Euphorbia bifurcata

Engelmann in W. H. Emory

Rep. U.S. Mex. Bound. 2(1): 190. 1859.

Common names: Forked spurge
Illustrated
Treatment appears in FNA Volume 12. Treatment on page 319. Mentioned on page 239, 317, 318.

Herbs, annual, with slender, fibrous taproot. Stems erect, 20–70 cm, glabrous or with few scattered spreading hairs; branches arcuate, branching appearing dichotomous. Leaves usually alternate, occasionally opposite at proximalmost node; petiole 15–49 mm, glabrous; blade usually ovate, rarely oblong or elliptic, 13–54 × 7–38 mm, base usually rounded to broadly cuneate, rarely truncate, margins finely serrulate, apex obtuse, surfaces glabrous or with few scattered hairs; venation pinnate, midvein prominent. Cyathial arrangement: terminal dichasial branches 2, few-branched (weakly defined); pleiochasial bracts 2–3, opposite or whorled, wholly green, similar in shape and size to distal leaves; dichasial bracts smaller than distal leaves, often white at base. Cyathia: peduncle 0.9–3.5 (–6.2) mm. Involucre tubular or obconic, 1–1.7 × 0.7–1.4 mm, glabrous except for few hairs on lobes; involucral lobes divided into several linear, smooth lobes; glands 1 (–3), greenish, sessile and broadly attached, 0.3–0.4 × 0.4–0.8 mm, opening oblong to subcircular, glabrous; appendages petaloid, white, elliptic, oblong, transversely oblong, or forming thin, lunate rim on gland margin, not incurved and covering glands, 0.3–0.9 × 0.6–1.3 mm, entire, undulate or slightly lobed, glabrous. Staminate flowers 20–30. Pistillate flowers: ovary glabrous; styles 0.6–1 mm, 2-fid 1/2 length. Capsules oblate, 2.8–3.1 × 3.6–4.5 mm, glabrous; columella 1.9–2.4 mm. Seeds brown to blackish, ovoid, rounded in cross-section, 1.9–2.4 × 1.5–1.8 mm, irregularly and coarsely tuberculate; caruncle absent or rudimentary.


Phenology: Flowering and fruiting summer–fall.
Habitat: Riparian areas with cottonwoods and willows, pinyon pine woodlands, pine-oak forests, Douglas fir forests with pines.
Elevation: 1900–2300 m.

Distribution

V12 702-distribution-map.jpg

N.Mex., Tex., Mexico, Central America (Guatemala)

Discussion

Euphorbia bifurcata is found in the mountains of southern New Mexico (Doña Ana, Grant, Lincoln, Otero, and Sierra counties) and trans-Pecos Texas (Brewster, Jeff Davis, and Presidio counties).

Selected References

None.

Lower Taxa

None.

"thin" is not a number.

... more about "Euphorbia bifurcata"
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.09 cm0.9 mm <br />9.0e-4 m <br />) +
lobed +, undulate +, entire +  and oblong +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.13 cm1.3 mm <br />0.0013 m <br />) +
Jess A. Peirson +, Paul E. Berry +  and Victor W. Steinmann +
Engelmann in W. H. Emory +
connate +
usually rounded +  and broadly cuneate +
Poinsettia +
1.3 cm13 mm <br />0.013 m <br /> (5.4 cm54 mm <br />0.054 m <br />) +
elliptic;oblong;ovate +
7mm;38mm +
dichasial +  and pleiochasial +
whorled +  and opposite +
white +  and green +
distinct +
2 (?) +  and 3 (?) +
smaller +
dichotomous +  and branching +
arranged +  and opposite +
additional +
0.28 cm2.8 mm <br />0.0028 m <br /> (0.31 cm3.1 mm <br />0.0031 m <br />) +
0.36 cm3.6 mm <br />0.0036 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
0.19 cm1.9 mm <br />0.0019 m <br /> (0.24 cm2.4 mm <br />0.0024 m <br />) +
Forked spurge +
N.Mex. +, Tex. +, Mexico +  and Central America (Guatemala) +
1900–2300 m. +
pistillate +  and staminate +
0.3mm;0.4mm +
subtending +
oblong +  and subcircular +
0.4mm +  and 0.8mm +
Riparian areas with cottonwoods and willows, pinyon pine woodlands, pine-oak forests, Douglas fir forests with pines. +
axillary +  and terminal +
0.1 cm1 mm <br />0.001 m <br /> (0.17 cm1.7 mm <br />0.0017 m <br />) +
obconic +  and tubular +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.14 cm1.4 mm <br />0.0014 m <br />) +
caducous +, deciduous +  and persistent +
bractlike +
involucral +
divided +
palmate +  and pinnate +
toothed flat +  and revolute +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.62 cm6.2 mm <br />0.0062 m <br />) +
0.09 cm0.9 mm <br />9.0e-4 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
connate;distinct +
1.5 cm15 mm <br />0.015 m <br /> (4.9 cm49 mm <br />0.049 m <br />) +
Flowering and fruiting summer–fall. +
Rep. U.S. Mex. Bound. +
lunate +
0.19 cm1.9 mm <br />0.0019 m <br /> (0.24 cm2.4 mm <br />0.0024 m <br />) +
tuberculate +
rounded +  and ovoid +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
Illustrated +
free +, connate +  and distinct +
20 cm200 mm <br />0.2 m <br /> (70 cm700 mm <br />0.7 m <br />) +
deciduous +  and persistent +
distinct +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (?) +  and 0.1 cm1 mm <br />0.001 m <br /> (?) +
with few scattered hairs +  and glabrous +
Euphorbia bifurcata +
Euphorbia sect. Poinsettia +
species +
few-branched +  and dichasial +