2n = 3x = 36 voucher: Okada 6154 (BAL) (Hijmans, et al. 2007)
2n = 2x = 24 voucher: Spooner & Clausen 4632 (PTIS) (Hijmans, et al. 2007)
Central Bolivia (Dept. Cochabamba) to northern and western Argentina (Provs. Catamarca, La Rioja, Jujuy, Tucumán and Salta), in narrow humid quebradas, on the banks of streams, under the shade of trees and bushes, at the border of cultivated fields, in dense forests and woods, growing on dead trees or branches, high grassy mountain plains, in forests and woods; (1400) 1600-2900 (3850) m in elevation.
Solanum microdontum 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).
Many populations of S. microdontum are distinguished by simple leaves, but intra- and interpopulational variability encompasses morphotypes with pinnately compound leaves more similar to those of other wild species. This variability has been partitioned into six species, three subspecies, and six varieties, but recent classifications reduced this variability to one species with two subspecies: subspecies microdontum and subspecies gigantophyllum (Hawkes, 1990) or three varieties, variety microdontum, variety metriophyllum Bitter, and variety montepuncoense (Ochoa, 1990). Phenetic analysis of morphological data (Van den Berg and Spooner, 1992) showed these infraspecific taxa to be unwarranted. Variety microdontum and variety metriophyllum are equivalent nomenclaturally to subspecies microdontum and subspecies gigantophyllum, respectively. Variety montepuncoense was distinguished by rotate corollas white tinged with blue and, but is known only from a single locality and otherwise appears to be S. microdontum. Van den Berg and Spooner (1992) synonymized all of these names, except variety montepuncoense which we now synonymize in S. microdontum.
Brücher and Ross (1953) designated four syntypes for S. simplicifolium variety variabile, deposited at GOET. Van den Berg and Spooner (1992) searched GOET unsuccessfully for these specimens, but the original description makes the affiliation of this name clear. The collector designation, EBS, refers to codes of the Erwin Baur Sortiment Genebank in Cologne, Germany. It is possible that these numbers refer to seed collections and no original collections were made in the field or deposited at GOET.
Brücher, H. & H. Ross 1953. Las especies tuberíferas de Solanum del noroeste Argentino.
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Hawkes, J.G. & J.P. Hjerting 1969. The potatoes of Argentina, Brazil, Paraguay and Uruguay: a biosystematic study.
Oxford Univ. Press, Oxford, UK.
Okada, K.A. 1981. High frequency of triploids of Solanum microdontum subsp gigantophyllum on the western mountain ranges of Provinces La Rioja and Catamarca, Argentina.
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Hawkes, J.G. & J.P. Hjerting 1989. The potatoes of Bolivia: their breeding value and evolutionary relationships.
Oxford University Press, Oxford.
Hawkes, J.G. 1990. The potato: evolution, biodiversity and genetic resources.
Oxford: Belhaven Press.
Van den Berg, R.G. & D.M. Spooner 1992. A reexamination of infraspecific taxa of a wild potato, Solanum microdontum Bitter (Solanum sect. Petota: Solanaceae).
Pl. Syst. Evol. 182:239-252.
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.