Santa Monica Mountains Trails Council Plants Resource Page

Plant of the Month - Ceanothus

Wild Peony

Ceanothus

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Plant Description

Common Name(s):Ceanothus
Scientific Name:Ceanothus Species
Family:Rhamnaceae
Plant Type:Shrub
Size:5 to 20 feet high
Habitat:Chaparral, ridges, slopes, woodland, coastal scrub
Blooms:November to March

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.

Names
Characteristics
Big-Pod Ceanothus,Ceanothus megacarpus
White flowers blooms from 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 flowers. Blooms from 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 flowers. Blooms from 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 flowers, blooms from Jan-Apr. Tough plant tolerant of extreme temperatures and drought; open-branched; small, thick, toothed leaves; fruit is horned
Buckbrush,Ceanothus cuneatus
White flowers, blooms from Feb-May. Prefers inland over the coast; erect shrub; wedge-shaped leaves; fruit is horned
White Thorn, Ceanothus leucodermis
white to blue flowers, blooms from Apr-Jun. Uncommon; pale green smooth bark; white powdery coating on top of shiny, oval-pointed leaves; fruit is not horned

Contributed by Liz Baumann


Originally featured: March 2006
Last modified: October 14 2017 16:36:00.
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
Images Botanical Terms for Leaves