Euphorbia crenulata |
Euphorbia commutata |
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Chinese caps, western wood spurge |
tinted euphorbia, tinted woodland spurge |
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Habit | Herbs, usually biennial, occasionally annual, with taproot. | Herbs, usually biennial, occasionally annual, with taproot. |
Stems | erect, sometimes decumbent at base, unbranched or branched, 12–40 cm, glabrous. |
erect or ascending, decumbent and often branched near base, 10–40 cm, glabrous. |
Leaves | petiole 0–2 mm; blade obovate-spatulate to oblanceolate, 8–22 × 3–10 mm, base broadly attenuate, margins entire or slightly crisped, apex obtuse to ± rounded, minutely apiculate, surfaces glabrous; venation pinnate, midvein prominent. |
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, 1.8–2.1 × 1.6–1.8 mm, glabrous; glands 4, crescent-shaped, 0.6–1.2 × 1.5–2.3 mm; horns slightly divergent to slightly convergent, 0.4–0.6 mm. |
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 | 11–18. |
9–15. |
Pistillate flowers | ovary glabrous; styles 0.9–1.4 mm, 2-fid. |
ovary glabrous; styles 0.9–1.3 mm, 2-fid. |
Capsules | subovoid, 2.5–3 × 3.5–4 mm, 3-lobed; cocci rounded, smooth or puncticulate, glabrous; columella 1.9–2.3 mm. |
ovoid-globose, 2.5–3.2 × 3 mm, slightly lobed; cocci rounded to ± flattened, smooth, glabrous; columella 1.5–2 mm. |
Seeds | cream and brown mottled, oblong-ovoid to nearly globose, 2–2.5 × 1.4–1.7 mm, usually irregularly vermiculate-ridged and large-pitted, occasionally tuberculate or nearly smooth; caruncle reniform, conic, 0.5–0.6 × 0.5–0.7 mm. |
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. |
Cyathial | arrangement: terminal pleiochasial branches 3, each 2-branched; pleiochasial bracts obovate to orbiculate-reniform, wider than distal leaves; dichasial bracts usually connate 1/3–1/2 length (often only on one side), rarely only connate basally, triangular ovate to reniform, base truncate to perfoliate, margins erose-denticulate to subentire, apex rounded to obtuse, rarely apiculate; axillary cymose branches 0–5. |
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. |
Cyathia | peduncle 0–0.5 mm. |
peduncle 0.5–1 mm. |
Euphorbia crenulata |
Euphorbia commutata |
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Phenology | Flowering and fruiting spring–summer. | Flowering and fruiting spring–summer. |
Habitat | Conifer, oak, and mixed forests, coastal scrub, grasslands, barrens and outcrops, roadsides. | Bottomland and upland forests, bluffs and ledges, stream banks, glades, rarely fen margins. |
Elevation | 30–1800 m. (100–5900 ft.) | 50–1000 m. (200–3300 ft.) |
Distribution |
CA; CO; NM; OR
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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 crenulata is most common in the central valleys of California and southern Oregon; it occurs disjunctly in southwestern Colorado and northwestern New Mexico. Previous reports from Arizona are based on misidentified specimens. Euphorbia crenulata is closely related to E. commutata. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 12, p. 301. | FNA vol. 12, p. 300. |
Parent taxa | Euphorbiaceae > Euphorbia > subg. Esula | Euphorbiaceae > Euphorbia > subg. Esula |
Sibling taxa | ||
Synonyms | Tithymalus crenulatus | Galarhoeus austrinus, G. commutatus, Tithymalus commutatus |
Name authority | Engelmann: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 192. (1859) | Engelmann: in A. Gray, Manual ed. 2, 389. (1856) |
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