Hyssop-leaf Spurge
Euphorbia (Chamaesyce) hyssopifolia
This photo was taken in Phoenix June 2007 and a higher resolution image is hosted at Wikimedia.
ANNUAL: Warm season annual rarely more than 50 cm tall. An upright
spurge with weak arching stems that ooze white sap when broken.
LEAVES: Largest leaves over 15 mm, with serrated edges. Opposite on
stem. Often with reddish splotches.
RANGE: Common weed in urban and agricultural areas in the Sonoran
Desert. Grows better with more water than is generally available in raw desert habitats.
FLOWERS: Minute flowers borne in groups within an involucre. What appears to be petals are actually petal-like glands borne on the rim of the involucre (cup-like structure).
UNARMED: No thorns, but sap can be an irritant.
FRUIT: Small capsules, about 2 mm in diameter, are three-parted.