Desert rocknettle (Eucnide urens) is a native shrub covered with sharp, barbed bristles and hairs. When touched these spines stick like Velcro, but are not particularly irritating. However, when the plant dries the spines sting, burn and are irritating and are extremely difficult to remove from skin. Nevertheless desert bighorn sheep browse desert rocknettle.
Interestingly, aphids that feed on desert rocknettle are not affected by toxins produced by the spines, however, syiphid flies that feed on the aphids are killed by the toxins. The unanswered question, as far as I can tell, is why a plant would produce a toxin that does not kill a pest yet kills an insect that might help control the pest.
A rounded, bushy plant that arises from a stout taproot, desert rocknettle has straw-colored stems. The ovate, coarsely toothed leaves have wrinkled edges.
Desert rocknettle produces hundreds of flowers near the ends of the stems. The pale yellow or white flowers have a greenish tinge. There are 5 separate sepals, five petals and up to 50 stamens joined together in clusters and connected to the base of the petals. The ovary is inferior.
Desert rocknettle fruit is a single-chambered capsule.
This member of the Loasa Family (Loasaceae) can be found between 2,000 and 4,500 feet. It grows in the Mojave Desert at the bases of canyon cliffs, alluvial gravel at the mouths of canyons and in alluvial fans in Southeast California, Southern Nevada, Southwest Utah and Western Arizona as well as into Northern Mexico.
Other common names for E urens include stingbush, desert bush nettle and Velcro plant. The genus name comes from the Greek and means “true nettle”: Eu/good or true and knide/stinging nettle. Stinging or burning is the specific epithet’s translation.
This desert rocknettle was photographed in March along CA Highway 178 near Jubilee Pass in Death Valley National Park CA.