Clarkia rubicunda, Ruby Chalice Clarkia
Also called "Herald-of-Summer," this long-blooming showy pink-lavender clarkia has distinctive flowers with a dark red blotch at the base of the petals. Flower stalks 12 to 18 inches, so this is one of the shorter clarkias, very nice at the front of a planting of several different clarkia species, or of other taller wildflowers. Handles full sun.
If sown later in the winter, this clarkia can bloom as late as September on the coast. The seed is tiny. One packet contains hundreds of seeds. It is found in many parts of central and north-central California, and Marin County is its northern limit.