2n = 2x = 24 voucher: Spooner & Clausen 7224 (CIP, MOL, PTIS, WAG) (Hijmans, et al. 2007)
Solanum lignicaule is endemic to Peru (Dept. Cuzco), among bushes or cacti, among loose stones, on rocky slopes, often in dry environments, in sandy or rocky soil; 2510-3460 m in elevation.
Solanum lignicaule is a member of Solanum sect. Petota Dumort., the tuber-bearing cultivated and wild potatoes. Within sect. Petota, S. lignicaule is a member of a very diverse clade related to the cultivated potato. Hawkes (1990) and Ochoa (1999) place S. lignicaule as the sole representative of series Lignicaulia, but its distinctive series status is not supported by plastid DNA restriction site data (Spooner and Castillo, 1997) or AFLP data (Jacobs et al., 2008). On a higher taxonomic level, S. lignicaule 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 lignicaule is one of the most distinctive species in sect. Petota, with its combination of white corollas, relatively narrow terminal and lateral leaflets, and leaves that are densely short canescent beneath. The woody habit mentioned for this species is not clearly distinctive as some other species also are firm at the base and may also be woody. There is no comparative study of members of sect. Petota quantifying woody vs. herbaceous stems.
Hawkes, J.G. 1990. The potato: evolution, biodiversity and genetic resources.
Oxford: Belhaven Press.
Spooner, D.M. & R. Castillo-T 1997. Reexamination of series relationships of South American wild potatoes (Solanaceae: Solanum sect. Petota): evidence from chloroplast DNA restriction site variation.
Amer. J. Bot. 84: 671-685.
Ochoa, C.M. 1999. Las papas de sudamerica: Peru (Parte I).
Lima, Peru: International Potato Center.
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.
Jacobs, M.J., R.G. van den Berg, V.G.A.A. Vleeshouwers, M. Visser, R. Mank, M. Sengers, R. Hoekstra & B. Vosman 2008. AFLP analysis reveals lack of phylogenetic structure within Solanum section Petota.
BMC Evol. Biol. 8, 145: 2-12.