Flora and Fauna News

Cassias Giving Splash of Yellow to Urban Landscapes
By Michael Plagens Sonoran Desert Sciences
PHOENIX, Az. -----     Several species of xericly adapted Cassias are widely planted in the urban areas of Phoenix and Tucson. These have now begun blooming profusely adding color to our roadsides and yards. These plants are very hardy having evolved in the Australian deserts, but would not be heavily blooming most years without some irrigation. They belong to the plant family Fabaceae which includes beans, mesquites, and palo verdes. But like palo verdes, they also belong to the subfamily Caesalpinioideae. On rare occassions a few bees, such as the large black Carpenter Bees and domestic Honey Bees will visit the flowers. Occasionally the caterpillars of the Cloudless Sulfur butterfly will be found eating the leaves although it may be toxic to them. According to U of A extension employee Cheri Melton, these Australian species are toxic to the larvae. Otherwise, these exotic plants do not contribute much to the Sonoran Desert ecology. Late February Rains     Beginning Saturday, February 21, a series of Pacific weather systems began pushing through the Desert Southwest providing some significant rainfall. As usual the actual amounts vary widely from area to area, but this water will revive the spring annuals that have been stunted and wilting from low moisture. Pretty good wildflower blooms should begin appearing within two weeks. Even now several dozen species will be found in bloom at most desert locations, albeit upon smallish plants and awidely dispersed spots. The best places to look are at roadsides and adjacent to exposed, impermiable rock layers.