Bacopa rotundifolia
in H. G. A. Engler and K. Prantl, Nat. Pflanzenfam. 67[IV,3b]: 76. 1891.
Common names: Round leaf water-hyssop
WeedyIllustratedEndemic
Basionym: Monniera rotundifolia Michaux Fl. Bor.-Amer. 2: 22. 1803
Synonyms: Bacopa nobsiana H. Mason B. simulans Fernald Bramia rotundifolia (Michaux) Britton Macuillamia rotundifolia (Michaux) Rafinesque
Annuals [perennials]. Stems prostrate, 15–60 cm, hairy, sometimes sparsely so, glabrescent. Leaves hairy; blade base broadly cuneate, margins entire, apex ± rounded. Pedicels 9–15 mm. Flowers: sepals 5, ovate to oblong, calyx bilaterally symmetric; corolla white with yellow throat, 5–10 mm; stamens 2–4, equal. 2n = 56.
Phenology: Flowering May–Nov.
Habitat: In water or on mud in lakes, ponds, pools, in and around marshes and ditches, ephemeral pools on rock outcrops.
Elevation: 0–2300 m.
Distribution
Alta., Sask., Ala., Ariz., Ark., Calif., Colo., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Md., Minn., Miss., Mo., Mont., Nebr., N.Mex., N.C., N.Dak., Okla., S.Dak., Tenn., Tex., Va., Wis., Wyo., introduced in Europe (Greece, Spain).
Discussion
Bacopa rotundifolia is the most widespread member of the genus in the United States; it is invasive in rice fields.
Selected References
None.
Lower Taxa
None.