Euphorbia agraria |
Euphorbia strictior |
|
---|---|---|
urban spurge |
panhandle spurge |
|
Habit | Herbs, perennial, with slender, spreading rootstock. | Herbs, perennial, with cylindric rootstock. |
Stems | erect or ascending, unbranched or branched, 30–90 cm, glabrous. |
erect, branched, densely clumped, previous year’s dead stems often persistent, 30–70 cm, glabrous. |
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. |
alternate, persisting, spreading or ascending; stipules to 0.1 mm; petiole absent; blade linear to narrowly oblanceolate, (20–)40–70 × (2–)4–5 mm, base narrowly cuneate, margins entire, apex broadly acute, surfaces glabrous; venation obscure, only midvein conspicuous on wider leaves. |
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. |
campanulate or hemispheric, 1.2–2.4 × 2.2–3.2 mm, pilose; glands 5, green, broadly elliptic, 0.7–0.8 × 1.3–1.6 mm; appendages white, forming narrow rim around distal margin of gland, 0.2 × 1.5–1.8 mm, entire or erose. |
Staminate flowers | 15–20. |
20–25. |
Pistillate flowers | ovary glabrous; styles 1.2–2 mm, 2-fid. |
ovary strigillose to tomentulose; styles 0.4–0.6 mm, 2-fid at apex. |
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. |
globose, all 3 locules fertile, 3.2–4.5 × 4–6.5 mm, sparsely strigillose; columella 2.5–3.9 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. |
gray-green to gray-brown, ovoid, 3.8 × 3 mm, shallowly and obscurely pitted; 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 terminal dichasia; peduncle (2–)4–12(–18) mm proximal and mid peduncles and cyathia abscising early, sparsely to moderately strigose to sericeous. |
Euphorbia agraria |
Euphorbia strictior |
|
Phenology | Flowering and fruiting spring–summer. | Flowering and fruiting spring–fall. |
Habitat | Grasslands, roadside banks, pastures. | Open grasslands and uplands. |
Elevation | 200–1600 m. (700–5200 ft.) | 900–1400 m. (3000–4600 ft.) |
Distribution |
KS; MT; NE; NY; PA; WA; WY; AB; SK; Europe [Introduced in North America]
|
NM; TX |
Discussion | Euphorbia strictior is confined to a small area of the Texas Panhandle and adjacent New Mexico. The species is closely related to E. aaron-rossii and E. wrightii; it can be distinguished from E. wrightii by its larger stature, shorter and less petaloid involucral gland appendages, and early abscising proximal and mid cyathia and peduncles. Euphorbia strictior also tends to develop all three seeds in the capsule, whereas E. wrightii tends to develop only two. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 12, p. 298. | FNA vol. 12, p. 251. |
Parent taxa | Euphorbiaceae > Euphorbia > subg. Esula | Euphorbiaceae > Euphorbia > sect. Alectoroctonum |
Sibling taxa | ||
Synonyms | Tithymalus agrarius | |
Name authority | M. Bieberstein: Fl. Taur.-Caucas. 1: 375. (1808) | Holzinger: Contr. U.S. Natl. Herb. 1: 214, plate 18. (1892) |
Web links |