Euphorbia capitellata |
Euphorbia telephioides |
|
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capitate sandmat, head sandmat, head spurge |
telephus spurge |
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Habit | Herbs, annual or perennial, with slender to thick and woody rootstock. | Herbs, perennial, with thickened rootstock. |
Stems | usually ascending (but ranging from decumbent to erect), 15–50 cm, glabrous, strigillose, or pilose. |
erect or ascending, 20–30 cm. |
Leaves | opposite; stipules distinct, filiform or divided into 2–3 subulate-filiform segments, without dark, circular glands at base, 0.6–1.5 mm, pilose; petioles 0.6–1.3 mm, glabrous, pilose, or strigillose; blade ovate to narrowly ovate, 4–19 × 2–8 mm, base asymmetric, one side strongly cordate, other side rounded to slightly cordate, margins entire or serrulate (commonly nearly entire with few scattered teeth, often slightly thickened), apex acute, surfaces often with red spot in center, glabrous, pilose, or strigillose; weakly 3-veined from base, usually only midvein conspicuous. |
petiole usually absent or indistinct, occasionally to 5.5 mm, blade elliptic or obovate, 31–60 × 7–32 mm, thick and fleshy, base attenuate or cuneate, apex acute, obtuse, or mucronate; venation pinnate with 8–13 lateral veins, these sometimes obscure and only midvein evident. |
Involucre | narrowly obconic to narrowly campanulate, 0.8–1.6 × 0.7–1.3 mm, glabrous or pilose; glands 4, yellow-green to pink or maroon, circular to oblong, 0.2–0.4 × 0.2–0.5 mm; appendages white to light pink, oblong to reniform or flabellate, 0.2–1.1 × 0.5–1.7 mm, surfaces glabrous, distal margin entire. |
campanulate, 1.3–2.3 × 1.6–2.5 mm, lobes ovate to oblong, 0.5–0.7 mm, ciliate; glands purple-red, oblong to trapezoidal, 0.5–0.7 × 0.8–1.2 mm, distal margins entire or crenulate. |
Staminate flowers | 25–40. |
25–30. |
Pistillate flowers | ovary glabrous or pilose; styles 0.4–0.6 mm, 2-fid entire length. |
gynophore exserted 1.9–3.2 mm, calyxlike lobes triangular, 0.2–0.7 mm; styles connate 1/4 length, 1.3–1.5 mm. |
Capsules | ovoid to oblate, 1.3–1.9 × 1.4–2.1 mm, glabrous or pilose; columella 1.1–1.7 mm. |
ovoid-oblate, 5.2–5.6 × 6.6–8.3 mm, 3-lobed; columella 3.9–4.1 mm. |
Seeds | pink to pinkish gray, narrowly ovoid to narrowly ovoid-oblong, 4-angled or weakly 3-angled in cross section, 0.9–1.5 × 0.5–0.7 mm, irregularly dimpled, sometimes also with faint transverse ridges that do not pass through abaxial keel. |
blackish to dark brown, ovoid to globose-ovoid, circular in cross section, 3.2–3.5 × 2.6–3.1 mm, smooth, base rounded to flattened, apex rounded, occasionally with low point. |
Cyathia | in dense, terminal capitate glomerules, with reduced, bractlike leaves subtending cyathia, at tips of main stems and short, leafy, axillary branches; peduncle 0.1–1.2 mm. |
peduncle 3–9.2 mm (often exceeding subcyathial leaves). |
Cyathial | arrangement: terminal pleiochasial branches (2–)3, 5–13 cm, 3–7 times 2-branched; pleiochasial bracts ovate to oblong, 17–31 × 8–15 mm, margins entire, apex acute or obtuse; dichasial bracts ovate, 5–19 × 3–9 mm, margins entire, apex acute or obtuse; axillary cymose branches 1–5. |
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2n | = 14. |
|
Euphorbia capitellata |
Euphorbia telephioides |
|
Phenology | Flowering and fruiting year-round in response to sufficient moisture. | Flowering and fruiting spring–fall. |
Habitat | Gravelly washes, rocky slopes, basaltic talus, disturbed roadsides, primarily desert scrub, desert grasslands, riparian forests, rarely oak-juniper woodlands. | Scrubby pine flatwoods, grasslands, disturbed areas, often in sandy soils. |
Elevation | 600–1600 m. (2000–5200 ft.) | 0–20 m. (0–100 ft.) |
Distribution |
AZ; NM; TX; Mexico (Baja California, Baja California Sur, Chihuahua, Coahuila, Sinaloa, Sonora)
|
FL |
Discussion | Euphorbia capitellata is a characteristic herb in the Sonoran Desert of southern Arizona, ranging east to extreme southwestern Texas. During peak flowering, plants are attractive due to the dense clusters of cyathia with well-developed involucral gland appendages. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Euphorbia telephioides, federally listed as threatened, is known only from Bay, Franklin, and Gulf counties in the Apalachicola region of the east-central Florida panhandle. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 262. | FNA vol. 12, p. 316. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > sect. Nummulariopsis |
Sibling taxa | ||
Synonyms | Chamaesyce capitellata, C. pycnanthema, E. pycnanthema | Galarhoeus telephioides |
Name authority | Engelmann: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 188. (1859) | Chapman: Fl. South. U.S., 402. (1860) |
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