Solanaceae Source

A global taxonomic resource for the nightshade family

Solanum neorossii

Citation author: 
Hawkes & Hjert.
Bot. J. Linn. Soc. 86: 414: 1983.
Argentina. Salta: Dept. Santa Victoria, 14.7 km from Santa Victoria on road to La Quiaca, above Rodeopampa, amongst bushes and in shade of boulders in a quebrada crossing the road, 3350 m, 15 Mar 1966, J.G. Hawkes, J.P. Hjerting, & K. Rahn 3878 (holotype, K; isotype, K000440551).
Last edited by: 
Spooner, D.M.
Written by: 
Spooner, D.M. & A. Clausen
Herbs 0.1-0.5 m tall, decumbent to erect. Stems 2-4 mm in diameter at base of plant, green to purple or green and purple mottled, unwinged, subglabrous to sparsely invested with short unbranched and multiple-celled non-glandular hairs; tubers typically borne singly at the end of each stolon.
Sympodial structure: 
Sympodial units tri- to plurifoliate, not geminate.
Leaves odd-pinnate, the blades 5-16 x 3.8-7.2 cm, green to green and purple-tinged, especially in the veins and abaxially, membranous to chartaceous, sparsely pubescent adaxially and abaxially, denser abaxially and along the veins, with hairs like those of the stems; lateral leaflet pairs 0-3, markedly unequal, decreasing greatly in size toward the leaf base, with the terminal leaflet much larger than the laterals; most distal lateral leaflets (when present) 0.4-4.9 x 0.3-2.2 cm, medium to broadly ovate, the apex acute to rounded, the base typically oblique to rounded to cuneate, sessile with petiolules up to ca. 2 mm long; terminal leaflet 4-10.5 x 1.8-7 cm, very broadly ovate to elliptic to obovate to rounded, the apex obtuse to rounded, sometimes acute, the base shallowly cordate to truncate to rounded to cuneate; interjected leaflets 0-2, sessile to short petiolulate, ovate to orbicular; petioles 1.2-3.2 cm, pubescent as the stems. Pseudostipules absent to minute and scale-like or up to 6 mm long, pubescent with hairs like those of the stem.
Inflorescences 5-9 cm, terminal with a subtending axillary bud, generally in distal half of the plant, usually forked, with 3-8 flowers, with all flowers apparently perfect, the axes pubescent to subglabrous with hairs like those of the stem; peduncle 1.5-3.6 cm long; pedicels 10-26 mm long in flower and fruit, spaced 1-10 mm apart, the articulation point quite variable, from slightly below or above the middle to the distal one-quarter.
Flowers homostylous, 5-merous. Calyx 3-6 mm long, the tube 1-2 mm, the lobes 1-5 mm, acute to attenuate, the acumens 1-2 mm long, with hairs like those of the stem. Corolla 1.8-3.5 cm in diameter, pentagonal to rotate, commonly dark violet purple adaxially and abaxially and commonly darker violet on the outer corolla margins, more rarely pale violet or violet with white stripes adaxially and abaxially, the tube 1-2 mm long, the acumens 1-2 mm long, the corolla edges flat, not folded dorsally, glabrous adaxially, minutely puberulent abaxially, especially along the midribs. Stamens with the filaments 1-2 mm long; anthers 3.5-5 mm long, lanceolate, connivent, yellow, poricidal at the tips, the pores lengthening to slits with age. Ovary glabrous; style 8-11 mm x ca. 1 mm, exceeding stamens by 3-4 mm, straight, glabrous; stigma clavate to capitate.
Fruit a globose to slightly ovoid berry, 0.8-1 cm wide, 1-1.2 cm long, green 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: Hawkes et al. 3878 (PTIS) (Hijmans, et al. 2007)


Solanum neorossii occurs in northern Argentina (Provs. Jujuy and Salta), in dry rocky areas along roadsides, among bushes and large tussocks, in the shade of boulders, or on steep grassy slopes, (2530) 3100-3600 (3800) m in elevation.

Flowering and fruiting from January to March.

Solanum neorossii is a member of Solanum sect. Petota Dumort., the tuber-bearing cultivated and wild potatoes. Within sect. Petota, Solanum neorossii is a member of a very diverse clade related to the cultivated potato. 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 neorossii was described on the basis of Hawkes et al. 3878 from Rodeopampa, Argentina but no other specimens were cited. The authors stated that probably this species was much more widespread, extending into the province of Jujuy, Argentina, as well as into Bolivia. Hawkes and Hjerting (1989) included S. neorosii in their treatment of the Bolivian potatoes, as they indicate that it occurs so near the Bolivian border that it may occur there, but we have not found any Bolivian collections. Hawkes and Hjerting (1989) stated that S. neorossii increases in size under cultivation to a much greater extent than other species studied, and produces leaves with four lateral leaflets, a character usually not observed in the wild.

Hoffman 1874, collected near the type locality and annotated by Hawkes as S. neorossii on a herbarium sheet at PTIS, has pale violet flowers (almost white flowers with darker violet below) and not the dark blue color stated in the description of S. neorossii. K.A. Okada collected a number of accessions from the Province of Jujuy and in eastern Salta Province, and initially considered these to be a new species that he referred to as “S. hannemanii”. This name subsequently appeared on these collections in genebank catalogues and in some publications, but was never validly published. Many of these specimens have purple nerves and in some cases purple pubescence, but are similar in habit, leaf and flower morphology to S. neorossii (including the white flowers with darker violet below). Van den Berg and Groendijk-Wilders (2007) provided morphological and AFLP data to support the recognition of S. hannemanii as a new species, but did not include comparative analysis with accessions of S. neorossii, nor did they publish the name in accordance with the Botanical Code, making S. hannemanii a nomen nudum. On the basis of the original description and illustration of S. neorossii and the herbarium material studied we consider S. hannemanii to be a synonym of S. neorossii.

Solanum neorossii has been found growing in the vicinity of S. venturii, S. vernei and S. acaule. A number of specimens present intermediate characters between S. neorosii and S. venturii: corolla pale mauve, leaves with up to 2 or 3 pair of lateral leaflets, and slightly acuminate leaflets. We list these specimens in our database as hybrids between S. venturii and S. neorossii.

Solanum neorosii can be differentiated from S. venturii by the decumbent habit, blue color of the corolla and by the terminal leaflet generally broadly ovate to elliptical with the apex usually obtuse to rounded. From S. vernei it can be differentiated by its larger terminal leaflet in the lowermost leaves and by the absence of the dense pubescence characteristic of S. vernei. It is not morphologically similar to S. acaule.


Hawkes, J.G. & J.P. Hjerting 1969. The potatoes of Argentina, Brazil, Paraguay and Uruguay: a biosystematic study.
Oxford Univ. Press, Oxford, UK.

Hawkes, J.G. & J.P. Hjerting 1989. The potatoes of Bolivia: their breeding value and evolutionary relationships.
Oxford University Press, Oxford.

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.

Van den Berg, R.G. & N. Groendijk-Wilders 2007. AFLP data support the recognition of a new tuber-bearing Solanum species but are uninformative about its taxonomic relationships.
Pl. Syst. Evol. 269: 133–143.

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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