Euphorbia bilobata

Engelmann

in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 190. 1859.

Common names: Blackseed spurge
WeedyIllustrated
Treatment appears in FNA Volume 12. Treatment on page 243. Mentioned on page 241, 244.

Herbs, annual, with slender taproot. Stems erect, branched, 10–35 cm, glabrous or strigillose (especially when young and around nodes). Leaves opposite proximally, alternate distally; stipules 0.1–0.2 mm; petiole 1–4(–6) mm, glabrous, sericeous or strigillose; blade linear to narrowly elliptic, 8–52 × 2–7 mm, base attenuate, margins entire, ciliate-strigose, apex acute, abaxial surface sparsely strigillose to sericeous, adaxial surface usually glabrous; venation obscure, only midvein conspicuous. Cyathia solitary at distal nodes or in weakly defined cymes or dichasia, dichasial bracts and distal stem leaves wholly green; peduncle 0.5–3.6 mm, strigillose. Involucre obconic, 0.9–1.5 × 0.9–1.3 mm, strigillose to pilose; glands 5, yellow or pink, U-shaped, 0.2–0.3 × 0.4–0.5 mm; appendages greenish, white, or pink, forming narrow rim around gland, or ovate, oblong, or obovate and usually 2-fid, rarely rudimentary, 0.2–1.4 × 0.2–0.6 mm, entire. Staminate flowers 20–25. Pistillate flowers: ovary glabrous, puberulent, strigillose, or pilose; styles 0.5–0.8 mm, 2-fid 1/3–1/2 length. Capsules oblate, 1.5–2.6 × 2.1–3.3 mm, glabrous or puberulent, strigillose, or pilose; columella 1.2–2.1 mm. Seeds brown to grayish black, narrowly ovoid, 3- or 4-angled in cross section, sometimes obscurely so, 1.3–1.9 × 1–1.4 mm, tuberculate, often with shallow depressions; caruncle absent. 2n = 32.


Phenology: Flowering and fruiting spring–fall.
Habitat: Sandy and rocky soils on slopes and canyon bottoms in pine-juniper woodlands, oak woodlands, grasslands.
Elevation: 1400–2600 m.

Distribution

V12 89-distribution-map.jpg

Ariz., N.Mex., Tex., Mexico (Chihuahua, Durango, Sonora).

Discussion

In Texas, Euphorbia bilobata is known only from Jeff Davis County.

Selected References

None.

Lower Taxa

None.
... more about "Euphorbia bilobata"
Jess A. Peirson +, Victor W. Steinmann +  and Jeffery J. Morawetz +
Engelmann +
Alectoroctonum +
Blackseed spurge +
Ariz. +, N.Mex. +, Tex. +, Mexico (Chihuahua +, Durango +  and Sonora). +
1400–2600 m. +
Sandy and rocky soils on slopes and canyon bottoms in pine-juniper woodlands, oak woodlands, grasslands. +
Flowering and fruiting spring–fall. +
in W. H. Emory, Rep. U.S. Mex. Bound. +
Weedy +  and Illustrated +
Agaloma +  and Tithymalopsis +
Euphorbia bilobata +
Euphorbia sect. Alectoroctonum +
species +