Solanum tampicense Dunal
Common names: wetland nightshade, aquatic soda apple
Fruit a berry with 10–60 seeds. Seeds ovate to C- or D-shaped in outline, variously bent or twisted from crowding, usually with a prominent V-shaped notch; 2–2.5 mm long, 1.5–2.2 mm wide, 0.3–0.7 mm thick, compressed, discoid, cross section linear, straight or bent. Testa +/– light yellow, glistening and reticulate overall, or only on border with central area dull and depressed. Reticulations thick walled, +/– wavy, with deep interspaces. Hilum marginal, pointing straight out from notch, a closed linear slit, sometimes partly or fully open, 0.6–1 mm long. Embryo linear-curved, seen twice in cross section; endosperm readily visible.
Solanaceae seeds of moderate size (over 1.5 mm long) are often difficult to distinguish from one another. Characters that may aid in identification are size range, seed outline, surface reticulation (if visible), hilar shape, and embryo shape. Testa color is not a reliable character, as it may be affected by aging and length of time spent in a mature berry.
Lycium ferocissimum Miers
Solanum torvum Sw.
Solanum viarum Dunal
Mexico, Central America (Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua), Cuba, United States.
Relatively undisturbed tropical wetlands, cypress swamps, river and stream margins, river drainages; does not tolerate continuous flooding.
Solanum tampicense is a vinelike, sprawling, prickly shrub with stems up to 5 m long. It may have been accidentally introduced to Florida fairly recently, where it disrupts natural wetland habitats. It grows as impenetrable thickets and can form large stands of many acres. Solanum tampicense can regenerate from stem sections, and its seeds can tolerate freezing and drying.