Slimseed Sandmat (Sandmats (Euphorbia sect. Anisophyllum, previously Chamaesyce) of the Llano Estacado)

Slimseed Sandmat

Euphorbia stictospora stictospora

Description ²

Plants prostrate annuals (ascending in shade or competition); plants hairy; plants typically not more than 15 cm tall; usually forming mats up to 20 cm; plants are generally more robust than C. prostrata and form slightly denser mats. Stem hairs villous; largest internodes 1-2 mm in diameter. Stipules divided on both sides; may be short and difficult to distinguish through hair. Leaves mostly rotund and unequal at the base; serrated; leaves up to about 4 mm long. Cyathia and fruit covered with villous hairs; glands oval to oblong, yellow to red. Appendages usually longer than the gland is wide, entire to crenate, usually white. Seeds pitted.

Habitat and Distribution ²

Common and widespread across the Llano (Turner et. al., 2003). Grows in various but generally disturbed soils. It may be found in soils that are not irrigated but usually not in sand. It may also be a weedy species and grow with E. prostrata and E. maculata but seems to be more tolerant of dry soils. It also seems to be, generally, less abundant than these two in an irrigated lawn or garden.

Comments ²

Plants are most similar to E. prostrata on the Llano. It can be distinguished from it by the following characters:

Euphorbia stictospora: Appendages usually white with yellow or sometimes red glands; hair on capsules dense and curving (villous); seeds pitted.
Euphorbia prostrata: Appendages a light purplish pink with magenta gland; hair on capsules usually not dense and straight (pilose or occasionally curving or even nearly appressed); seeds ridged, not pitted.

There are two varieties of E. stictospora, but variety sublaevis only occurs in Mexico and is much less hairy (nearly glabrous depending on the plant). All the plants on the Llano are variety stictospora.

Sources and Credits

More Info

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