Euphorbia alta |
Euphorbia rosescens |
|
---|---|---|
giant spurge, roughpod spurge, tall spurge, warty spurge |
rosy-pink spurge, scrub spurge |
|
Habit | Herbs, annual or biennial, with taproot. | Herbs, perennial, with thickened rootstock. |
Stems | erect, branched, 20–60 cm, glabrous. |
erect or ascending, 15–45 cm. |
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 indistinct, blade narrowly elliptic, elliptic, narrowly oblong, or obovate, 25–55 × 5–21 mm, thick and fleshy, base attenuate, apex acute or mucronulate; only midvein evident. |
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. |
obconic to campanulate, 2.4–3.6 × 2.5–3.6 mm, lobes ovate to oblong, 0.7–1 mm, ciliate; glands green to yellow, oblong or trapezoidal, 0.9–1.7 × 1.9–2.5 mm, distal margins crenulate-erose. |
Staminate flowers | 5–10. |
25. |
Pistillate flowers | ovary glabrous; styles 0.5–0.9 mm, 2-fid. |
mature gynophore not seen, styles connate 1/2 length, 3.3–3.6 mm. |
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. |
|
Seeds | purple-black, ovoid, 1.6–2 × 1.3–1.7 mm, reticulate and areolate; caruncle reniform, flat, 0.5 × 0.7 mm. |
not seen. |
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 3, 7–16 cm, 4–7 times 2-branched; pleiochasial bracts ovate to oblong, 17–31 × 13–14 mm, margins entire, apex acute, often also mucronulate; dichasial bracts ovate or lanceolate, 6–18 × 8–12 mm, margins entire, apex acute, often also mucronate; axillary cymose branches 1–2. |
Cyathia | peduncle 0.5–1 mm. |
peduncle 3.9–6.8 mm. |
Mature | capsules not seen. |
|
Euphorbia alta |
Euphorbia rosescens |
|
Phenology | Flowering and fruiting summer. | Flowering and fruiting spring–summer, rarely fall. |
Habitat | Montane pine-oak and mixed conifer forests, disturbed roadsides, logged areas. | Xeric oak and pine scrub, mostly on white sands, disturbed habitats. |
Elevation | 1500–3000 m. (4900–9800 ft.) | 20–50 m. (100–200 ft.) |
Distribution |
AZ; NM; Mexico
|
FL |
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 rosescens is a narrow-endemic, gap-specialist known only from the southern portion of the Lake Wales Ridge in Highlands County. Based on leaf characteristics, it appears to be most similar to E. telephioides. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 298. | FNA vol. 12, p. 316. |
Parent taxa | Euphorbiaceae > Euphorbia > subg. Esula | Euphorbiaceae > Euphorbia > sect. Nummulariopsis |
Sibling taxa | ||
Synonyms | Tithymalus altus | |
Name authority | Norton: N. Amer. Euphorbia, 24, plate 24. (1899) | E. L. Bridges & Orzell: Lundellia 5: 71, fig. 4. (2002) |
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