Euphorbia crenulata |
Euphorbia cordifolia |
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Chinese caps, western wood spurge |
heartleaf sandmat |
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Habit | Herbs, usually biennial, occasionally annual, with taproot. | Herbs, annual, with taproot. |
Stems | erect, sometimes decumbent at base, unbranched or branched, 12–40 cm, glabrous. |
prostrate, occasionally mat-forming, 10–43 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. |
opposite; stipules usually distinct, occasionally connate at base, filiform, 1–1.2(–2.8) mm, usually glabrous, rarely pilose; petiole 0.4–1 mm, usually glabrous; blade ovate to oblong, 4.4–12 × 2.6–7.6 mm, base asymmetric, cordate to rounded, margins entire, apex rounded to mucronulate, surfaces glabrous; only midvein conspicuous. |
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, 1–1.3 × 1–1.3 mm, glabrous; glands 4, yellowish to pink, elliptic, 0.3–0.5 × 0.5–1 mm; appendages whitish to pink, sometimes drying red, elliptic to ovoid, 1.1–1.5 × 1.2–1.9 mm, distal margin entire, retuse, or erose. |
Staminate flowers | 11–18. |
5–40. |
Pistillate flowers | ovary glabrous; styles 0.9–1.4 mm, 2-fid. |
ovary glabrous; styles 0.5–0.8 mm, 2-fid nearly entire length. |
Capsules | subovoid, 2.5–3 × 3.5–4 mm, 3-lobed; cocci rounded, smooth or puncticulate, glabrous; columella 1.9–2.3 mm. |
ovoid, 2–3 mm diam., glabrous; columella 1.2–2.7 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. |
gray or tan with dark brown mottling, ovoid, bluntly 3–4-angled in cross section, 1.8–2.1 × 1.2–1.4 mm, smooth to rugose. |
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. |
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Cyathia | peduncle 0–0.5 mm. |
solitary at distal nodes; peduncle 0.9–3 mm. |
Euphorbia crenulata |
Euphorbia cordifolia |
|
Phenology | Flowering and fruiting spring–summer. | Flowering and fruiting summer–fall. |
Habitat | Conifer, oak, and mixed forests, coastal scrub, grasslands, barrens and outcrops, roadsides. | Xeric oak-pine scrub, pine-barrens, sand barrens, sandy stream banks. |
Elevation | 30–1800 m. (100–5900 ft.) | 0–200 m. (0–700 ft.) |
Distribution |
CA; CO; NM; OR
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AL; AR; FL; GA; LA; MS; NC; OK; SC; TX
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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.) |
Euphorbia cordifolia is easily identified by its cordate to rounded leaf base and distinctive filiform stipules. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 301. | FNA vol. 12, p. 265. |
Parent taxa | Euphorbiaceae > Euphorbia > subg. Esula | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | Tithymalus crenulatus | Chamaesyce cordifolia |
Name authority | Engelmann: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 192. (1859) | Elliott: Sketch. Bot. S. Carolina 2: 656. (1824) |
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