Euphorbia villifera

Herbs, annual or perennial, with slender taproot or thickened, woody rootstock. Stems usually erect to ascending, rarely prostrate to decumbent, 10–30 cm, papillate, usually villous, sometimes glabrous. Leaves opposite; stipules distinct, filiform, usually undivided, rarely divided into 2–3 segments), 0.3–0.7 mm, glabrous, papillate; petiole 0.6–1.8 mm, usually villous, rarely glabrous; blade ovate, 3–12 × 2–10 mm, base asymmetric, rounded to slightly cordate, margins entire or serrulate, apex acute to obtuse, surfaces usually villous, rarely glabrous; only midvein conspicuous. Cyathia solitary at distal nodes; peduncles 0–1.8 mm. Involucre campanulate, 0.7–0.9 × 0.6–1 mm, glabrous or pilose; glands 4, pink, oval, oblong, or trapezoidal, 0.1–0.2 × 0.2 mm; appendages white to pink, flabellate, oblong, ovate, or nearly rectangular, 0.2–0.4 × 0.2–0.6 mm, distal margin entire. Staminate flowers 10–25. Pistillate flowers: ovary glabrous; styles 0.3–0.5 mm, 2-fid 1/2 to nearly entire length. Capsules oblate-deltoid, cocci often elongated and terminating in an empty portion, 1.5–2 × 2.1–3.1 mm, glabrous; columella 0.9–1.5 mm. Seeds gray-brown to redbrown, ovoid-oblong, weakly 4-angled in cross-section, 1–1.4 × 0.6–0.8 mm, smooth, faintly rugose, or with inconspicuous transverse ridges.

Phenology: Flowering and fruiting early spring–early winter.
Habitat: Riparian forests with walnuts and sycamores, juniper woodlands, pine-oak woodlands, mostly on limestone substrates.
Elevation: 100–1400 m.

Tex., Mexico, Central America

Discussion

Although Euphorbia villifera has been reported from New Mexico (W. C. Martin and C. R. Hutchins 1980), no vouchers to verify its presence there were located. In Texas, E. villifera is known from the Edwards Plateau westward into the trans-Pecos region.

Selected References

None.

Lower Taxa