Euphorbia maculata |
Euphorbia purpurea |
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euphorbe maculée, milk purslane, milk spurge, prostrate spurge, sandmat, spotted sandmat, spotted sandmat or spurge, spotted spurge |
Darlington's glade spurge, glade or Darlington's glade spurge |
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Habit | Herbs, annual, with taproot. | Herbs, perennial, with thick rootstock. |
Stems | usually prostrate, occasionally with ascending tips, often mat-forming, not rooting at nodes, 5–45 cm, densely and evenly short-sericeous to sericeous or villous. |
erect, unbranched, 70–100(–130) cm, glabrous. |
Leaves | opposite; stipules distinct, linear-subulate, sometimes irregularly 2–3-lobed, 1–1.3 mm, sparsely short-sericeous to sericeous or villous; petiole 0.5–1.5 mm, moderately short-sericeous to sericeous or villous; blade oblong-ovate to ovate-elliptic or oblong-elliptic, 4–18 × 2.5–8 mm, base strongly asymmetric, one side usually angled and other ± truncate and expanded into small, rounded auricle, margins serrulate (longer side) or subentire (shorter side), apex rounded or broadly acute, abaxial surface pale grayish green, moderately to densely lanulose to villous, adaxial surface usually with irregular reddish streak along midvein, glabrate or with sparse, long, slender hairs; palmately veined at base, pinnate distally. |
petiole 0–2 mm; blade lance-oblong to oblanceolate-oblong, 50–100 × 13–30 mm, base attenuate to cuneate, margins entire, apex usually acute, sometimes obtuse to rounded, minutely apiculate, abaxial surface glabrate to sparsely pilose, adaxial surface glabrous; venation pinnate, midvein prominent. |
Involucre | obconic, 0.8–1 × 0.6–0.8 mm, sparsely strigose to short-sericeous; glands 4, green to yellow-green, turning pink with age, usually ± unequal, narrowly oblong to nearly linear, 0.1–0.2 × 0.2–0.5 mm; appendages white to reddish tinged, lunate to oblong, 0.1–0.3 × 0.2–1.5 mm, distal margin crenulate. |
narrowly campanulate, 2.1–3 × 3–4.2 mm, glabrous; glands 5, elliptic to slightly reniform, 1–1.2 × 1.5–2.1 mm; horns absent. |
Staminate flowers | 2–5. |
10–15. |
Pistillate flowers | ovary sericeous; styles 0.3–0.4 mm, 2-fid at apex. |
ovary glabrous; styles 3–3.5 mm, 2-fid. |
Capsules | ovoid, well exserted from involucre at maturity, 1.3–1.5 × 1.2–1.4 mm, sparsely to moderately and evenly sericeous; columella 1–1.2 mm. |
globose, 4.5–5.2 × 6–6.8 mm, 3-lobed; cocci rounded, verrucose, sometimes minutely so, glabrous; columella 4–4.8 mm. |
Seeds | white to light brown, oblong-ovoid, sharply angular in cross section, 1–1.2 × 0.6–0.9 mm, with 3–4 low, transverse ridges that cross angles. |
mottled silver-brown, ovoid-globose, 3–4 × 2.5–3.5 mm, smooth; caruncle subconic, reniform, 0.8–1.1 × 1.4–1.6 mm. |
Cyathia | solitary or in small, cymose clusters at distal nodes or on congested, axillary branches; peduncle 0.1–0.6 mm. |
peduncle 0–1 mm. |
Cyathial | arrangement: terminal pleiochasial branches 3–6, each unbranched or 1–2 times 2-branched, occasionally appearing pendent; pleiochasial bracts lance-ovate, shorter than distal leaves; dichasial bracts distinct, cordate-deltate to reniform, base subcordate, margins entire, apex rounded; axillary cymose branches 0–10. |
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2n | = 28. |
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Euphorbia maculata |
Euphorbia purpurea |
|
Phenology | Flowering and fruiting spring–fall. | Flowering and fruiting spring–fall. |
Habitat | Disturbed areas, fallow fields, gardens, sidewalk cracks, railroads, roadsides. | Dry to moist forests and slopes, rock outcrops, swamps or seeps, especially over calcareous rocks. |
Elevation | 0–1500 m. (0–4900 ft.) | 50–1100 m. (200–3600 ft.) |
Distribution |
AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; BC; NB; NS; ON; PE; QC; Mexico; Central America; South America; West Indies; Eurasia; Africa; Pacific Islands (New Zealand); Australia
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DE; MD; NC; NJ; OH; PA; VA; WV |
Discussion | Euphorbia maculata is a widespread weed in temperate latitudes, and it also occurs in cool climates at higher elevations in the tropics. It is presumed to be native to eastern and central North America, but given its extremely weedy tendencies, it is difficult to know for sure. It spreads readily in association with greenhouse plants and earth-moving activities, and it is notorious for its ability to colonize sidewalk cracks in the summer, even in congested cities. The name E. maculata was misapplied by most earlier botanists (for example, L. C. Wheeler 1941) to plants with ascending stems that are treated here as E. nutans. D. G. Burch (1966) reviewed the sources of data used by Linnaeus in his original description and concluded that the name E. maculata applies to this prostrate-stemmed taxon. For further discussion of the distinctions between E. maculata and the similar 47. E. humistrata, see the treatment of that species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Euphorbia purpurea is primarily an eastern Appalachian forest species, but it also occurs in Adams, Highland, and Pike counties in southern Ohio. It is listed as endangered by Maryland, New Jersey, Ohio, and Pennsylvania, and is in the Center for Plant Conservation's National Collection of Endangered Plants. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 275. | FNA vol. 12, p. 308. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > subg. Esula |
Sibling taxa | ||
Synonyms | Chamaesyce maculata, C. mathewsii, C. supina, C. tracyi, E. supina | Agaloma purpurea, Galarhoeus darlingtonii |
Name authority | Linnaeus: Sp. Pl. 1: 455. (1753) | (Rafinesque) Fernald: Rhodora 34: 25. (1932) |
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