Euphorbia gracillima

S. Watson

Proc. Amer. Acad. Arts 21: 438. 1886.

Common names: Mexican sandmat
Synonyms: Chamaesyce gracillima (S. Watson) Millspaugh
Treatment appears in FNA Volume 12. Treatment on page 270. Mentioned on page 255, 271.

Herbs, annual, with slender taproot. Stems erect to ascending, 5–25 cm, glabrous. Leaves opposite; stipules distinct, subulate-filiform, entire, 0.3–0.5 mm, glabrous; petiole 0.4–0.9 mm, glabrous; blade narrowly oblong to linear, often slightly falcate, 2–15 × 0.3–0.8 mm, base symmetric to subsymmetric, rounded to attenuate, margins entire, thickened and often revolute, apex acute to obtuse, surfaces glabrous; only midvein conspicuous. Cyathia solitary at distal nodes; peduncle 0.1–0.9 mm. Involucre turbinate, 0.4–0.5 × 0.4–0.6 mm, glabrous; glands 4, yellow to pink, oblong to slightly reniform, (0–)0.1–1 × 0.1–0.2 mm; appendages white to pink, ovate to oblong, 0.2–0.4 × 0.1–0.3 mm, distal margin usually entire, rarely emarginate. Staminate flowers 5–12. Pistillate flowers: ovary glabrous; styles 0.1–0.2 mm, 2-fid 1/2 length. Capsules broadly ovoid, 1.1–1.4 mm diam., glabrous; columella 0.8–1.1 mm. Seeds orange to tan or reddish brown, narrowly ovoid, 4-angled in cross section, 0.9–1.1 × 0.5–0.6 mm, smooth.

Phenology: Flowering and fruiting late summer–fall.
Habitat: Rocky slopes and dry washes in desert scrub.
Elevation: 600–900 m.


V12 105-distribution-map.jpg

Ariz., Mexico (Chihuahua, Jalisco, Sinaloa, Sonora).


Euphorbia gracillima occurs from south-central Arizona (Pima and Pinal counties) south through northwestern Mexico.

Selected References


Lower Taxa

... more about "Euphorbia gracillima"
Victor W. Steinmann +, Jeffery J. Morawetz +, Paul E. Berry +, Jess A. Peirson +  and Ya Yang +
S. Watson +
Anisophyllum +
Mexican sandmat +
Ariz. +, Mexico (Chihuahua +, Jalisco +, Sinaloa +  and Sonora). +
600–900 m. +
Rocky slopes and dry washes in desert scrub. +
Flowering and fruiting late summer–fall. +
Proc. Amer. Acad. Arts +
Chamaesyce gracillima +
Euphorbia gracillima +
Euphorbia sect. Anisophyllum +
species +