2. Elatine Linnaeus, Sp. Pl. 1: 367. 1753; Gen. Pl. ed. 5, 172. 1754.
Waterwort, élatine [Greek name for a plant with firlike leaves] Waterwort, élatine [Greek name for a plant with firlike leaves]
Gordon C. Tucker
Donald H. Les
Herbs, submersed or emergent aquatic, glabrous. Stems erect, ascending, decumbent, or prostrate, with longitudinal air spaces, rooting at nodes. Leaves: stipules membranous; petiole present or absent; blade margins entire, with hydathodes. Inflorescences: flowers usually solitary, sometimes 2[–3] per node. Pedicels present or absent. Flowers: sepals 2–4, connate basally, equal or 1 smaller, not carinate, apex obtuse; petals (0 or) 2–4, apex obtuse; stamens [0–]1–8; pistil 2–4-carpellate, ovary 2–4-locular, apex truncate; styles 2–4; stigmas 2–4. Capsules membranous. Seeds 2–33[–44] per locule, brown to yellowish brown, straight or curved (nearly circular in E. californica), surface with hexagonal, rectangular, elliptic, or ± round pits (pits oriented with longer dimension at right angles to length of seed). x = 9.
Species ca. 25 (10 in the flora): North America, Mexico, South America, Europe, Asia, Africa, Pacific Islands, Australia.
SELECTED REFERENCES Duncan, W. H. 1964. New Elatine populations in the southeastern United States. Rhodora 66: 47–53. Fassett, N. C. 1939. Notes from the herbarium of the University of Wisconsin. No. 17. Elatine and other aquatics. Rhodora 41: 367–377. Fernald, M. L. 1917. The genus Elatine in eastern North America. Rhodora 19: 10–15. Fernald, M. L. 1941b. Elatine americana and E. triandra. Rhodora 43: 208–211.