In forest and second growth in Nicaragua, W Costa Rica, and adjacent Panama, from sea level to 200 m.
Solanum valerianum is a member of the Solanum confine species group (Knapp, 2002) of the Geminata clade (Bohs, 2005).
Solanum valerianum is related to S. capillipes of Trinidad and Venezuela. Solanum valerianum differs from S. capillipes in its denser, longer stem pubescence, smaller inflorescences, and in its leaf venation. The main lateral veins of S. valerianum do not prominently converge on one other (ie: not markedly brochidodromous sensu Hickey, 1974) as do those of S. capillipes. The type specimen of S. valerianum is in very poor condition, with only one damaged flower on the collection. Collections from the Carara region in western Costa Rica have shorter trichomes than the type.
Knapp, S. 2002. Solanum section Geminata (G. Don) Walpers (Solanaceae).
Flora Neotropica 84: 1-405.
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.