The Biology of Dianthera americana L.

Abstract

Gray's Manual of Botany states that it is to be found water, Que. to Wise, and Vt., s. to Ga. and Tex. July-Sept. Small's Manual of the Southeastern Flora states that it occurs on beds, shores, and banks of streams, various provinces, Ga. to Tex., Mich., and Que.-Spr.-Sum. It is to be noted that it occurs throughout most of Eastern United States east of the Mississippi River. It is found abundantly throughout the reservoirs of the Tennessee Valley Authority, but is uncommon in the upper part of the Valley. Habitat.?As has been stated by Small (1933) it occurs on beds, shores, and banks of streams. It thrives best in streams of considerable flow and is never found in stagnant ponds. Dianthera is, however, well established in Lake Wilson, a reservoir of the Tennessee Valley Authority (Fig. 1). This so-called lake is a section of the Tennessee River, the water level of which was elevated by the completion of Wilson Dam in 1925. The species is present also in the river of the Alabama Power Company on the Coosa and Tallapoosa Rivers. Although it occurs in these reservoirs, it has never been observed in natural ponds or lakes in the watershed of the Tennessee River.