This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Fleshy decumbent or prostrate herbs, with opposite leaves and solitary or clustered axillary pink or purplish flowers. Stipules none, but the petioles often dilated and connate at the base. Calyx top-shaped, 5-lobed, the lobes oblong, ovate or lanceolate. Petals none. Stamens 5-60, inserted on the tube of the calyx. Filaments filiform, sometimes united at the base. Ovary 3-5-celled. Styles 3-5, papillose along the inner side. Capsule membranous, oblong, 3-5-celled, circumscissile. Seeds round-reniform, smooth; embryo annular.
About 4 species, natives of sea-coasts and saline regions. Besides the following, another, S. Portulacastrum L., the generic type, occurs in the Southern States.
Stamens 5; coastal species.
Stamens numerous; inland species.
Pharnaceum maritimum Walt. Fl. Car. 117.
1788. Sesuvium pentandrum Ell. Bot. S. C. & Ga.
1: 556. 1821. Sesuvium maritimum B.S.P. Prel. Cat. N. Y.
Annual, glabrous, decumbent or ascending, rarely erect, branches 2'-12' long. Leaves obovate or spatulate, entire, rounded or slightly emarginate at the apex, narrowed into a petiole or the upper ones sessile, 4"-12" long; flowers sessile or very nearly so, about 2" broad, mostly solitary in the axils; stamens 5, alternate with the calyx-lobes; capsule ovoid, about 2" high, scarcely longer than the calyx.
Sesuvium sessile Pers. Syn. 2: 39. 1807.
Annual, glabrous, fleshy, usually much branched, the branches erect or ascending, 4'-16' long. Leaves oblanceo-late to obovate, obtuse, I' long or less, narrowed into short petioles; flowers sessile or nearly so, 4"-6" wide; calyx-lobes lanceolate to ovate-oblong, acute or acuminate, short-horned near the apex; stamens numerous; capsule about as long as the calyx.