Page:Ornithological biography, or an account of the habits of the birds of the United States of America, vol 2.djvu/298

262 Individuals of both sexes exhibit considerable difference in the tints of the plumage, at different ages and in different seasons.

Helenidm QUABRiDENTATUM, Willd. Sp. PI. vol. iii. p. 2121, Pursli, Flor. Amer. Sept. voL ii. p. 560. — Stngenesia Polygamia Superflua. CompositjE, Juss.

From three to four feet high, with the stem branched, the leaves decurrent, the lower subpinnatifid, the upper lanceolate, undivided, smooth ; the corollas of the disk four-toothed. This plant springs up spontaneously over aU the abandoned lands of Louisiana, and is very difficult to be extirpated. It is often gathered and burnt, to prevent the musquitoes from entering houses.