Matted Sandmat

Euphorbia serpens

Description 6

Plants prostrate annuals (will often overwinter); glabrous; plants root just proximal to the nodes; plants may spread to form large sized mats well over a foot; rarely over 5 cm tall. Largest internodes around 1 mm in diameter. Stipules fused to form a scale, usually entire, occasionally divided at the tip. Leaves mostly orbicular to orbicular-rotund, entire and unequal at the base. Cyathia small, usually about 0.5 mm across or less, often difficult to distinguish without getting close to the plant. Glands oval to oblong, about 0.2 mm long. Appendage variable in length, color, and shape. Seeds smooth and plump.

Comments 6

May be easily confused with E. serpens. The only completely accurate means of distinguishing the two is by counting the number of staminate flowers per cyathium: E. albomarginata has more than 10 staminate flowers, E. serpens has fewer than 10. However, there are some other characters that, when combined, can provide a reliable identification most of the time:

E. serpens: Annual (or overwintering); main taproots thin and smooth (even when thickened from overwintering); cyathia small with glands shorter than 0.5 mm, usually not visible to a person when standing.
E. albomarginata: Perennial; main taproots thickened, rough, and woody; cyathia large with glands longer than 0.5 mm, usually visible to a person when standing.

Sources and Credits

  1. (c) nathantaylor, some rights reserved (CC BY-NC-SA), uploaded by Nathan Taylor, http://www.inaturalist.org/photos/5167559
  2. (c) James Bailey, some rights reserved (CC BY-NC), http://www.inaturalist.org/photos/1810552
  3. (c) Nathan Taylor, some rights reserved (CC BY-NC), http://www.inaturalist.org/photos/4752815
  4. (c) nathantaylor, some rights reserved (CC BY-NC-SA), uploaded by Nathan Taylor, http://www.inaturalist.org/photos/5167509
  5. (c) Nathan Taylor, some rights reserved (CC BY-NC), http://www.inaturalist.org/photos/4690073
  6. (c) Nathan Taylor, some rights reserved (CC BY-SA), http://www.inaturalist.org/guide_taxa/346762

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