Bursera microphylla

This plant is relatively rare throughout its range from southwestern Arizona and southern California into Mexico. Over 100 EOs in the world but not apparently secure any where. EOs in Mexico are abundant but virtually none are protected. CA EOs are very small. The remoteness of its habitat will probably confer long-term stability. Collecting branches and bark for medicinal purposes has the potential to reduce individual populations; but the potential is low since collectors typically remove small parts of vegetative tissue such as portions of branches, a few leaves, or resin.

In Arizona, Bursera microphylla grows from Kitt Peak Observatory west to the Telegraph Mountains near Yuma and as far north as the Casa Grande mountains. California populations are restricted to Imperial and San Diego counties, and in Mexico are most abundant around the Sea of Cortez in Baja and Sonora. B. microphylla also grows in significantly remote pockets of the Tinajas Altas, sierra Estrellas, Growler, and Mohawk mountain ranges (Moore 1989).

Rare in CA, widespread in Mexico. 13 known EOs in CA, but many to the south in Baja; few threats.

The estimated impact on wild population viability caused by collecting this plant for medicinal purposes is probably low. Two major stands are protected in Arizona (Moore 1989) and many plants grow in extremely remote areas throughout mountain ranges in the southwestern U.S. that are relatively unsuitable for other uses. Apparently, taking a branch or collecting resin exuding from the tree trunks provides sufficient quantities of material for medicinal use. Therefore, its remote habitat coupled with relatively non-destructive collecting requirements suggests that threats resulting from the herbal industry are minimal. However, this species is relatively rare, so ecological threats to its habitat should be monitored. California believes there may be some undocumented horticultural collecting of entire plants.