Campanula exigua

Campanula exigua, the chaparral bellflower, rock harebell, or Rattan campanula, is an annual flowering plant in the bellflower family Campanulaceae.
Distribution.
The plant is endemic to Mount Diablo, in the northern Diablo Range within Contra Costa County, in the East Bay region of northern California.
As its common name suggests, chaparral bellflower is a member of the chaparral ecosystem, growing primarily in serpentine soils at elevations of . It grows amongst other Mount Diablo and regional endemic plants, all dependent on natural fire ecology conditions.
Description.
"Campanula exigua" sends up several long stems filled with milky sap and bearing sparse, tiny leaves.
At the end of each stem grows a bell-shaped bright blue-violet flower. The bloom period is May and June.