Acacia dealbata · silver wattle · Tasmania, Victoria, New South Wales, Queensland
Acacia decurrens · green wattle · New South Wales, Queensland
The brilliant yellow displays in February and March, which distinctly precede the coming of spring and add color to the winter’s end, are mainly from these species.
The feathery leaves are divided into a dozen or so pinnae each with three dozen or so pinnules about ⅙ inch long. At the point of attachment to the branch, the leaf stalks of green wattle run on as definite ridges on the branch. Green wattle also has a rough, dark or black trunk. Many of the campus trees do not exhibit the silvery-gray foliage of silver wattle, but neither do they possess the prominently ridged stems and dark trunk of green wattle. There is a large leaning specimen on Governor’s Avenue where it makes a corner at Lake Lagunita and substantial numbers can be found in the area of Frenchman’s and Gerona Roads. There is one on Campus Drive at the southeast corner with Lomita Drive. Acacia dealbata is an invasive weed in Bear and San Francisquito creeks in Jasper Ridge Boiogical Preserve and along other campus waterways.
Both species have glands on the leaf main axis at the junction of each pair of first leaflets, as shown. (The leaves of these trees are twice-pinnately compound). The twigs of A. dealbata are finely hairy, and more or less angular without wings.
Illustrations: Jasper Ridge plant photo archive
Name derivation: Acacia – Greek akis, a sharp point; dealbata – whitened (young shoots and leaves).
About this Entry: The main text of this entry is from the book Trees of Stanford and Environs, by Ronald Bracewell, published 2005. The sentence “I have concluded that I cannot tell one from the other and look forward to being instructed” was replaced by some notes on the glands and twigs by John Rawlings (c 2010).