About Ceanothus impressus Trel.
Ceanothus impressus Trel. is a species of shrub in the buckthorn family Rhamnaceae, with the common name Santa Barbara ceanothus. This species is endemic to the Central Coast of California, occurring only in San Luis Obispo and Santa Barbara Counties, where it grows in chaparral habitat. It is an upright shrub that can grow up to 3 meters tall, and can take either a dense or open growth form. Its evergreen leaves are oval-shaped, roughly 2 centimeters long, marked by prominent wrinkled ridges, with curled under edges. Leaves may have gland dots, and their undersides are covered in light gray hairs. The shrub produces abundant clusters of small blue flowers in inflorescences. Its fruit is a spherical, crested capsule around 4 millimeters wide. Two varieties are recognized: Ceanothus impressus var. impressus, which is generally more compact, with intricate branching and cupped leaves; and Ceanothus impressus var. nipomensis, common name Nipomo ceanothus, which is a rare, more open-shaped variety found only in a region of San Luis Obispo County.
