A multistemmed deciduous shrub or small tree, native to the Sierra foothills and elsewhere, with magenta flowers that appear in March before the leaves. The flower color alone distinguishes it at a glance from eastern redbud. Flat brown pods, which are still hanging on the tree when the flowers appear in March, contain a few hard, brown, shiny seeds that will take years to germinate unless soaked with boiling water. As boiling water is very rare in nature, this raises an interesting question.
There was a rare clump of four situated in the southwest corner of Santa Teresa Street and Lomita Drive; when the New Guinea sculpture garden was relandscaped in 1994 only one remained, but eastern redbuds were brought in as reinforcements. Western redbud also is at 300 Lowell Avenue, Palo Alto, to the right of the driveway. Just before 2000, dozens of California redbuds were planted in Lomita Mall east of and between the McCullough and Gordon and Betty Moore buildings. It is also growing in the California Native Garden as of 6 May 2006.
You can collect the hard smooth seeds by the hundreds; a bowl of them run through the fingers is at least as therapeutic as a string of worry beads.
Flowers are produced along the branches and trunk before leaves appear.
Illustrations: habit of young tree.
Name derivation: Greek name kerkis, probably for a poplar, but also applied to C. siliquastrum, which through confusion between Judas and Judaea, is now traditionally the trees from which Jesus was hanged; occidentalis – western. – William T. Stearn, Stearn’s Dictionary of Plant Names for Gardeners, Portland, OR.: Timber Press, 1996.
A note on the pea family
The pea family is among the largest flowering plant families with about 18,000 species in 630 genera worldwide. Caesalpina is the type genus for the Fabaceae subfamily Caesalpinioideae, following Cronquist (1981). This subfamily is intermediate in flower morphology between the other two higher-level classifications Mimosoideae and Faboideae (or Papilionoideae). The latter and largest group includes plants with papilionaceous, “butterfly-like”, corollas (with standard, wings, and keel) – as the common garden pea.
All subfamilies are well represented on campus for closer study. Caesalpinioideae and Mimosoideae include mainly tropical trees with pinnately or bipinnately compound, alternate leaves. Mimosoideae flowers are regular (radially symmetrical), the corolla with equal petals often fused into a tube. Campus representatives include Acacia, Albizia, and Gymnocladus. Caesalpinioideae flowers are usually more or less zygomorphic (divisible into equal halves in one plane only). As with Caesalpina spp., the petals are distinct, the uppermost often smaller than the laterals. Other campus members of the subfamily include Bauhinia, Cassia, Cercis, Gleditsia, and Parkinsonia. It would be instructive to work out the higher classification of the many other campus peas (genera listed in the family index) from field observation throughout the year.Further reading: Wendy Zomlefer, Guide to Flowering Plant Families, Univ. of North Carolina Press, 1994
About this Entry: The main text of this entry is from the book Trees of Stanford and Environs, by Ronald Bracewell, published 2005. California garden location and note on pea family subsequently added by John Rawlings.