About Stillingia spinulosa Torr.
Stillingia spinulosa is a species of flowering plant in the euphorb family, commonly called annual toothleaf. It is native to the Southwestern United States, where it grows in creosote scrub of desert areas. It grows as an annual or perennial herb, forming a clump of thick, leafy stems that reach up to nearly one meter in maximum height. Its alternately arranged leaves have shiny, pointed oval blades that measure 2 to 4 centimeters long and up to 1.2 centimeters wide, with sharp teeth lining the edges. The inflorescence is a stout spike of flowers 1 to 2 centimeters long. This plant is monoecious: each spike holds several male flowers at its tip, with 1 or 2 fruit-bearing female flowers positioned below the male flowers. Neither male nor female flowers have petals. The ovary of the female flower develops into a three-lobed greenish capsule about half a centimeter wide. Each of the fruit's three chambers contains one tiny, rough-surfaced seed.
