Excerpts from Jim Conrad's
adapted from the May 1, 2005 Newsletter issued from the Sierra Nevada foothills
somewhat east of Placerville, California, USA
It's hard to believe that this is a clover because of the flat head of flowers and skinny leaflets (as shown at the bottom left of the picture). However, the flowers are structured exactly like clover flowers, and you'll note that the leaflets come in 3s, just like other clovers.
This is TRIFOLIUM VARIEGATUM, of found growing in lawns and other disturbed or rocky places. Flowers from mid to late spring.