FLORA OF THE VALLEY : HORSEBRUSH

Horsebrush, a leafy, rigid shrub, can be found on the higher, dry slopes in the mountains of Southern California deserts.

Horsebrush (Tertradymia canescens) resembles many other species that flourish in the same type of habitat and belong to the same composite family. It reaches heights of a foot or more and has an unusual fragance.

The plant’s narrow, linear leaves, which are covered with white wool, average about an inch long. The leaves, which curl when dry, alternate on the plant’s woolly stems.

In the fall, horsebrush, which grows in clumps, is topped by hundreds of tiny yellow flowers growing in loose clusters. Each plant head has four flowers--each with yellow petals and yellowish, hairy bristles. The flowers are of the disk variety.

Pictured here is horsebrush along the Little Tujunga Canyon, high in the mountains above Sylmar. Flowers and leaves have been enlarged many times to show detail. The plant also is common, in altitudes from 4,000 to 10,000 feet, in the San Bernardino Mountains.

Similar species, members of the composite family to which horsebrush belongs, flower about the same time as horsebrush, making the the plant difficult to identify. Among those similar varieties are three kinds of rabbit brush, all more common on Southern California’s mountain slopes than horsebrush. All have small, yellow disk flowers. One species has as many as 15 flowers a head.