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-angled 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), Mexico (Durango), Mexico (Sonora)

Discussion

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

Selected References

None.

Lower Taxa

None.

"connate" is not a number. "distinct" is not a number."/3" is not declared as a valid unit of measurement for this property. "/2" is not declared as a valid unit of measurement for this property.

... more about "Euphorbia bilobata"
sparsely strigillose +  and sericeous +
pink;white;pink;white;greenish +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.14 cm1.4 mm <br />0.0014 m <br />) +
2-fid +, obovate +, oblong +  and ovate +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
Jess A. Peirson +, Victor W. Steinmann +  and Jeffery J. Morawetz +
Engelmann in W. H. Emory +
attenuate +
Alectoroctonum +
elliptic +  and linear to narrowly +
0.8 cm8 mm <br />0.008 m <br /> (5.2 cm52 mm <br />0.052 m <br />) +
unlobed +
0.2 cm2 mm <br />0.002 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
whorled +  and not opposite +
cymose +, few-branched +  and unbranched +
additional +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.26 cm2.6 mm <br />0.0026 m <br />) +
pilose +, strigillose +, puberulent +  and glabrous +
0.21 cm2.1 mm <br />0.0021 m <br /> (0.33 cm3.3 mm <br />0.0033 m <br />) +
exfoliating +
ceraceous +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.21 cm2.1 mm <br />0.0021 m <br />) +
Blackseed spurge +
Ariz. +, N.Mex. +, Tex. +, Mexico (Chihuahua) +, Mexico (Durango) +  and Mexico (Sonora) +
1400–2600 m. +
pistillate +  and staminate +
pink +  and yellow +
0.2mm;0.3mm +
subtending +
u--shaped +
0.4mm +  and 0.5mm +
Sandy and rocky soils on slopes and canyon bottoms in pine-juniper woodlands, oak woodlands, grasslands. +
pleiochasial +  and dichasial +
axillary +  and terminal +
0.09 cm0.9 mm <br />9.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
strigillose +  and pilose +
0.09 cm0.9 mm <br />9.0e-4 m <br /> (0.13 cm1.3 mm <br />0.0013 m <br />) +
alternate +  and opposite +
caducous +, deciduous +  and persistent +
bractlike +
palmate +  and pinnate +
ciliate-strigose +
crenulate +
pilose;strigillose;pilose;strigillose;puberulent;glabrous +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.36 cm3.6 mm <br />0.0036 m <br />) +
connate;distinct +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
strigillose +, sericeous +  and glabrous +
0.1 cm1 mm <br />0.001 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
Flowering and fruiting spring–fall. +
opposite +  and whorled +
with white margins +  and green +
Rep. U.S. Mex. Bound. +
brown;grayish black +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.19 cm1.9 mm <br />0.0019 m <br />) +
tuberculate +
4-angled +, 3-angled +  and ovoid +
0.1 cm1 mm <br />0.001 m <br /> (0.14 cm1.4 mm <br />0.0014 m <br />) +
Weedy +  and Illustrated +
free +, connate +  and distinct +
prostrate +  and decumbent +
strigillose +  and glabrous +
10 cm100 mm <br />0.1 m <br /> (35 cm350 mm <br />0.35 m <br />) +
deciduous +  and persistent +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.02 cm0.2 mm <br />2.0e-4 m <br />) +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (?) +  and 0.08 cm0.8 mm <br />8.0e-4 m <br /> (?) +
inconspicuous +
hairy +  and glabrous +
Agaloma +  and Tithymalopsis +
Euphorbia bilobata +
Euphorbia sect. Alectoroctonum +
species +
in terminal monochasia +  and solitary +
10 +, 9 +, 8 +, 7 +  and 6 +