Solanaceae Source

A global taxonomic resource for the nightshade family

Solanum piurae

Citation author: 
Bot. Jahrb. Syst. 54, Beibl. 119: 5. 1916.
Peru. Piura: Prov. Ayabaca, above Ayabaca, near 04°40’S, 2800 m, May 1912, A. Weberbauer 6370 (holotype, B, destroyed, [F neg. 2630, F-647967 (photo and fragment), G-8770179, MO-1691347, NY]).
Last edited by: 
Spooner, D.M.
Written by: 
Spooner, D.M. & M. Ames
Herbs 0.15-0.8 m tall, erect. Stems 2-8 mm in diameter at base of plant, purple, usually unwinged but sometimes with a narrow wing up to 1 mm, glabrous; tubers typically moniliform (multiple tubers arranged along the stolon like beads on a necklace).
Sympodial structure: 
Sympodial units tri- to plurifoliate, not geminate.
Leaves odd-pinnate, the blades 9.4-20.1 x 6.1-12.8 cm, dark green adaxially, light green abaxially, coriaceous, glabrous adaxially and abaxially with ciliate margins that are rough to the touch; lateral leaflet pairs 1-5, decreasing in size toward the leaf base, with the terminal leaflet sometimes larger than the laterals but in general subequal to the laterals; most distal lateral leaflets 3.7-6.8 x 1.1-2.7 cm, ovate to elliptic, the apex acute to acuminate, the base typically petiolulate and attenuate to rounded, usually symmetric but sometimes asymmetric with more tissue on the basiscopic side; terminal leaflet 5.3-9 x 2.3-3.6 cm, ovate to elliptic, the apex acute to acuminate, the base attenuate; interjected leaflets 0-24, sessile or shortly petiolulate, ovate to orbicular; petioles 0.8-2 cm, glabrous. Pseudostipules 4-17 mm long, glabrous.
Inflorescences 7.1-17.5 cm, terminal with a subtending axillary bud, generally in distal half of the plant, usually forked, with 4-39 flowers, with all flowers apparently perfect, the axes glabrous; peduncle 1-10 cm long; pedicels 11-45 mm long in flower and fruit, spaced 3-5 mm apart, articulated high in the distal half.
Flowers homostylous, 5-merous. Calyx 3-5 mm long, the tube 1-4 mm, the lobes 1-2 mm, usually ovate to lanceolate, with linear acumens 1-2 mm long, glabrous. Corolla 2.4-3.8 cm in diameter, pentagonal to rotate, lilac to blue, the tube 1-2 mm long, the acumens 2-3 mm long, the corolla edges flat, not folded dorsally, glabrous adaxially and abaxially. Stamens with the filaments 1-2 mm long; anthers 4-7 mm long, lanceolate, connivent, yellow, poricidal at the tips, the pores lengthening to slits with age. Ovary glabrous; style 3-10 mm x ca. 1 mm, exceeding stamens by 2-6 mm, straight, glabrous; stigma clavate to capitate.
Fruit an ovoid berry, 1.2-1.8 cm wide, 1-2 mm wide, medium to deep green, sometimes with white dots when ripe, glabrous.
Seeds from living specimens ovoid and ca. 2 mm long, whitish to greenish in fresh condition and drying brownish, with a thick covering of “hair-like” lateral walls of the testal cells that make the seeds mucilaginous when wet, green-white throughout; testal cells honeycomb-shaped when lateral walls removed by enzyme digestion.
Chromosome number: 

2n = 2x = 24 voucher: Ochoa 13959 (CIP) (Hijmans, et al. 2007)


Solanum piurae is endemic to northern Peru (Dept. Piura), among bushes and rocks but also in humid soils, 2000-3360 m in elevation.

Flowering and fruiting from April to June.

Solanum piurae is a member of Solanum sect. Petota Dumort., the tuber-bearing cultivated and wild potatoes. Within sect. Petota, Solanum piurae is a member of a distinctive clade of southern Ecuadorian and Peruvian species formerly classified in series Piurana and some other series that frequently possess moniliform tubers and shiny coriaceous leaves. On a higher taxonomic level, it is a member of the informally-named Potato Clade, a group of perhaps 200-300 species that also includes the tomato and its wild relatives (Bohs, 2005).


Solanum piurae is morphologically similar to S. acroglossum and to some populations of S. chomatophilum. These species are similar because their stems have leaves glabrous adaxially and lilac to blue corollas. Solanum piurae has petiolulate lateral leaflets whereas S. acroglossum has sessile lateral leaflets; S. chomatophilum has lateral leaflets varying from sessile to petiolulate.


Bohs, L. 2005. Major clades in Solanum based on ndhF sequences.
Pp. 27-49 in R. C. Keating, V. C. Hollowell, & T. B. Croat (eds.), A festschrift for William G. D’Arcy: the legacy of a taxonomist. Monographs in Systematic Botany from the Missouri Botanical Garden, Vol. 104. Missouri Botanical Garden Press, St. Louis.

Hijmans, R., T. Gavrilenko, S. Stephenson, J. Bamberg, A. Salas & D.M. Spooner 2007. Geographic and environmental range expansion through polyploidy in wild potatoes (Solanum section Petota).
Global Ecol. Biogeogr. 16: 485-495.

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