Euphorbia jejuna

M. C. Johnston & Warnock

SouthW. Naturalist 5: 97, fig. [p. 98]. 1960.

Common names: Dwarf broomspurge
Conservation concern
Synonyms: Chamaesyce jejuna (M. C. Johnston & Warnock) Shinners
Treatment appears in FNA Volume 12. Treatment on page 274. Mentioned on page 255, 261.

Herbs, perennial, with woody or fibrous-fleshy, napiform, branched or tuberous taproot, 3–15 mm thick. Stems ascending to erect, densely emerging from woody crown, 5–15 cm, glabrous. Leaves opposite; stipules connate into lacerate or 2-fid, lanceolate or deltate scale, 0.5–0.9 mm, glabrous; petiole 0.3–0.9 mm, glabrous; blade orbiculate-obovate, ovate, or elliptic, 3–6 (–8) × 1.8–5 mm, base moderately asymmetric, rounded to truncate, margins entire, apex blunt to acute, surfaces glabrous; 2–3-veined from base but usually only midvein conspicuous. Cyathia solitary at distal nodes; peduncle 0.8–1.5 mm. Involucre broadly campanulate, 1.2–1.5 × 0.8–1.2 mm, glabrous; glands 4, yellowish to green or purplish, oblong, 0.2–0.4 × 0.5–1 mm; appendages erect or spreading, white, 0.3–0.6 × 0.8–1.2 mm, usually deeply dissected into 4–5 acuminate lobes, rarely undivided, when divided distal margin rarely entire or crenate. Staminate flowers 12–35. Pistillate flowers: ovary glabrous; styles 0.4–0.5 mm, unbranched thickened-clavate. Capsules ovoid and broadly triangular, 1.8–2.2 (–2.7) × 1.5–2.1 mm, glabrous; columella 1.5–2.2 mm. Seeds whitish, oblong, 4-angled in cross-section, adaxial faces concave, with long raphe between, 1.5–2 (–2.3) × 0.6–0.8 mm, dimpled with faint irregular transverse wrinkles or with up to 10 low, rounded transverse ridges.


Phenology: Flowering and fruiting early spring–summer.
Habitat: Thin calcareous soils (caliche) on limestone hills.
Elevation: 500–900 m.

Distribution

V12 381-distribution-map.jpg

Tex., Mexico (Chihuahua), Mexico (Coahuila)

Discussion

Euphorbia jejuna is known in the flora area from only a few collections in Mitchell, Nolan, Terrell, and Val Verde counties. The species is very similar to E. astyla, but differs in its more deeply divided involucral gland appendages and more definitely petiolate, rounder leaves.

Selected References

None.

Lower Taxa

None.

"connate" is not a number. "distinct" is not a number."connate" is not a number. "distinct" is not a number.

... more about "Euphorbia jejuna"
blunt;acute +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
spreading +  and erect +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
Victor W. Steinmann +, Jeffery J. Morawetz +, Paul E. Berry +, Jess A. Peirson +  and Ya Yang +
M. C. Johnston & Warnock +
rounded to truncate +
Anisophyllum +
0.6 cm6 mm <br />0.006 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
elliptic;ovate;elliptic;ovate;orbiculate-obovate +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
0.22 cm2.2 mm <br />0.0022 m <br /> (0.27 cm2.7 mm <br />0.0027 m <br />) +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.22 cm2.2 mm <br />0.0022 m <br />) +
triangular +  and ovoid +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.21 cm2.1 mm <br />0.0021 m <br />) +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.22 cm2.2 mm <br />0.0022 m <br />) +
Dwarf broomspurge +
Tex. +, Mexico (Chihuahua) +  and Mexico (Coahuila) +
500–900 m. +
pistillate +  and staminate +
yellowish +  and green or purplish +
0.2mm;0.4mm +
subtending +
0.5mm +  and 1mm +
Thin calcareous soils (caliche) on limestone hills. +
axillary +  and terminal +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
campanulate +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
caducous +, deciduous +  and persistent +
bractlike +
acuminate +
palmate +  and pinnate +
toothed +  and entire +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
connate;distinct +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.09 cm0.9 mm <br />9.0e-4 m <br />) +
Flowering and fruiting early spring–summer. +
SouthW. Naturalist +
0 +  and 10 +
rounded +
deltate +, lanceolate +, 2-fid +  and lacerate +
4-angled +  and oblong +
Conservation concern +
free +, connate +  and distinct +
ascending +  and erect +
flattened +  and terete +
5 cm50 mm <br />0.05 m <br /> (15 cm150 mm <br />0.15 m <br />) +
interpetiolar +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.09 cm0.9 mm <br />9.0e-4 m <br />) +
connate +  and distinct +
thickened-clavate +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (?) +  and 0.05 cm0.5 mm <br />5.0e-4 m <br /> (?) +
Chamaesyce jejuna +
Euphorbia jejuna +
Euphorbia sect. Anisophyllum +
species +
axillary +  and terminal +
tuberous +  and branched +
fibrous-fleshy +  and woody +
10 +, 9 +, 8 +, 7 +  and 6 +