Thurber's Pilostyles

Thurber’s pilostyles (peh-LOSS-teh-lees) is an internal parasite. It lives inside the host plant. It doesn’t kill the host but dies inside it. The evidence is inconclusive as to why.

In Anza-Borrego, its tiny 2-mm flowers can be found in December or January (sometimes even November) on the lower branches of dyeweed (Psorthamnus emoryi). By late winter or spring, the flowers are visible but dry. Eventually, they drop off, leaving black scars on the host plant’s branches. Obviously, for best viewing of the flowers, you’ll want to use your camera’s macro lens, or else a hand lens.