Photographs by Michael Charters

After Fred Melgert and Carla Hoegen located Eucnide rupestris in this area in the southwestern region of Anza-Borrego County Park, Tom Chester, Nancy Accola, Walt Fidler, Jeff Field and Jim Roberts conducted a survey of Indian Gorge and Torote Canyon, and eventually found eighteen plants of this very rare rock nettle, I joined Tom, Walt and James Dillane a few days later for a re-survey of Indian Gorge and a brief excursion into Mountain Palm Springs Canyon looking for more plants. We did not find any more even though we investigated likely habitats, but it was fun especially for James and myself who had never before seen this elusive species. Rock nettle is a very interesting annual plant that appears to be largely self-pollinated, with an unusual floral structure and characteristics. The road into Indian Gorge is located at mile 46.1 on highway S-2 south of Agua Caliente County Park. These areas were pretty dry, and being January we did not expect there to be a great floristic bloom. The annual rock nettles were apparently germinated by monsoonal rains that fell on September 10 of last year, and ironically they seemed to be among the happiest plants there. I saw no non-native plants in the course of the entire day. Although it's a long drive from Sierra Madre, it was well worth it to see the rock nettle.

Rock nettle
Eucnide rupestris

Eucnide rupestris is an annual species that is found in only a few restricted areas of San Diego and Imperial Counties. The common name rock nettle implies some degree of stinging with regard to the tactile quality of the plant, however I have handled it without feeling any stinging sensation whatsoever. As the picture above shows, the plant is covered with both glandular and barbed hairs and thus most botanists would refer to it as glochdiate, that is, having barbed hairs. The pollination process is unclear but it would appear to be at least partly self-pollinating since the stamens and anthers shown in the upper right picture are sessile in the corolla tube, the stigma is situated among the anthers, and the pollen falls directly on the stigma. The corolla is green. The preferred habitat appears to be rocky talus slopes. It may also be found in Arizona and northern Mexico including Baja. Picture below right taken by James Dillane.


Smoke tree
Psorothamnus spinosus

Encelia farinosa

Strawberry cactus
Mammillaria dioica

Catclaw acacia
Senegalia greggii

Creosote bush
Larrea tridentata

California barrel cactus
Ferocactus cylindraceus

Yuma spurge
Euphorbia setiloba


Copyright © 2017 by Michael L. Charters.
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