Chamaesyce petrina

A prostrate, greyish-leaved mat-forming Chamaesyce found in Sonora and Baja California, not extending north into the United States. My identification is somewhat tentative; this plant keys to C. petrina in Steinmann's "Euphorbiaceae of Sonora", but does not key out cleanly to any species in Wiggins' "Flora of Baja California".

Plant habit about 10 miles west of Bahia de Los Angeles in Baja California, 10/21/06.

Cyathia about 10 miles west of Bahia de Los Angeles, 10/21/06.

Cyathia, west of Bahia de Los Angeles, 10/21/06.

Flowering stems, west of Bahia de Los Angeles, 10/21/06.