Ludwigia linearis Walter var. linearis . Section: Isnardia. Phen: Jun-Sep. Hab: Pine savannas, swamps, marshes. Dist: Var. linearis ranges from s. NJ south to c. peninsular FL, west to se. LA, extending inland to the Cumberland Plateau of nc. AL and c. TN.
Origin/Endemic status: Endemic
Taxonomy Comments: Var. linearis is here interpreted to be equivalent to Peng's subglabrous morph. Peng (1989) declined to recognize infraspecific taxa in L. linearis, but his discussion makes clear that two distinctive entities are present, as characterized by orientation of seed surface cells and characters of leaves, bracteoles, pedicels, sepals, stigmas, and styles (see key). The orientation of seed surface cells, recognized as a distinctive character in other difficult species pairs (such as L. alata and L. lanceolata) is the most reliable character separating the 2 varieties. This species is diploid (n = 8).
Synonymy: < Ludwigia linearis Walter – C, F, Fl4, FNA10, G, GW2, K1, K3, K4, RAB, S, Tn, Va, W, WH3, Peng (1989), Wagner, Hoch, & Raven (2007)