Xanthium spinbsum - Family, Composite. Color, greenish yellow. Staminate and pistillate flowers in different heads, the former in small heads above, making short spikes, the latter axillary below. Corolla, attending the single pistil, long, thread - like. Pistillate heads covered with stout, hooked spines, which, in fruit, make a rough, pointed, beaked, bristly bur. Stem 1 to 3 feet high, thickly covered with lobed or toothed, alternate leaves and stout branches. There are spines at the base of the leaves, slender, of a yellow color, 3-parted. August to November.