''Ceanothus sonomensis'', with the common name Sonoma ceanothus, is a rare species of
shrub
A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...
in the family
Rhamnaceae
The Rhamnaceae are a large family of flowering plants, mostly trees, shrubs, and some vines, commonly called the buckthorn family. Rhamnaceae is included in the order Rosales.
The family contains about 55 genera and 950 species. The Rhamnaceae h ...
. It is
endemic to northern
California.
Description
The ''Ceanothus sonomensis'' shrub is erect in form, approaching a maximum height of one meter. The flat evergreen leaves are oppositely arranged, each oval to rounded in shape with spiny teeth along the edges. They are shiny green on top, paler and fuzzy on the undersides. The
inflorescence is a small cluster of blue or lavender flowers, and the fruit is a ridged, horned capsule about half a centimeter long.
Distribution
''Ceanothus sonomensis'' is known only from the
Hood Mountain Range. Most of its 10 or so occurrences are located in
Sonoma County, and one remains in
Napa County.
California Native Plants Society Rare Plant Profile
/ref> ''Ceanothus sonomensis'' is a member of the chaparral
Chaparral ( ) is a shrubland plant community and geographical feature found primarily in the U.S. state of California, in southern Oregon, and in the northern portion of the Baja California Peninsula in Mexico. It is shaped by a Mediterranean c ...
plant community in the California montane chaparral and woodlands sub- ecoregion.
References
External links
Jepson Manual Treatment - ''Ceanothus sonomensis''USDA Plants Profile: Ceanothus sonomensis''Ceanothus sonomensis'' - Photo gallery
sonomensis
Endemic flora of California
Natural history of the California chaparral and woodlands
Natural history of the California Coast Ranges
Natural history of Sonoma County, California
Plants described in 1939
Taxa named by John Thomas Howell
{{Rhamnaceae-stub