2n = 2x = 24 voucher: Ochoa & Salas 15506 (CUZ, NY) (Hijmans, et al. 2007)
Solanum okadae is endemic to Bolivia (Depts. La Paz, Cochabamba, Chuquisaca), growing in sunny fields, cultivated fields, among bushes, or in shade of trees, in rocky soils of rich soils; 2450-3200 m in elevation.
Solanum okadae is a member of Solanum sect. Petota Dumort., the tuber-bearing cultivated and wild potatoes. Within sect. Petota, Solanum okadae 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).
Hawkes, J.G. & J.P. Hjerting 1983. New tuber-bearing Solanum taxa from Bolivia and northern Argentina.
Bot. J. Linn. Soc. 86: 405-417.
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.
Clausen A.M. & V.N. Ispazúa 2005. Caracterización morfológica de Solanum okadae.
XXX Jornadas Argentinas de Botánica, Rosario, Córdoba, Argentina. Actas en el Boletín de la Sociedad Argentina de Botánica. 40: 59.
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.
Hawkes and Hjerting (1983) described S. okadae on the basis of specimens from Bolivia, (Depts. Cochabamba and La Paz) and from Argentina (Provs. Jujuy and Salta), they failed to cite collections from Argentina. Hawkes and Hjerting (1989) stated that that they originally thought that S. okadae was vigorous and tall, although in its natural habitat it formed small tufts or semi-rosettes with simple leaves or leaves with only one set of lateral leaflets. Hawkes (1990) stated that S. okadae, S. venturii and S. microdontum were closely related species, but S. venturii could be distinguished from S. okadae by the larger terminal and smaller lateral leaflets.
Ochoa (1990), when comparing S. venturii and S. microdontum, stated that S. venturii is taller, more vigorous, larger-flowered and more pubescent than S. microdontum, and stated that the true affinity of S. microdontum is with S. okadae because both present a large terminal leaflet of similar shape, and have sparsely pilose and poorly dissected leaves.
Clausen and Ispizúa (2005), when comparing the disjunct populations of S. okadae from Bolivia and from Argentina found that the Bolivian accessions of S. okadae could be differentiated from the Argentinean populations on the bases of larger leaves, larger peduncle, larger calyx, winged stem, and more pairs of lateral leaflets. We identify the Argentinean populations thought to be S. okadae as S. venturii and the Bolivian populations as S. okadae.
Van den Berg and Groendijk-Wilders (2007), included a few populations of S. okadae and S. venturii from Argentina and S. okadae from Bolivia in a wider morphological and AFLP study. Their morphological analysis was not consistent, but their AFLP study showed that the Argentinean populations of S. okadae and S. venturii clustered together while S. okadae from Bolivia formed a distinct group. Solanum okadae can be identified by its white rotate to rotate pentagonal corollas, Leaves sparsely pubescent, generally smaller than S. microdontum, 2-4 mm wide at base, and plants 20-80 cm tall; leaves 7-14 cm wide; in contrast to plants 18-25 cm tall; leaves 4.8-7 mm wide; as in S. venturii.