Solanaceae Source

A global taxonomic resource for the nightshade family

Solanum acroscopicum

Citation author: 
Ochoa
Citation: 
Agronomía (Lima) 18: 130. 1953.
Type: 
Peru. Tacna: Prov. Tarata, Chivatería, near Tarata, 3450 m, C. Ochoa 2043 (holotype, CUZ; isotypes, GH [photo from unknown source, GH; Correll neg. 70, BM000881796, MOL, NY, UC-1152159], US00027437 [Correll neg. 423, BM000881795, NY, UC-1152159]).
Last edited by: 
Spooner, D.M.
Written by: 
Spooner, D.M. & M. Ames
Habit: 
Herbs 0.30-2.0 m tall, erect. Stems 5-20 mm in diameter at base of plant, unwinged or narrowly winged, glabrous, light green or with purple dots in the basal part.
Sympodial structure: 
Sympodial units tri- to plurifoliate, not geminate.
Leaves: 
Leaves odd-pinnate, the blades 9-31 x 5.5-18 cm, medium green abaxially and adaxially, chartaceous, glabrous to glabrescent with very short white hairs adaxially, glabrous abaxially; lateral leaflet pairs 4-5, not or just slightly decreasing in size toward the leaf base except for the most proximal lateral leaflet whose size decreases considerably, with the terminal leaflet generally subequal or slightly larger to the laterals; most distal lateral leaflets 3.7-8.6 x 1.1-2.3 cm, ovate to elliptic, the apex acute to acuminate, the base typically petiolulate and attenuate to rounded, sometimes asymmetric with more tissue on the basiscopic side; terminal leaflet 3.5-10.5 x 0.7-2.7 cm, ovate to elliptic, the apex acute to acuminate, the base attenuate; interjected leaflets 0-16, sessile to short petiolulate, ovate to orbicular; petioles 0.8-2.6 cm, glabrous. Pseudostipules 5-15 mm long, glabrous to subglabrous.
Inflorescences: 
Inflorescences 5.3-17.5 cm, terminal and lateral with a subtending axillary bud, generally in distal half of the plant, usually forked, with 10-40 flowers, with all flowers apparently perfect, the axes glabrous; peduncle 2-12 cm long; pedicels 15-40 mm long in flower and fruit, articulated high in the distal half.
Flowers: 
Flowers homostylous, 5-merous. Calyx 3-8 mm long, the tube 1-3 mm, the lobes 2-7 mm, ovate to apiculate, with linear acumens 2-7 mm long, glabrous. Corolla 2.5-4 cm in diameter, pentagonal to rotate-pentagonal, lilac to purple, the tube 1-2 mm long, the acumens 0.8-4 mm long, the corolla edges flat, not folded dorsally, glabrous abaxially and adaxially but with short white hairs on the corolla acumens . Stamens with the filaments 0.5-2 mm long; anthers 5.5-8 mm long, lanceolate, connivent, yellow, poricidal at the tips, the pores lengthening to slits with age. Ovary glabrous; style 10.5-12 mm x ca. 1 mm, exceeding stamens by 3-4 mm, straight, glabrous; stigma clavate to capitate.
Fruits: 
Fruit a globose berry, 1.5-2 cm in diameter, green, sometimes with white dots 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 86 (CIP) (Hijmans, et al. 2007)

Distribution: 

Peru (Depts. Arequipa, Ayacucho, Cajamarca and Tacna), on rocky cracks and humid places and in the shade, in rich soils, among herbs or shrubs, 2350-3900 m in elevation.

Phenology: 
Flowering and fruiting from February to June.
Phylogeny: 

Solanum acroscopicum is a member of Solanum sect. Petota Dumort., the tuber-bearing cultivated and wild potatoes. 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 acroscopicum is morphologically similar to S. trinitense but they mainly differ by the color of the corollas. Solanum acroscopicum has lilac to purple corollas and S. trinitense white corollas.

References: 

Correll, D.S. 1962. The potato and its wild relatives.
Contr. Texas Res. Found., Bot. Stud. 4: 1-606.

Ochoa, C.M. 1999. Las papas de Sudamerica: Perú.
Centro International de La Papa (CIP), Lima, Perú.

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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