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.
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.