Erect or trailing plant with slender stems and a twining growth habit. Leaves are narrow, covered with short, stinging hairs and have jagged margins. Tiny red to reddish-green flowers with yellow stamens grow in clusters at the top of the flower stalk.
Stems dark green or whitish, reddish or grayish; leaves simple, can be lobed basally, margins coarsely toothed to serrate; flower clusters terminal; glands sessile or absent; male flowers 8 to 40 per stalk, sepals reddish green, stamens 3 to 6, up to 10.
Habitat
Found in canyons, desert washes (areas with spiny shrubs and intermittent streams), open rocky slopes, hillsides, valley floors and pine-oak woodlands.
Flower Characteristics
Male and female flowers grow on the same plant at the top of the flower stalk. 8 to 40 male flowers each with 3 or 4 leaf-like sepals and 0 petals grow above 1 to 2 female flowers with 6 sepals and 0 petals. Reddish-green sepals are bent backwards.
Leaf and Stem Characteristics
Leaves are often lance-shaped, at times triangular, are about 1/2 to 1-1/2 inches long and have rough, bristly hairs. Stems are dark green or whitish, reddish or grayish, have curvy tops and are covered with coarse hairs that sting the skin if touched.
Fruit and Seed Characteristics
The fruit is dry, has 3 lobes (segments) each containing 1 seed, is about 1/4 to 1/2 inch wide and is covered with stiff, stinging hairs. When ripe, the fruit ejects the seeds forcefully in a process called "explosive dehiscence" widely dispersing them.
The seeds are sphere-shaped, smooth, brownish-black and each is about 1/16 of an inch wide.