Basin wiki · Plants
Smoke tree
Psorothamnus spinosus · smoketree
A wash plant that looks like a puff of smoke when it is leafless, and a flood warning when it lines the sand.
Where you'll see it
Smoke trees follow sandy washes and alluvial fans, including washes that cross Highway 62 and the dirt roads of Joshua Tree and Morongo Valley. They are sparse on purpose. A line of them is a map of where water has run, not a landscaping choice. If you are picking a campsite or a building pad, that line is the channel.
How to tell it
For much of the year the plant is a dense tangle of gray, spiny, nearly leafless twigs, which is the smoke look. Leaves, when they appear, are small. Flowers are deep indigo to violet, pea-shaped, and show up in the hot months after summer rain. Nothing else in a basin wash quite has that color. Desert willow in the same wash has long narrow leaves and orchid-like pink flowers; it does not look like smoke.
Flash floods
Washes that support smoke trees still flood. A dry bed at noon can be a brown wall by evening if a storm sits on the Little San Bernardinos or on the highway corridor. Do not park, camp, or store a trailer in the sandy thread between the trees. County roads that dip through those washes, especially north of the highway, close with little warning. The plant is the durable sign; the water is the temporary one.
Leave the roots
Smoke trees are deep-rooted specialists. Pulling one because it is “just a dead-looking bush” removes the thing that stabilizes that bank. They are poor candidates for an ordinary yard away from a wash: the site, not the hose, is what they want. Calflora is the occurrence map if you are trying to confirm a plant you photographed.