North Main Divide Road, Santiago Peak, Cleveland National Forest, Orange County, CA. 5-9-09. © Peter J. Bryant

Chaparral Whitethorn
(Whitebark Lilac)

Ceanothus leucodermis

Rhamnaceae

A 6-12 ft. evergreen shrub common to abundant on dry rocky or sandy slopes in chaparral at the highest elevations in the Santa Ana Mountains (Roberts). It has pale green smooth bark with short spreading spiny branchlets. Fruit is sticky,
3-lobed, and lacks horns. Flowering time April-June.

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Idyllwild Nature Center, Riverside Co., CA. 5-31-10. © Joan Avise.
Branches are whitish-gray, ending in spreading, rigid, thorn-like twigs - a distinctive feature that differentiates this species from many others in the group. © Joan Avise.


Flowers are 5-merous, white to blue in 3 in. long clusters.  Idyllwild Nature Center, Riverside Co., CA. 5-31-10. © Joan Avise.
Bell View Trail, E of Robinson Ranch, 2-12-15. © Ron Vanderhoff.

North Main Divide Road, Santiago Peak, Cleveland National Forest, Orange County, CA. 5-9-09. © Peter J. Bryant
North Main Divide Road, Santiago Peak, Cleveland National Forest, Orange County, CA. 5-9-09. © Peter J. Bryant

North Main Divide Road, Santiago Peak, Cleveland National Forest, Orange County, CA. 5-9-09. © Peter J. Bryant
North Main Divide Road, Santiago Peak, Cleveland National Forest, Orange County, CA. 5-9-09. © Peter J. Bryant

Fruits. Left: Ceanothus leucodermis; Right: Ceanothus spinosus. Los Pinos Trail, Upper Trabuco, etc. 4-30-15. © Ron Vanderhoff.
Fruits. Left: Ceanothus leucodermis; Right: Ceanothus spinosus. Los Pinos Trail, Upper Trabuco, etc. 4-30-15. © Ron Vanderhoff.
Associated Insects

European Earwig,
Forficula auricularia
Blood-necked Longhorned Beetle, Callimoxys sanguinicollis
Thrips, Thripidae