First leaves are pale green and spatulate. Later emerging leaves have spiny edges and prickly spines along the underside of a prominent midrib. Stem is hollow with milky juice. To top Grass Key Top of page 29. Summer or winter annual.
Cotyledons are kidney-shaped and smooth.
True leaves are alternate and hairy and vary considerably in size and shape. Stem also hairy, especially near base. To top Grass Key Top of page 30. Winter annual or biennial. Cotyledons and early true leaves are round to ovate and are borne on long stalks or petioles.