Euphorbia polyphylla |
Euphorbia capitellata |
|
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lesser Florida spurge |
capitate sandmat, head sandmat, head spurge |
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Habit | Herbs, perennial, with spreading rootstock. | Herbs, annual or perennial, with slender to thick and woody rootstock. |
Stems | erect or ascending, branched, solitary, few, or occasionally densely clumped, previous year's dead stems not persistent, 18–33 cm, glabrous. |
usually ascending (but ranging from decumbent to erect), 15–50 cm, glabrous, strigillose, or pilose. |
Leaves | alternate; stipules to 0.1 mm; petiole minute or absent; blade linear to filiform, 10–20 × 0.8–1.5(–4) mm, base cuneate, margins entire, often involute, apex rounded, surfaces glabrous; venation usually obscure, midvein visible at base of wider 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. |
Involucre | campanulate, 1.2–2 × 1.3–1.8 mm, glabrous or strigose on distal extreme; glands 5, red, elliptic, 0.5 × 1 mm; appendages white, orbiculate, 0.5–0.8 × 1.3–1.5 mm, erose. |
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. |
Staminate flowers | 20–25. |
25–40. |
Pistillate flowers | ovary glabrous; styles 0.6–1 mm, 2-fid at apex. |
ovary glabrous or pilose; styles 0.4–0.6 mm, 2-fid entire length. |
Capsules | globose, 2.3–2.8 × 4.3–5.1 mm, glabrous; columella 2.5–3.2 mm. |
ovoid to oblate, 1.3–1.9 × 1.4–2.1 mm, glabrous or pilose; columella 1.1–1.7 mm. |
Seeds | ashy gray, ovoid, 2.9 × 2 mm, with obscure shallow depressions; caruncle absent. |
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. |
Cyathia | in terminal dichasia or pleiochasia; peduncle 2–6 mm (to 20 mm for central cyathium), glabrous. |
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. |
2n | = 14. |
|
Euphorbia polyphylla |
Euphorbia capitellata |
|
Phenology | Flowering and fruiting late spring–late fall. | Flowering and fruiting year-round in response to sufficient moisture. |
Habitat | Open sand and pine savannas. | Gravelly washes, rocky slopes, basaltic talus, disturbed roadsides, primarily desert scrub, desert grasslands, riparian forests, rarely oak-juniper woodlands. |
Elevation | 0–10 m. (0–0 ft.) | 600–1600 m. (2000–5200 ft.) |
Distribution |
FL
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AZ; NM; TX; Mexico (Baja California, Baja California Sur, Chihuahua, Coahuila, Sinaloa, Sonora)
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Discussion | Euphorbia polyphylla is endemic to sandy habitats in the southern half of peninsular Florida. The species has been reported from coastal Louisiana, but whether those plants represent native occurrences or plantings is unclear (R. D. Thomas and C. M. Allen 1993–1998, vol. 2). The Florida populations are here recognized as the only native occurrences. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 12, p. 250. | FNA vol. 12, p. 262. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Alectoroctonum | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | Tithymalopsis polyphylla | Chamaesyce capitellata, C. pycnanthema, E. pycnanthema |
Name authority | Engelmann ex Chapman: Fl. South. U.S. ed. 2, repr. 2, 694. (1892) | Engelmann: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 188. (1859) |
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