On the W margin of the Amazon basin in Colombia, Ecuador and Perú, in tropical wet forest, from 200-1300 m.
Solanum malletii is a member of the Solanum nutans species group (Knapp, 2002) of the Geminata clade (Bohs, 2005).
Solanum malletii can easily be distinguished from other members of the S. nutans species group by its orbicular minor leaves and auriculate major leaf bases. The elongate, densely pubescent inflorescences of this species are like those of S. youngii, but S. malletii is easily distinguished from that species by its non-bullate leaves, orbicular minor leaves, and low elevation habitat.
The prescence of short-styled flowers in S. malletii (see Fig. 74B in Knapp, 2002) indicates that it is probably andromonoecious, but this has yet to be tested in the field.
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.