Euphorbia alta |
Euphorbia myrsinites |
|
---|---|---|
giant spurge, roughpod spurge, tall spurge, warty spurge |
broad leaf glaucous spurge, donkey tail, myrtle or creeping or blue spurge, myrtle spurge |
|
Habit | Herbs, annual or biennial, with taproot. | Herbs, usually perennial, occasionally biennial, with taproot. |
Stems | erect, branched, 20–60 cm, glabrous. |
erect or semiprostrate, unbranched or branched, 15–40 cm, succulent, glabrous. |
Leaves | petiole 0–1 mm; blade oblong-spatulate, 20–50 × 7–18 mm, base broadly attenuate, margins serrulate, apex rounded to obtuse, surfaces glabrous, ± glaucous; venation pinnate, midvein prominent. |
petiole 0–2 mm; blade obovate, obovate-oblong, lanceolate, orbiculate, or suborbiculate, 2–30 × 3–17 mm, fleshy, base truncate or attenuate, margins entire or finely denticulate, apex acute to obtuse, cuspidate or strongly mucronate, surfaces glabrous; venation and midvein inconspicuous. |
Involucre | narrowly campanulate, 0.8–1.1 × 1.1–1.3 mm, glabrous; glands 4, elliptic, 0.3–0.5 × 0.5–0.7 mm; horns absent. |
campanulate, 2.4–2.6 × 2.3–2.5 mm, glabrous; glands 4, trapezoidal, 1–1.5 × 1.5–2.5 mm; horns divergent, thick, tips rounded, dilated, 0.5–0.9 mm. |
Staminate flowers | 5–10. |
6–12. |
Pistillate flowers | ovary glabrous; styles 0.5–0.9 mm, 2-fid. |
ovary glabrous; styles 2.5–2.8 mm, usually unbranched. |
Capsules | depressed-globose, 2–3 × 2.5–3.5 mm, 3-lobed; cocci rounded, papillate, papillae 0.2–0.5 mm, glabrous; columella 1.5–1.9 mm. |
subglobose, 5–7 × 5–6 mm, unlobed; cocci rounded to subangular, smooth, glabrous; columella 4.5–5 mm. |
Seeds | purple-black, ovoid, 1.6–2 × 1.3–1.7 mm, reticulate and areolate; caruncle reniform, flat, 0.5 × 0.7 mm. |
brownish to grayish, oblong, 2.8–4.5 × 2–3.2 mm, vermiculate-rugose; caruncle substipitate, trapezoidal or mushroom-shaped, 1.3–1.5 × 0.6–0.8 mm. |
Cyathial | arrangement: terminal pleiochasial branches 3, 2–3 times 2-branched; pleiochasial bracts elliptic-oblanceolate to oblong, similar in size to distal leaves; dichasial bracts distinct, broadly ovate to orbiculate/reniform, base obtuse, margins serrulate, apex obtuse to rounded and often mucronulate; axillary cymose branches 6–20(–25). |
arrangement: terminal pleiochasial branches 2–12, each 1–2 times 2-branched; pleiochasial bracts similar in shape and size to distal leaves; dichasial bracts distinct, suborbiculate or reniform, base truncate, margins entire or minutely denticulate, apex obtuse, mucronulate; axillary cymose branches 0–4. |
Cyathia | peduncle 0.5–1 mm. |
peduncle 0.5–1 mm. |
Euphorbia alta |
Euphorbia myrsinites |
|
Phenology | Flowering and fruiting summer. | Flowering and fruiting spring–summer. |
Habitat | Montane pine-oak and mixed conifer forests, disturbed roadsides, logged areas. | Scrub oak communities, open ground near forests, shrub-steppes. |
Elevation | 1500–3000 m. (4900–9800 ft.) | 0–2400 m. (0–7900 ft.) |
Distribution |
AZ; NM; Mexico
|
CA; CO; ID; MT; NM; OR; UT; WA; WY; BC; s Europe; w Asia [Introduced in North America]
|
Discussion | Euphorbia alta is a montane species from southern Arizona, New Mexico, and northern and central Mexico that is very similar to and sometimes difficult to distinguish from E. spathulata. Euphorbia alta tends to be a robust biennial, whereas E. spathulata is strictly annual. The most consistent characteristic to separate these two species is that the ovaries and capsules of E. alta are distinctly papillate, with the papillae rising sharply above the surface, whereas the ovaries and capsules of E. spathulata are merely verrucose, with the protuberances lower and rounded. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Euphorbia myrsinites is cultivated in much of the flora area, where it can tolerate cold winters. In some areas, it can locally escape from cultivation. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 298. | FNA vol. 12, p. 305. |
Parent taxa | Euphorbiaceae > Euphorbia > subg. Esula | Euphorbiaceae > Euphorbia > subg. Esula |
Sibling taxa | ||
Synonyms | Tithymalus altus | Tithymalus myrsinites |
Name authority | Norton: N. Amer. Euphorbia, 24, plate 24. (1899) | Linnaeus: Sp. Pl. 1: 461. (1753) |
Web links |
|