The American threefold (Trixis californica) belongs to Asteraceae (the Aster family). It is an evergreen shrub that is native to the southwestern United States and Mexico. This shrub grows in rocky hillsides, thorn scrub, desert washes and brush, and up to a height of 60-90 cm. The stems are sprawling. The leaves are lanceolate, dark green, 2-11 cm long, and 0.5-3 cm wide. The yellow flower-heads bloom in a panicle or corymb, from February and October. The flower-head contains between 11 and 25 individual flowers. The each floret is bilabiate with two asymmetrical lips with one larger than the other. The floral lips turn whitish as they age.