Euphorbia fendleri |
Euphorbia porteriana |
|
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Fendler's sandmat |
Porter's sandmat |
|
Habit | Herbs, perennial, with woody, thickened taproot. | Herbs, usually annual, sometimes perennial, with slender to occasionally thickened taproot, 5 mm diam.. |
Stems | usually prostrate, decumbent, or ascending, very rarely erect, often densely clustered from top of woody crown, 5–12 cm, glabrous. |
erect to ascending, sometimes slightly woody at base, not mat-forming, 15–60 cm, usually glabrous, young branches rarely very sparsely short pubescent. |
Leaves | usually opposite, rarely whorled; stipules distinct, narrowly linear, 0.5–1 mm, glabrous; petiole 0.5–1 mm, glabrous; blade usually orbiculate to ovate, rarely almost lanceolate, 3–8 × 2.5–7 mm, base slightly asymmetric, slightly cordate to rounded or obtuse, margins entire, apex rounded to obtuse, surfaces glabrous; obscurely 3–5-veined from base, only midvein conspicuous. |
opposite; stipules usually distinct, occasionally connate basally, triangular, entire or 2–4 parted, apically ciliate, 0.3–0.4 mm, usually glabrous, rarely very sparsely short pubescent; petiole 0.5–1.5 mm, usually glabrous, rarely very sparsely short pubescent; blade ovate, oval, elliptic, oblong-elliptic, or linear-elliptic, 4–12 × 1–7 mm, base asymmetric, rounded or subcordate, margins usually entire, rarely sparsely serrate, apex obtuse to acute, sometimes mucronate, surfaces abaxially often purple or red, adaxially green, usually glabrous, rarely very sparsely short pubescent; 3-veined from base, only midvein conspicuous. |
Involucre | campanulate to turbinate or broadly cupulate, 1.1–1.7 × 1.2–1.8 mm, glabrous; glands 4, yellow-green to reddish, elliptic to oblong, 0.2–0.5 × 0.4–0.9 mm; appendages absent or white, rarely pink, often unequal, lunate to flabellate or sometimes forming crenate margin along gland, (0–)0.1–0.6 × (0–)0.5–1.5 mm, distal margin entire or toothed. |
turbinate to campanulate, 0.7–1 × 0.8–1 mm, usually glabrous, rarely very sparsely short pubescent; glands 4, brown, slightly concave, elliptic-oblong, 0.1–0.2 × 0.3–0.6 mm; appendages white or pink to dark red, usually oblong or flabellate, occasionally rudimentary and forming narrow rim at edge of gland, (0–)0.1–0.2 × 0.4–1 mm, distal margin entire or crenulate. |
Staminate flowers | 25–35. |
8–14. |
Pistillate flowers | ovary glabrous; styles 0.3–0.4 mm, 2-fid 1/2 length. |
ovary glabrous, subtended by triangular calyxlike structure; styles 0.4–0.6 mm, 2-fid 1/2 length. |
Capsules | depressed-globose, 2–2.4 × 2.2–2.5 mm, glabrous; columella 1.7–2.1 mm. |
broadly ovoid, 1–1.5 × 1.7–2.1 mm, glabrous; columella 1–1.4 mm. |
Seeds | white, ovoid-pyramidal, prominently 4-angled in cross section, 1.7–2 × 1–1.2 mm, smooth to slightly wrinkled. |
reddish brown, ovoid, 4-angled in cross section, 0.7–1 × 0.6–0.7 mm, smooth or obscurely wrinkled. |
Cyathia | solitary at distal nodes; peduncle 0.7–1.2 mm. |
solitary at distal nodes; peduncle 0.5–1.1 mm. |
2n | = 28. |
|
Euphorbia fendleri |
Euphorbia porteriana |
|
Phenology | Flowering and fruiting spring–fall. | Flowering and fruiting year-round. |
Habitat | Mountain slopes, desert scrub, pinyon-juniper woodlands, hills, canyons, grasslands, washes, roadsides, dry crevices in limestone, often in gravel and sand. | Pine rocklands, coastal scrub, open hammocks. |
Elevation | 500–2600 m. (1600–8500 ft.) | 0–10 m. (0–0 ft.) |
Distribution |
AZ; CA; CO; KS; NE; NM; NV; OK; SD; TX; UT; WY; Mexico (Coahuila)
|
FL |
Discussion | Euphorbia fendleri is similar to E. chaetocalyx and may sometimes be confused with that species. Its prostrate to decumbent or ascending stems and small, ovate to orbiculate leaves distinguish it from E. chaetocalyx. Some authors have used the presence or absence and shape of the involucral gland appendages to help separate E. fendleri from E. chaetocalyx, but those characters appear highly variable and of little taxonomic utility; somewhat intermediate individuals occur in western Arizona, New Mexico, and Texas. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Euphorbia porteriana is found in Miami-Dade County and on Big Pine Key, Monroe County. This species is closely related to E. blodgettii, E. garberi, and E. serpens. The capsules of E. porteriana are almost always completely glabrous, but the authors have seen three specimens with just a few scattered hairs on the keels. A. Herndon (1993) synonymized E. porteriana var. keyensis under E. garberi because of its uniformly hairy capsules, and that treatment is followed here. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 267. | FNA vol. 12, p. 285. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | Chamaesyce fendleri | Chamaesyce porteriana, C. porteriana var. scoparia, C. scoparia |
Name authority | Torrey & A. Gray: in War Department [U.S.], Pacif. Railr. Rep. 2(4): 175. (1857) | (Small) Oudejans: Phytologia 67: 48. (1989) |
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