Parkinsonia aculeata
Jerusalem thorn

Fabaceae (pea family)
Tropical America
Parkinsonia aculeata fruit, leaves, flowers, seed. From Forest Trees of the Pacific Slope, George B. Sudworth, USDA, 1907

A deciduous desert tree, with characteristic pea-family pinnate leaves modified for dry conditions. The leaflets, normally up to a foot long, are much reduced in size (about ⅛ inch) and very numerous (40 to 80) if present at all (the plant often gets along with the interestingly shaped leaf rachis only). Yellow ½-inch flowers come in racemes standing several inches high. The seed pods are several inches long, constricted between the seeds. No examples are known on campus, but in Palo Alto three specimens are in front of 586 College Avenue and another is at Palo Verde Elementary School, 3450 Louis Road. Walk in the main entrance and see the tree on the right in the courtyard just beyond the principal’s office.

Name derivation: Parkinsonia – after John Parkinson (1567–-1650), London apothecary and author of gardening books; aculeata – prickly.

About this Entry: The main text of this entry is from the book Trees of Stanford and Environs, by Ronald Bracewell, published 2005.