About Helianthella castanea Greene
Helianthella castanea Greene is a rare plant that is endemic to California. It is only found in the San Francisco Bay Area, where it grows mostly in the hills east of the bay. This range includes Mount Diablo State Park, Wildcat Canyon Regional Park, Briones Regional Park, Las Trampas Regional Wilderness, and the surrounding areas. Its common names are Mount Diablo helianthella, Mount Diablo sunflower, and Diablo rockrose.
This species is a herbaceous plant that grows up to 45 centimeters, or 18 inches, tall. Its leaves can reach up to 15 centimeters, or 6 inches, in length. The plant typically produces just one yellow flower head per stem, and each flower head contains both ray flowers and disc flowers.
