Solanaceae Source

A global taxonomic resource for the nightshade family

Solanum scabrifolium

Citation author: 
Ochoa
Citation: 
Darwiniana 17: 427. 1972.
Type: 
Peru. Huánuco: Prov. Huamalíes, vicinities of Pincullo, 2940 m, 22 Apr 1967, C. Ochoa 2633 (holotype, CUZ).
Last edited by: 
Spooner, D.M.
Written by: 
Spooner, D.M. & M. Ames
Habit: 
Herbs 0.2-0.8 m tall, erect. Stems 2-8 mm in diameter at base of plant, purple to purple and green mottled, narrowly winged, 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: 
Leaves odd-pinnate, the blades 7-16.5 x 5-9.4 cm, medium green adaxially, green with some purple color abaxially, coriaceous, glabrous adaxially and abaxially; lateral leaflet pairs 2-5, decreasing in size toward the leaf base, with the terminal leaflet subequal to the laterals; most distal lateral leaflets 5.7-8.8 x 1.5-2.2 cm, ovate to elliptic, the apex acute to round, the base typically sessile to short petiolulate, usually asymmetric with more tissue on the basiscopic side; terminal leaflet 3.8-5.4 x 1.5-2.2 cm, ovate to elliptic, the apex acute, the base attenuate; interjected leaflets 0-10, usually sessile, ovate to orbicular; petioles 1-2 cm, glabrous. Pseudostipules 6-8 mm long, glabrous.
Inflorescences: 
Inflorescences terminal with a subtending axillary bud, generally in distal half of the plant, usually forked, with 4-25 flowers, with all flowers apparently perfect, the axes glabrous; peduncle 2.1-3 cm long; pedicels 8-28 mm long in flower and fruit, spaced 3-5 mm apart, articulated slightly above the middle.
Flowers: 
Flowers homostylous, 5-merous. Calyx 7-8 mm long, the tube 1-3 mm, the lobes 3-6 mm, usually ovate to lanceolate, with ovate acumens 0.4-2 mm long, glabrous. Corolla 2.4-3.4 cm in diameter, pentagonal to rotate, lilac to blue with a white star, 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 4-6 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 1-7 mm, straight, glabrous; stigma clavate to capitate.
Fruits: 
Fruit a globose berry, 1-1.5 cm in diameter, medium to deep green with dark green or purple spots when ripe, glabrous.
Seeds: 
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 & Salas 60 (CIP) (Hijmans, et al. 2007)

Distribution: 

Solanum scabrifolium is endemic to central Peru (Dept. Huánuco), on rocky slopes among bushes, 2800-3340 m in elevation.

Phenology: 
Flowering and fruiting around March and April.
Phylogeny: 

Solanum scabrifolium is a member of Solanum sect. Petota Dumort., the tuber-bearing cultivated and wild potatoes. Within sect. Petota, Solanum scabrifolium 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).

Commentary: 

Solanum scabrifolium is morphologically similar to S. cantense. Both species possess terminal leaflets subequal to the lateral leaflets and are glabrous adaxially. However, S. scabrifolium has leaflets acute to rounded at the tips and purple corollas with a white central star whereas S. cantense has leaflets acuminate at the tips and white corollas throughout.

References: 

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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