Solanaceae Source

A global taxonomic resource for the nightshade family

Solanum chomatophilum

Citation author: 
Bitter
Citation: 
Abh. Naturwiss. Vereine Bremen 25: 246. 1924.
Type: 
Peru. Ancash: Prov. Pallasca, below the mines of Huaura, 3900 m, Weberbauer 7201 (holotype, B, destroyed [F neg. 2601, F, G, GH, MO, NY]; lectotype, US1473472, designated by Ochoa, 1999 [Correll neg. 764, BM000881732, F-1603117, GH, LL, NY, UC1152234]; isolectotypes, F-549077 [Correll neg. 260, BM000881734, F-1604021, GH, LL, MO, NY, PTIS, UC1152234], F [Correll neg. 765, BM000881731, F 1603116, LL, UC 1152234], G-877066, GH00057137 [Correll neg. 261, BM000881733, F-1604022, GH, LL, NY, UC1152234]).
Last edited by: 
Spooner, D.M.
Written by: 
Spooner, D.M. & M. Ames
Habit: 
Herbs 0.1-0.9 m tall, erect. Stems 0.5-7 mm in diameter at base of plant, usually unwinged, completely glabrous to glabrescent; 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 4.9-23.5 x 2.8-10.3 cm, light to deep green throughout, sometimes with some light purple coloration to completely purple abaxially, usually glabrous to glabrescent with white short hairs adaxially, glabrous to glabrescent with short hairs abaxially; lateral leaflet pairs 2-7, usually decreasing in size toward the leaf base, sometimes the most distal pair of lateral leaflets slightly smaller than the second most distal pair; with the terminal leaflet generally subequal to the laterals or slightly larger; most distal lateral leaflets 1.5-5.9 x 0.5-3.4 cm, ovate to elliptic, the apex acute to acuminate, the base petiolulate or sessile and attenuate to rounded, asymmetric with more tissue on the basiscopic side; terminal leaflet 1.7-8 x 0.8-4.2 cm, ovate to elliptic, the apex acute to acuminate, the base usually attenuate; interjected leaflets 0-36, sessile to short petiolulate, ovate to orbicular; petioles 0.3-2.3 cm, glabrous to glabrescent. Pseudostipules when present 1-8 mm long, usually glabrous.
Inflorescences: 
Inflorescences 4-18.5 cm, terminal with a subtending axillary bud, generally in distal half of the plant, usually forked, with 2-38 flowers, with all flowers apparently perfect, the axes glabrous or subglabrous with short white hairs; peduncle 0.4-12.8 cm long; pedicels 10-80 mm long in flower and fruit, spaced 3-5 mm apart, articulated high in the distal half.
Flowers: 
Flowers homostylous, 5-merous. Calyx 4-18 mm long, the tube 1-3 mm, the lobes 3-10 mm, ovate to lanceolate, with acumens 0.5-5 mm long, glabrous to glabrescent with white short hairs. Corolla 1.8-5.2 cm in diameter, pentagonal to rotate, lilac to blue, the tube 1-2 mm long, the acumens 0.8-3 mm long, the corolla edges flat, not folded dorsally, glabrous to glabrescent with white short hairs abaxially and adaxially. Stamens with the filaments 1-2 mm long; anthers 3-10 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 0-7 mm, straight, glabrous; stigma clavate to capitate.
Fruits: 
Fruits variable in shape, globose, ovoid to elliptic, 1-3.4 cm long and 0.9-3.1 cm wide light, medium to deep green, sometimes with deep green or purple stripes 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 13199 (CIP) (Hijmans, et al. 2007)

Distribution: 

Ecuador (Provs. Azuay and Pichincha), north and central Peru (Depts. Amazonas, Ancash, Cajamarca, Huánuco, La Libertad, Lima, Junín, Pasco and San Martín). Solanum chomatophilum is found in a wide diversity of habitats: along streamsides, on rocky or eroded slopes, poor soils or rich organic soils, on wet shrubby habitats, or in the sub-paramos, punas and grasslands, among herbs, shrubs or trees; 1950-4800 m in elevation, with the majority of the populations growing between 3200-4000 m.

Phenology: 
Flowering and fruiting mostly from March to June; however there are some records from collections in flower during all months of the year.
Phylogeny: 

Solanum chomatophilum is a member of Solanum sect. Petota Dumort., the tuber-bearing cultivated and wild potatoes. Within sect. Petota, Solanum chomatophilum 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, although this species sometimes has pubescent 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 chomatophilum (with lilac to blue corollas) is morphologically similar to S. albornozii and S. augustii, but the latter two species have white corollas. Solanum chomatophilum is a morphologically very variable species, making it difficult to distinguish from these two taxa by other characters.

Ochoa deposited many of his types in “herb. OCH” or “herb. Ochoa,” his personal herbarium. He recently distributed many of these types to various herbaria but there is no published record of these distributions. We located most of them at CUZ and most of them are labeled as holotype.

Ochoa (1954) did not designate a herbarium for the deposition of the type of S. jalcae Ochoa, and we located seven duplicates. We consider the holotype to be a specimen at CUZ labeled as holotype and matching the illustration in the description.

Ochoa (1999) synonymized Solanum chomatophilum forma pilosum under S. piurae Bitter, and the CUZ isotype is labeled and filed under this name.

References: 

Ochoa, C.M. 1954. Nuevos Solanum (Tuberarium) de la serie Megistacroloba.
Agronomía (Lima) 19(79-80): 166-173.

Ochoa, C.M. 1999. Las papas de sudamerica: Peru (Parte I).
Lima, Peru: International Potato Center.

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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