Ambrosia pumila (Nutt.) A. Gray

Ambrosia pumila (Xutt.) A. Gray, Proc. Am. Acad. 17: 217
1882.
Franseria pumila Nutt. Trans. Am. Phil. Soc. II. 7: 344. 1840. Hemiambrosia heterocephala Delpino, Studi Lign. Anem. 61. 1871.
A perennial herb, with a rootstock; stems 1-2 dm. high, silky-canescent; leaves mostly alternate, bipinnatifid or tripinnatifid, grayish silky-canescent; petioles 2-3 cm. long; blades broadly ovate in outline; divisions linear or linear-oblong; staminate heads rather few in terminal racemes; involucre saucer-shaped, 4 mm. broad, crenately 5-6-toothed on the margin, canescent; paleae of the receptacle few, linear, with spatulate pubescent tips; corolla glandularpuberulent; pistillate heads in small clusters in the upper axils; fruit pubescent, obovoid, unarmed, 2 mm. long.
Type locality: San Diego, California.
Distribution: Southern California and Lower California.