Euphorbia agraria |
Euphorbia macropus |
|
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urban spurge |
Huachuca Mountain spurge |
|
Habit | Herbs, perennial, with slender, spreading rootstock. | Herbs, perennial, with thick, globose to elongated tubers, 2–8 cm. |
Stems | erect or ascending, unbranched or branched, 30–90 cm, glabrous. |
erect to ascending, branched, 10–45(–60) cm, glabrous, puberulent, or densely hirsute to setose, often with 2-layered indumentum of long hairs intermixed with short hairs. |
Leaves | petiole absent; blade oblong-elliptic, 20–65 × 9–20 mm, base truncate to auriculate, margins entire, apex obtuse to rounded, surfaces glabrous; venation conspicuously pinnate, midvein prominent. |
usually opposite, occasionally whorled distally, or rarely with 1–2 alternate leaves; stipules 0.1–0.2 mm; petiole 0–18 mm, hirsute, sericeous, or strigose; blade linear to ovate or almost orbiculate, 6–54 × 2–19 mm, base rounded to attenuate, margins entire, occasionally ciliate with stiff recurved hairs, apex acute to obtuse, surfaces usually hirsute, sericeous, or strigose, occasionally glabrous adaxially; venation conspicuous. |
Involucre | campanulate, 2.2–3 × 1.8–2 mm, glabrous; glands 4, crescent-shaped; 0.6–1 × 1–2 mm; horns slightly divergent to convergent, 0.1–0.2 mm. |
obconic to campanulate, 1.1–1.4 × 0.5–1.5 mm, glabrous or strigillose; glands 4–5, greenish, oblong, 0.2 × 0.4–0.5 mm; appendages usually yellowish or green, rarely dark purple, ovate, flabellate, semiorbiculate, or oblong, 0.3–0.9 × 0.4–1.1 mm, usually entire. |
Staminate flowers | 15–20. |
10–15. |
Pistillate flowers | ovary glabrous; styles 1.2–2 mm, 2-fid. |
ovary glabrous, sericeous, or strigillose; styles 0.4–0.6 mm, 2-fid 1/2 length. |
Capsules | globose, 2–2.8 × 2.2–2.7 mm, 3-lobed; cocci rounded, smooth except finely granulate toward abaxial line, glabrous; columella 2.1–2.7 mm. |
oblate, 2.3–3 × 3.1–4.2 mm, glabrous, sericeous, or strigillose; columella 1.6–2.1 mm. |
Seeds | gray or whitish, ovoid-oblong, 2–2.1 × 1.2–1.3 mm, smooth; caruncle ± rounded and flattened, 0.8 × 0.6 mm. |
black to light brown, broadly ovoid to subglobose, rounded in cross section, 1.5–2.3 × 1.4–1.8 mm, smooth or with low rounded tubercles; caruncle absent. |
Cyathial | arrangement: terminal pleiochasial branches 8–15, 1–2 times 2-branched; pleiochasial bracts similar in shape but shorter and narrower than distal leaves; dichasial bracts distinct, rhombic to reniform, base obtuse, margins entire, apex obtuse, mucronate; axillary cymose branches 12–23. |
|
Cyathia | peduncle 0–2 mm. |
in weakly-defined terminal dichasia; peduncle 1.4–5.8 mm, glabrous. |
Euphorbia agraria |
Euphorbia macropus |
|
Phenology | Flowering and fruiting spring–summer. | Flowering and fruiting summer–fall. |
Habitat | Grasslands, roadside banks, pastures. | Stream banks and rocky slopes in pine-oak woodlands, sometimes with juniper, Douglas fir-pine forests. |
Elevation | 200–1600 m. (700–5200 ft.) | 1500–2200m. (4900–7200ft.) |
Distribution |
KS; MT; NE; NY; PA; WA; WY; AB; SK; Europe [Introduced in North America]
|
AZ; Mexico; Central America (Guatemala, Honduras) |
Discussion | Euphorbia macropus is a widespread and common Mexican species just barely entering the flora area in southeastern Arizona, where most of the collections are from the Huachuca Mountains. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 12, p. 298. | FNA vol. 12, p. 248. |
Parent taxa | Euphorbiaceae > Euphorbia > subg. Esula | Euphorbiaceae > Euphorbia > sect. Alectoroctonum |
Sibling taxa | ||
Synonyms | Tithymalus agrarius | Anisophyllum macropus, E. biformis, E. plummerae |
Name authority | M. Bieberstein: Fl. Taur.-Caucas. 1: 375. (1808) | (Klotzsch & Garcke) Boissier: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 15(2): 52. (1862) |
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