Euphorbia commutata |
Euphorbia trichotoma |
|
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tinted euphorbia, tinted woodland spurge |
sand-dune spurge |
|
Habit | Herbs, usually biennial, occasionally annual, with taproot. | Herbs, perennial, with thick rootstock. |
Stems | erect or ascending, decumbent and often branched near base, 10–40 cm, glabrous. |
erect, branched, 15–40 cm, glabrous. |
Leaves | 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. |
petiole absent; blade obovate to oblanceolate, 5–20 × 2–7 mm, base broadly attenuate, margins entire, apex acute to obtuse, surfaces glabrous; venation pinnate, very obscure, midvein prominent. |
Involucre | 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. |
hemispheric, 1–1.5 × 1.4–2 mm, glabrous; glands 5, elliptic to slightly crescent-shaped, 0.4–0.6 × 0.9–1.1 mm; horns divergent, 0.1–0.2 mm. |
Staminate flowers | 9–15. |
8–10. |
Pistillate flowers | ovary glabrous; styles 0.9–1.3 mm, 2-fid. |
ovary glabrous; styles 0.2–0.4 mm, 2-fid. |
Capsules | ovoid-globose, 2.5–3.2 × 3 mm, slightly lobed; cocci rounded to ± flattened, smooth, glabrous; columella 1.5–2 mm. |
depressed-ovoid, 1.1–1.5 × 2–3 mm, strongly 3-lobed; cocci rounded, minutely papillate, sometimes appearing smooth, glabrous; columella 1.6–1.9 mm. |
Seeds | 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. |
white, ovoid-globose, 1.8–2 × 1.6–1.8 mm, smooth; caruncle ± rounded and flattened, 0.3 × 0.3 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. |
arrangement: terminal pleiochasial branches 3, each usually 1–2 times 3-branched, sometimes unbranched; pleiochasial bracts similar in shape and size to distal leaves, alternate; dichasial bracts distinct, obovate to oblanceolate, base broadly attenuate, margins entire, apex acute to obtuse; axillary cymose branches 0. |
Cyathia | peduncle 0.5–1 mm. |
peduncle 0.7–1 mm. |
Euphorbia commutata |
Euphorbia trichotoma |
|
Phenology | Flowering and fruiting spring–summer. | Flowering and fruiting year-round (primarily spring–summer). |
Habitat | Bottomland and upland forests, bluffs and ledges, stream banks, glades, rarely fen margins. | Coastal beaches, sand dunes, thickets. |
Elevation | 50–1000 m. (200–3300 ft.) | 0–10 m. (0–0 ft.) |
Distribution |
AL; AR; FL; GA; IA; IL; IN; KY; LA; MD; MI; MO; MS; NC; OH; OK; PA; SC; TN; VA; WI; WV; ON
|
FL; Mexico; Central America; West Indies |
Discussion | Euphorbia trichotoma is found in coastal peninsular Florida from Hillsborough County south to Key West. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 12, p. 300. | FNA vol. 12, p. 311. |
Parent taxa | Euphorbiaceae > Euphorbia > subg. Esula | Euphorbiaceae > Euphorbia > subg. Esula |
Sibling taxa | ||
Synonyms | Galarhoeus austrinus, G. commutatus, Tithymalus commutatus | Galarhoeus trichotomus, Tithymalus trichotomus |
Name authority | Engelmann: in A. Gray, Manual ed. 2, 389. (1856) | Kunth: in A. von Humboldt et al., Nov. Gen. Sp. 2(fol.): 48; 2(qto.): 60. (1817) |
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