This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", 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..
[Hydrolea L. Sp. Pl. Ed. 2, 328. 1762.]
Perennial herbs, some tropical species shrubby, with alternate entire leaves, sometimes with spines in their axils, and b!ue cymose-clustered or racemose flowers. Calyx-segments distinct to the base, ovate or lanceolate. Corolla rotate-campanulate, not appendaged within, 5-cleft, the lobes imbricated in the bud. Stamens inserted on the base of the corolla; filaments filiform, dilated below; anthers sagittate. Ovary 2-celled (rarely 3-celled); ovules numerous in each cavity, on fleshy adherent placentae; styles 2, rarely 3, slender or filiform, distinct to the base; stigma capitellate. Capsule globose or ovoid, septicidally or irregularly dehiscent.
About 15 species, natives of warm and tropical regoins of both the Old World and the New. Besides the following, another occurs in the southern United States. Type species: Nama zeylanica L.
Leaves lanceolate; flowers mostly in axillary clusters.
Glabrous, or very nearly so, throughout; sepals ovate to ovate-lanceolate.
1. N. affinis.
Villous, at least above, and on the calyx; sepals lanceolate.
2, N. quadrivalvis.
Leaves ovate; flowers mostly in terminal clusters; sepals villous.
3. N. ovata.
Hydrolea affinis A. Gray, Man. Ed. 5, 370°. 1867. Nama affinis Kuntze, Rev. Gen. Pl. 435. 1891.
Glabrous or very nearly so throughout, with or without slender spines in the axils; stems ascending, 1° - 2 1/2° high. Leaves oblong-lanceolate, petioled, acute or acuminate at both ends, 2-5' long, 4"-%" wide; flowers 6"-7" broad, short-pedicelled, in rather dense peduncled leafy-bracted axillary clusters; sepals ovate or ovate-lanceolate, acute or acuminate, about equalling the corolla; capsule 2" in diameter when mature, somewhat longer than the styles, shorter than the sepals.
In wet places, southern Illinois to Missouri, Louisiana and Texas. June-Aug.
Similar to the preceding species, but pubescent, at least above, and on the calyx, with spreading hairs, usually bearing slender spines in the axils; stem ascending, 1°-2° high. Leaves lanceolate, acute or acuminate, glabrous, or sparingly pubescent, petioled, 2-5' long, 3"-8" wide; lower petioles i' long, or more; flowers in axillary clusters; sepals lanceolate or linear-lanceolate, acuminate, about as long as the corolla; capsule 2"-3" in diameter, longer than the styles, about the length of the sepals.
In wet soil, southeastern Virginia to Florida and Louisiana. June-Aug.
Stem erect or nearly so, 1°-3° high, usually branched near the summit, puberulent, or somewhat hirsute, at least above, usually spine-bearing in most of the axils. Leaves ovate, rarely ovate-lanceolate, puberulent or glabrous, short-petioled, or the upper almost sessile, 1'-21/2' long, 1/2'-1 1/4' wide, acute at the apex, narrowed or rounded at the base; flowers often 1' broad or more, in terminal clusters; sepals lanceolate, acuminate, very villous, shorter than the corolla, longer than the capsule; styles longer than the sepals.
In wet soil, Georgia to Missouri, Louisiana and Texas. May-Sept.