California Code, Government Code - GOV § 39561.5

(a) Weeds which bear seeds of a downy or wingy nature.

(b) Sagebrush, chaparral, and any other brush or weeds which attain such large growth as to become, when dry, a fire menace to adjacent improved property.

(c) Weeds which are otherwise noxious or dangerous.

(d) Poison oak and poison ivy when the conditions of growth are such as to constitute a menace to the public health.

(e) Dry grass, stubble, brush, litter, or other flammable material which endangers the public safety by creating a fire hazard.