A medium-sized tree with attractive foliage made up of ¾-inch by 2-inch short-stalked, slightly staggered oval leaflets numbering 23 or a few less. The phyllotaxy is reminiscent of many eucalyptus branches whose opposite leaf pairs acquire a quarter turn between pairs. In the case of the tipu tree this quarter turn twists the leaflet pairs into the same plane. The leaflets are slightly paler below. Meanwhile the bright yellow flowers produce 3-inch-long by 1-inch-wide pods, like half a maple key, almost as thin as the leaves and at first sight easily mistaken for leaves, though they are a slightly lighter green and add a noticeable accent to the side of the tree in direct sunlight. At the base of each pod a single lump reveals the presence of a hard case containing three kernels. I do not know whether the leaves would have been tasty to a browsing prehistoric animal, in which case the tree might gain an evolutionary advantage by being ingested and later dispersed, or whether the foliage is distasteful, in which case the pea is wearing a disguise.
In the northeast corner of Bowdoin Street and Campus Drive East an expansive specimen inside Rains Houses (at 38 Kirkpatrick Court) overhangs the walls of a secluded courtyard and is visible from both streets. A second specimen occupies the corresponding courtyard 45 yards north. Three more form a splendid group in a lawn at the Hacienda Commons area of Rains Houses. Sometimes referred to as rosewood, an unacceptable name considering that industry already has three rosewoods confirmed by dictionaries (African, Australian, and Brazilian).
Illustrations: single, pinnately-compound leaf of tipu tree, and inflorescence.
About this Entry: The main text of this entry is from the book Trees of Stanford and Environs, by Ronald Bracewell, published 2005.