West side of San Pablo Reservoir, just SE of the boat launch area.
Longitude (DD)
-122.23221
Latitude (DD)
37.916533
Elevation (m)
90
Habitat
Largely open edges in draw-down area around reservoir. Euphorbia was abudant, and Artemisia biennis, Glinus, etc.
Description
Locally common on Euphorbia serpyllifolia. The Euphorbia was locally abundant, and scattered plants were infected and had an upright scraggly appearance instead of being prostrate.
Collection notes
Photos taken and posted to iNaturalist. Another specimen was collected here (CJR5455), which formed dark lesions, and didn't seem to affect the morphology of the Euphorbia.