Euphorbia discoidalis |
Euphorbia parishii |
|
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summer spurge |
Parish's sandmat |
|
Habit | Herbs, perennial, with spreading rootstock. | Herbs or subshrubs, perennial, with thickened and often woody rootstock. |
Stems | erect or ascending, unbranched, solitary or few, previous year's dead stems not persistent, 45–70 cm, usually densely puberulent to sericeous, rarely glabrous. |
prostrate, sometimes forming dense mounds, 10–50 cm, glabrous. |
Leaves | alternate; stipules to 0.1 mm; petiole (0–)1–2 mm (or absent), densely puberulent; blade usually linear, rarely ovate, 25–55 × 1.5–4 mm, base cuneate, margins entire, revolute, apex rounded, abaxial surface glabrous or puberulent to sericeous, adaxial surface glabrous; venation often obscure on smaller leaves, midvein conspicuous. |
opposite; stipules distinct, subulate-filiform, 0.3–0.9 mm, pilose; petiole 0.3–1.2 mm, glabrous; blade usually ovate, rarely oblong, 2–7 × 1–5 mm, base usually asymmetric, rounded to hemicordate, margins entire, apex usually obtuse, rarely acute, surfaces glabrous; only midvein conspicuous. |
Involucre | campanulate, 1.2–1.4 × 1.2–2 mm, sparsely to densely puberulent; glands 5, green, reniform, 0.2–0.3 × 0.5–0.6 mm; appendages white, orbiculate to oblong, (0.5–)1–1.7 × 1–1.5 mm, entire. |
obconic to campanulate, 1–1.4 × 0.9–1.3 mm, glabrous except for pilose lobes; glands 4, pink to maroon, circular, 0.3–0.4 × 0.3–0.4 mm; appendages absent. |
Staminate flowers | 20–25. |
40–50. |
Pistillate flowers | ovary glabrous or sparsely strigose; styles 0.5–1.1 mm, 2-fid at apex to 1/2 length. |
ovary glabrous; styles 0.3–0.6 mm, 2-fid 1/2 length. |
Capsules | globose, 1.8–3 × 2.5–4.8 mm, glabrous or sparsely strigose; columella 2.3–2.5 mm. |
ovoid to oblate-ovoid, 1.6–1.7 × 1.6–1.9 mm, glabrous; columella 1.2–1.5 mm. |
Seeds | light gray, ovoid, 2 × 1.2–1.3 mm, smooth or with few, very shallow depressions; caruncle absent. |
whitish to light brown, ovoid, 4-angled in cross section, 1.2–1.4 × 0.6–0.8 mm, rugose or with indistinct, irregular, low transverse ridges. |
Cyathia | in terminal pleiochasia; peduncle 5–15 mm, filiform, glabrous or very sparsely puberulent to sericeous. |
solitary at distal nodes; peduncle 0.1–0.6(–2.2) mm. |
Euphorbia discoidalis |
Euphorbia parishii |
|
Phenology | Flowering and fruiting late spring–fall. | Flowering and fruiting fall–summer. |
Habitat | Sand hills, pine savannas, woodland borders, open fields with sandy soils. | Desert scrub, often with creosote bush, disturbed roadsides, rocky soils. |
Elevation | 0–150 m. (0–500 ft.) | -90–600 m. (-300–2000 ft.) |
Distribution |
AL; FL; GA; LA; MS; TX
|
CA; NV |
Discussion | M. J. Huft (1979) remarked that Euphorbia discoidalis is uncommon west of Alabama and referred many narrow-leaved specimens from Louisiana and Texas to E. corollata. K. R. Park (1998) included them in an expanded E. discoidalis, and that is followed here. The western populations can be distinguished from E. corollata by their shorter involucral gland appendages and revolute leaf margins. Further study of these western populations is warranted. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Euphorbia parishii is common in the Death Valley region of southern California, where it is often encountered well below sea level. The species is frequently confused with E. micromera and E. polycarpa but differs from the former in being a more robust plant with larger cyathia and from the latter in lacking involucral gland appendages. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 245. | FNA vol. 12, p. 280. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Alectoroctonum | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | Tithymalopsis discoidalis | Chamaesyce parishii, E. polycarpa var. parishii |
Name authority | Chapman: Fl. South. U.S., 401. (1860) | Greene: Bull. Calif. Acad. Sci. 2: 56. (1886) |
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