Plant of the Month ~~ MARCH 2006
- Common Name(s): Ceanothus, California Lilac, Wild Lilac, Soap Bush, Mountain Lilac, Blue Blossom
- Scientific Name: Ceanothus species
- Family: Rhamnaceae, Buckthorn family
- Plant Type: evergreen or deciduous shrub, or small tree
- Size: 5 to 20 feet high
- Common Habitat: Chaparral, ridges, slopes, woodland, coastal scrub
There are six species of Ceanothus that can be found in the Santa Monica mountains, and about ten times that number of varieties are able to be grown in California. Our natives bloom from January to May. Flower colors range from white to various shades of blue, and are found in clusters. Subtle yet conspicuous, whole hillsides lighten up in the spring when these plants are in bloom.
Characteristically, Ceanothus need good drainage, tolerate cold, heat, and wind, are adapted to fire, and are generally low maintenance. If you have ever done trail maintenance that involved cutting this plant, you may remember the sharp spines on its branches; Ceanothus means spiny plant in Greek. The common name of "Soap Bush" is earned because the flowers of some varieties will develop a lather when rubbed with water.
The following chart gives some distinguishing characteristics of the six kinds native to our mountains.
|Common name||Species||Flowers||Bloom Time||Other characteristics|
|Big-Pod Ceanothus||Ceanothus megacarpus||white||Jan-Apr||very common especially on southern or coastal slopes; gray-brown bark with fluted trunk; oval leaves; fruit is horned; in mid-summer seedpods explode, ejecting seedpods that are its means of reproducing after a fire|
|Greenbark Ceanothus, Redheart Ceanothus||Ceanothus spinosis||light blue to white||Feb-May||Smooth green bark; especially spiny; open-branched or tree-like form; smooth, shiny leaves; fruit is not horned|
|Hairy-Leaf Ceanothus||Ceanothus oliganthus||deeper blue||Feb-Apr||prefers higher, shadier or coastal locations; reddish-tinted branches with tree-like trunk; leaves larger than other varieties, oval, jagged with terminal points; fruit is not horned|
|Hoary-Leaved Ceanothus||Ceanothus crassifolius||white||Jan-Apr||tough plant tolerant of extreme temperatures and drought; open-branched; small, thick, toothed leaves; fruit is horned|
|Buckbrush||Ceanothus cuneatus||white||Feb-May||prefers inland over the coast; erect shrub; wedge-shaped leaves; fruit is horned|
|White Thorn||Ceanothus leucodermis||white to blue||Apr-Jun||not very common; pale green smooth bark; white powdery coating on top of shiny, oval-pointed leaves; fruit is not horned|
Contributed by Liz Baumann
Curious what was featured in past Plants of the Month? Search the Archives.
References:Wildflowers of the Santa Monica Mountains, by Milt McAuley
Flowering Plants: The Santa Monica Mountains, Coastal and Chaparral Regions of Southern California, by Nancy Dale
Roadside Plants of Southern California, by Thomas J. Belzer
California Native Plants for the Garden, by Carol Bornstein, David Fross, and Bart O'Brien
California Herbal Remedies, by LoLo Westrich