capsicum piuranum is sympatric with other two Andean species, C. geminifolium and C. rhomboideum , both of which also have yellow corollas and non-pungent fruits, but a moderate to dense pubescence on stems and leaves. Capsicum geminifolium differs in having longer calyx appendages (3-6.5 mm long) compared to C. piuranum (2.5-3 mm long) and campanulate generally purple spotted yellow corollas (tubular-campanulate and entirely pure yellow in C. piuranum , Fig. 102E ). Capsicum rhomboideum has ovate to rhomboid-ovate leaves, up to 13 axillary flowers, campanulate or campanulate-rotate smaller corollas (5-10 mm long) and smaller (up to 9 mm in diameter) bright red to dark burgundy fruits (Fig. 113 ) in contrast to C. piuranum , in which leaves are elliptic (sometimes the minor leaves are ovate, Fig. 102B ), the flowers are solitary or up to three (Fig. 102E ), the corolla is tubular-campanulate and longer (14.5-17 mm long, Fig. 102E ) and the orange to red fruits are larger (9-12 mm in diameter) (Fig. 102F ).

Specimens examined.

See Suppl. material 4: Appendix 4.

Figures

Figure 36. Capsicum caballeroi A plant B leaf pairs C major leaf D flower bud E flower F flower, in front view G immature fruit H mature fruit I mature fruit, in cross section, showing the seeds A from Barboza et al. 4907 B, C, E, F, H Barboza et al. 3655 D, G, I from Barboza et al. 4908. Photos by G. E. Barboza and S. Leiva Gonzalez.

Figure 100. Distribution of C. pereirae and C. piuranum.

Figure 101. Capsicum piuranum A reproductive branch B flower C calyx D eglandular trichome of the outer surface of the calyx E opened corolla F, G, H anthers, ventral, dorsal and lateral views, respectively I gynoecium J fruit K seed. From G. E. Barboza & S. Leiva Gonzalez 4841. Drawn by S. Leiva Gonzalez. Published in Barboza et al. (2019), reproduced with permission.

Figure 102. Capsicum piuranum A plant B leaves, abaxial surface C Fruiting branch with leaf pair dissimilar in shape and size D flower bud E flower and immature fruit on pendent pedicels F mature fruit G fruit, in cross section, showing placenta and seeds H fruit, in cross section, showing a stone cell at the apex (arrow). From Barboza & Leiva Gonzalez 4841. Photos by S. Leiva Gonzalez and G. E. Barboza. Published in Barboza et al. (2019), reproduced with permission.

Figure 113. Capsicum rhomboideum A plant B main stem with lenticels flower buds C branch showing leaf pair dissimilar in shape and size D reproductive branch E flower bud F flower, in lateral view G flower, seen from behind H, J flower, in front view, showing connivent and not connivent anthers, respectively I node with a pendent flower and pedicels scars K mature fruits A, J from Barboza & Leiva Gonzalez 4854 B, D-F from Leiva Gonzalez 6585 C, G from Barboza et al. 5050 H, I, K from M. Scaldaferro 73. Photos by G. E. Barboza.