More often planted than our native California western redbud and more showy. It volunteers freely on campus, for example on Stanford Avenue. The seed pods are narrower than those of California redbud and fall off earlier. The heart-shaped 5-inch leaf blade is broader than it is long, darker green above than below, and has a sharp tip. Western redbud has a similar leaf but rounded at the tip or slightly notched. Strikingly, flowers are produced along the branches and trunk before leaves appear. The related C. siliquastrum is called the Judas tree since Judas Iscariot reportedly hanged himself from one (see Name derivation below).
See eastern redbuds on Santa Teresa Street at the New Guinea Garden, and between the McCullough and Gordon and Betty Moore buildings with western redbud. The two species are paired in the roundabout on Escondido Road and Campus Drive as well: three single-trunked westerns with one multitrunk eastern. In Palo Alto, a specimen at 1031 Hamilton Avenue is actually around the corner on Chaucer Street.
Cultivar ‘Forest Pansy’ has distinctive reddish purple leaves, but puts on more of a muted show when in flower. Several were part of the original landscaping of the Knight Management Center which opened spring 2011.
Name derivation: Cercis – 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; canadensis – of Canada. – 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. Note on Forest Pansy and note on pea family added by John Rawlings. Additional locations, minor edits Mar 2017 (SP).