Euphorbia fendleri |
Euphorbia commutata |
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Fendler's sandmat |
tinted euphorbia, tinted woodland spurge |
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Habit | Herbs, perennial, with woody, thickened taproot. | Herbs, usually biennial, occasionally annual, with taproot. |
Stems | usually prostrate, decumbent, or ascending, very rarely erect, often densely clustered from top of woody crown, 5–12 cm, glabrous. |
erect or ascending, decumbent and often branched near base, 10–40 cm, glabrous. |
Leaves | usually opposite, rarely whorled; stipules distinct, narrowly linear, 0.5–1 mm, glabrous; petiole 0.5–1 mm, glabrous; blade usually orbiculate to ovate, rarely almost lanceolate, 3–8 × 2.5–7 mm, base slightly asymmetric, slightly cordate to rounded or obtuse, margins entire, apex rounded to obtuse, surfaces glabrous; obscurely 3–5-veined from base, only midvein conspicuous. |
petiole usually 5–10 mm, 0–1 mm distally; blade usually oblanceolate to obovate, rarely ovate, 5–30 × 3–10 mm, base broadly attenuate, margins entire, apex usually obtuse to rounded, occasionally slightly retuse, surfaces glabrous; venation pinnate, midvein prominent. |
Involucre | campanulate to turbinate or broadly cupulate, 1.1–1.7 × 1.2–1.8 mm, glabrous; glands 4, yellow-green to reddish, elliptic to oblong, 0.2–0.5 × 0.4–0.9 mm; appendages absent or white, rarely pink, often unequal, lunate to flabellate or sometimes forming crenate margin along gland, (0–)0.1–0.6 × (0–)0.5–1.5 mm, distal margin entire or toothed. |
campanulate, 1.7–2.5 × 1.5–2.5 mm, glabrous; glands 4, crescent-shaped; 0.6–1 × 0.8–1.5 mm; horns divergent, 0.5–1.1 mm. |
Staminate flowers | 25–35. |
9–15. |
Pistillate flowers | ovary glabrous; styles 0.3–0.4 mm, 2-fid 1/2 length. |
ovary glabrous; styles 0.9–1.3 mm, 2-fid. |
Capsules | depressed-globose, 2–2.4 × 2.2–2.5 mm, glabrous; columella 1.7–2.1 mm. |
ovoid-globose, 2.5–3.2 × 3 mm, slightly lobed; cocci rounded to ± flattened, smooth, glabrous; columella 1.5–2 mm. |
Seeds | white, ovoid-pyramidal, prominently 4-angled in cross section, 1.7–2 × 1–1.2 mm, smooth to slightly wrinkled. |
white to gray, broadly oblong-elliptic to ovoid or nearly globose, 1.5–2 × 1.3–1.6 mm, strongly small-pitted; caruncle irregularly winglike, conic, 0.6–1 × 0.7–0.9 mm. |
Cyathia | solitary at distal nodes; peduncle 0.7–1.2 mm. |
peduncle 0.5–1 mm. |
Cyathial | arrangement: terminal pleiochasial branches (2–)3(–4), 1–3+ times 2-branched; pleiochasial bracts similar in shape and size to distal leaves; dichasial bracts distinct to basally subconnate, not imbricate, widely ovate, rhombic, or reniform, base cordate, rarely slightly perfoliate, margins entire, apex obtuse to rounded, mucronulate; axillary cymose branches 0–5. |
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2n | = 28. |
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Euphorbia fendleri |
Euphorbia commutata |
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Phenology | Flowering and fruiting spring–fall. | Flowering and fruiting spring–summer. |
Habitat | Mountain slopes, desert scrub, pinyon-juniper woodlands, hills, canyons, grasslands, washes, roadsides, dry crevices in limestone, often in gravel and sand. | Bottomland and upland forests, bluffs and ledges, stream banks, glades, rarely fen margins. |
Elevation | 500–2600 m. (1600–8500 ft.) | 50–1000 m. (200–3300 ft.) |
Distribution |
AZ; CA; CO; KS; NE; NM; NV; OK; SD; TX; UT; WY; Mexico (Coahuila)
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AL; AR; FL; GA; IA; IL; IN; KY; LA; MD; MI; MO; MS; NC; OH; OK; PA; SC; TN; VA; WI; WV; ON
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Discussion | Euphorbia fendleri is similar to E. chaetocalyx and may sometimes be confused with that species. Its prostrate to decumbent or ascending stems and small, ovate to orbiculate leaves distinguish it from E. chaetocalyx. Some authors have used the presence or absence and shape of the involucral gland appendages to help separate E. fendleri from E. chaetocalyx, but those characters appear highly variable and of little taxonomic utility; somewhat intermediate individuals occur in western Arizona, New Mexico, and Texas. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 12, p. 267. | FNA vol. 12, p. 300. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > subg. Esula |
Sibling taxa | ||
Synonyms | Chamaesyce fendleri | Galarhoeus austrinus, G. commutatus, Tithymalus commutatus |
Name authority | Torrey & A. Gray: in War Department [U.S.], Pacif. Railr. Rep. 2(4): 175. (1857) | Engelmann: in A. Gray, Manual ed. 2, 389. (1856) |
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