Euphorbia lurida |
Euphorbia rosescens |
|
---|---|---|
woodland spurge |
rosy-pink spurge, scrub spurge |
|
Habit | Herbs, perennial, with thick rootstock. | Herbs, perennial, with thickened rootstock. |
Stems | erect or ascending, unbranched, sometimes sinuous, 5–30 cm, glabrous or sparsely to densely puberulent. |
erect or ascending, 15–45 cm. |
Leaves | petiole 0–1 mm; blade oblanceolate to obovate, 8–20 mm × 3–7 mm, base truncate or cuneate, margins entire, apex obtuse to rounded, minutely mucronate, surfaces puberulent or glabrous; venation inconspicuous, only 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 | cupulate, 2–2.2 × 1.3–1.8 mm, glabrous; glands 4, oblong to broadly ovate, usually truncate, 0.5–0.8 × 1–1.6 mm, margins irregularly crenate to strongly dentate; horns absent or usually divergent or straight, 0.1–0.3 mm, usually slightly longer than, occasionally equaling, teeth on gland margin. |
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 | 10–20. |
25. |
Pistillate flowers | ovary glabrous or puberulent; styles 0.7–1 mm, 2-fid. |
mature gynophore not seen, styles connate 1/2 length, 3.3–3.6 mm. |
Capsules | ovoid, 3.5–4 × 4–4.5 mm, 3-lobed; cocci rounded, smooth to slightly rugose, glabrous; columella 3.2–3.5 mm. |
|
Seeds | gray to dark gray, truncate-oblong to truncate-ovoid, 2.8–3 × 1.7–2 mm, irregularly pitted; caruncle conic, 0.6 × 0.7 mm. |
not seen. |
Cyathial | arrangement: terminal pleiochasial branches 3–5, each 1–4 times 2-branched; pleiochasial bracts ovate to broadly ovate or oblanceolate, wider than distal leaves; dichasial bracts distinct, rounded, oblanceolate, or subreniform, base cuneate or obtuse, margins entire, apex obtuse, slightly mucronate; axillary cymose branches 0–4. |
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 0.3–0.9 mm. |
peduncle 3.9–6.8 mm. |
Mature | capsules not seen. |
|
Euphorbia lurida |
Euphorbia rosescens |
|
Phenology | Flowering and fruiting spring–summer. | Flowering and fruiting spring–summer, rarely fall. |
Habitat | Open pine-oak forests, dry slopes and canyons. | Xeric oak and pine scrub, mostly on white sands, disturbed habitats. |
Elevation | 1300–2800 m. (4300–9200 ft.) | 20–50 m. (100–200 ft.) |
Distribution |
AZ; CA; NM; NV; UT; Mexico (Baja California)
|
FL |
Discussion | Euphorbia lurida has been treated as a complex of several taxa in the past, but only a single, broadly-defined species is recognized here. This species is variable in both the pubescence and shape of the bracts subtending the cyathia and also in the degree of crenation of the gland margin. In the northern part of its range, E. lurida appears to intergrade with E. brachycera, and it can be difficult to distinguish these two species in northern Arizona and New Mexico. A report of the species from Sonora, Mexico, based on a single immature collection (V. W. Steinmann and R. S. Felger 1997) has not been verified. (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. 305. | FNA vol. 12, p. 316. |
Parent taxa | Euphorbiaceae > Euphorbia > subg. Esula | Euphorbiaceae > Euphorbia > sect. Nummulariopsis |
Sibling taxa | ||
Synonyms | E. palmeri, E. palmeri var. subpubens, E. subpubens, Tithymalus luridus, T. palmeri, T. subpubens | |
Name authority | Engelmann: in J. C. Ives, Rep. Colorado R. 4: 26. (1861) | E. L. Bridges & Orzell: Lundellia 5: 71, fig. 4. (2002) |
Web links |