2n = 2x = 24 voucher: Ochoa & Salas 15565 (US) (Hijmans, et al. 2007)
Western Bolivia (Dept. La Paz), south to northern Argentina (Provs. Catamarca, Jujuy and Salta), in generally dry rocky areas in the open or among spiny shrubs or cacti, along streamsides, or a weed at the edges of cultivated fields or roadsides, (1200) 1600-2100 (3950) m.
Solanum berthaultii 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).
Hawkes (1963) and Hawkes & Hjerting (1989) treated S. berthaultii as a hybrid species between S. tarijense and "a blue-flowered mountain species, possibly S. sparsipilum." Hawkes & Hjerting (1989) subsequently reversed their opinion regarding the hybrid origin of S. berthaultii, but continued to hypothesize extensive hybridization between S. berthaultii and S. tarijense. Fifteen percent of the S. berthaultii and S. tarijense accessions listed in Hanneman & Bamberg (1986) and 24% of the specimens cited in Hawkes & Hjerting (1989) are listed as natural interspecific S. berthaultii x S. tarijense hybrids. Further mention of these here will be "hybrids" for simplicity.
Until 2007 (Spooner et al., 2007) Solanum berthaultii and S. tarijense were recognized as distinct species, since their original description by Hawkes in 1944. A morphological study of Spooner & van den Berg (1992) questioned the validity of separate species status for S. berthaultii and S. tarijense. Multivariate analyses of morphological data failed to support separate species, showing great overlap of three “species-specific” characters used to separate the species (presence/absence Type B trichomes [long-stalked glandular trichomes], corolla color, corolla shape), and a geographic analysis of these characters showed them to be distributed throughout the range of both species. For example, intra-accession variability for presence/absence of Type B trichomes was encountered in eight of the 64 accessions examined. Corolla colors varied continuously from pure white to dark-blue, and plants from only one geographic area in the extreme south of Salta Province had all corollas pure white (a S. tarijense character, but most of these accessions possessed Type B trichomes, a S. berthaultii character). Corolla colors and shapes exhibited no statistically significant differences between any of the taxa.
Hawkes & Hjerting (1989) designated K as the deposition of the holotype of S. berthaultii, but we did not find a sheet designated as holotype despite our extensive searches there.
The locality of Solanum vallegrandense is a correction provided in Hawkes & Hjerting, 1989: 144, 258, by pers. comm. from M. Cárdenas, of erroneous locality data originally reported on specimens and in the protologue, reported as “on way from Trigal to Mataral, 2000 m.”
Many collections of Hawkes and his collaborators were deposited at the Commonwealth Potato Collection (CPC) herbarium in Dundee Scotland, and Correll took many photos of these. All of these collections were widely distributed to other herbaria but we were not able to locate all of the specimens that match the photos.
Hawkes, J.G. 1963. A revision of the tuber-bearing Solanums. II.
Scott. Pl. Breed. Sta. Rec. 1963: 76-181.
Hawkes, J.G. & J.P. Hjerting 1969. The potatoes of Argentina, Brazil, Paraguay and Uruguay: a biosystematic study.
Oxford Univ. Press, Oxford, UK.
Hanneman, R.E. & J.B. Bamberg 1986. Inventory of the tuber-bearing Solanum species.
Wisconsin Agric Exp. Sta. Bull. 533: 1-216.
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.
Spooner, D.M. & R.G. van den Berg 1992. Species limits and hypotheses of hybridization of Solanum berthaultii Hawkes and S. tarijense Hawkes: morphological data.
Taxon 41: 685-700.
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.
Spooner, D.M., D. Fajardo, & G.J. Bryan 2007. Species limits of Solanum berthaultii Hawkes and S. tarijense Hawkes and the implications for species boundaries in Solanum sect. Petota.
Taxon 56: 987-999.
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.