The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

urban spurge

rattlesnake sandmat, rattlesnake weed, white-margin sandmat or sandwort, whitemargin sandmat

Habit Herbs, perennial, with slender, spreading rootstock. Herbs, perennial, with moderately to strongly thickened rootstock.
Stems

erect or ascending, unbranched or branched, 30–90 cm, glabrous.

prostrate, occasionally mat-forming, frequently rooting at nodes, 10–80 cm, glabrous.

Leaves

petiole absent;

blade oblong-elliptic, 20–65 × 9–20 mm, base truncate to auriculate, margins entire, apex obtuse to rounded, surfaces glabrous;

venation conspicuously pinnate, midvein prominent.

opposite;

stipules connate into conspicuous, deltate or ovate scale, white, 0.4–1(–2) mm, glabrous;

petiole less than 1 mm, glabrous;

blade ovate, oblong or orbiculate, 3–8(–15) × 3–7 mm, base strongly asymmetric, obtuse to hemicordate, margins whitish, entire, apex obtuse, rarely mucronulate, surfaces often with red blotch in center, glabrous; 3-veined from base but usually only midvein conspicuous.

Involucre

campanulate, 2.2–3 × 1.8–2 mm, glabrous;

glands 4, crescent-shaped; 0.6–1 × 1–2 mm;

horns slightly divergent to convergent, 0.1–0.2 mm.

campanulate, 0.8–1.1 × 0.9–2 mm, glabrous;

glands 4, greenish yellow to red, usually oblong to reniform, rarely subcircular, 0.2–0.5 × (0.2–)0.3–0.8 mm;

appendages white to pink, flabellate to oblong, 0.3–1 × 0.6–1.3 mm, distal margin entire or crenulate to erose.

Staminate flowers

15–20.

15–30.

Pistillate flowers

ovary glabrous;

styles 1.2–2 mm, 2-fid.

ovary glabrous;

styles 0.3–0.7 mm, 2-fid nearly entire length.

Capsules

globose, 2–2.8 × 2.2–2.7 mm, 3-lobed;

cocci rounded, smooth except finely granulate toward abaxial line, glabrous;

columella 2.1–2.7 mm.

broadly ovoid, 1.1–2.3 × 1.2–2 mm, glabrous;

columella 1.1–1.6 mm.

Seeds

gray or whitish, ovoid-oblong, 2–2.1 × 1.2–1.3 mm, smooth;

caruncle ± rounded and flattened, 0.8 × 0.6 mm.

white to gray or brownish red, oblong-ovoid, 4-angled in cross section, 1–1.7 × 0.5–0.8 mm, smooth.

Cyathial

arrangement: terminal pleiochasial branches 8–15, 1–2 times 2-branched;

pleiochasial bracts similar in shape but shorter and narrower than distal leaves;

dichasial bracts distinct, rhombic to reniform, base obtuse, margins entire, apex obtuse, mucronate;

axillary cymose branches 12–23.

Cyathia

peduncle 0–2 mm.

solitary at distal nodes;

peduncle 1–4 mm.

Euphorbia agraria

Euphorbia albomarginata

Phenology Flowering and fruiting spring–summer. Flowering and fruiting year-round.
Habitat Grasslands, roadside banks, pastures. Disturbed areas in desert scrub, grasslands, mesquite woodlands, chaparral.
Elevation 200–1600 m. (700–5200 ft.) 0–2300 m. (0–7500 ft.)
Distribution
from FNA
KS; MT; NE; NY; PA; WA; WY; AB; SK; Europe [Introduced in North America]
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CA; CO; NM; NV; OK; TX; UT; Mexico [Introduced in Pacific Islands (Hawaii)]
[WildflowerSearch map]
[BONAP county map]
Discussion

Euphorbia albomarginata is native to northern and central Mexico and the southwestern and south-central United States. The species occurs in a variety of habitats in western North America and in some areas is quite weedy. It has been recorded as a waif in Louisiana.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 12, p. 298. FNA vol. 12, p. 259.
Parent taxa Euphorbiaceae > Euphorbia > subg. Esula Euphorbiaceae > Euphorbia > sect. Anisophyllum
Sibling taxa
E. aaron-rossii, E. abramsiana, E. acuta, E. albomarginata, E. alta, E. angusta, E. antisyphilitica, E. arizonica, E. astyla, E. austrotexana, E. bicolor, E. bifurcata, E. bilobata, E. blodgettii, E. bombensis, E. brachycera, E. capitellata, E. carunculata, E. chaetocalyx, E. chamaesula, E. cinerascens, E. commutata, E. conferta, E. cordifolia, E. corollata, E. crenulata, E. cumulicola, E. cuphosperma, E. curtisii, E. cyathophora, E. cyparissias, E. davidii, E. deltoidea, E. dendroides, E. dentata, E. discoidalis, E. eriantha, E. exigua, E. exserta, E. exstipulata, E. falcata, E. fendleri, E. florida, E. floridana, E. garberi, E. georgiana, E. geyeri, E. glyptosperma, E. golondrina, E. gracillima, E. graminea, E. helioscopia, E. helleri, E. heterophylla, E. hexagona, E. hirta, E. hooveri, E. humistrata, E. hypericifolia, E. hyssopifolia, E. indivisa, E. innocua, E. inundata, E. ipecacuanhae, E. jaegeri, E. jejuna, E. laredana, E. lasiocarpa, E. lata, E. lathyris, E. longicruris, E. lurida, E. macropus, E. maculata, E. marginata, E. meganaesos, E. melanadenia, E. mendezii, E. mercurialina, E. mesembrianthemifolia, E. micromera, E. misera, E. missurica, E. myrsinites, E. nephradenia, E. nutans, E. oblongata, E. ocellata, E. ophthalmica, E. ouachitana, E. parishii, E. parryi, E. pediculifera, E. peplidion, E. peplus, E. perennans, E. pergamena, E. pinetorum, E. platyphyllos, E. platysperma, E. polycarpa, E. polygonifolia, E. polyphylla, E. porteriana, E. prostrata, E. pubentissima, E. purpurea, E. radians, E. rayturneri, E. revoluta, E. roemeriana, E. rosescens, E. schizoloba, E. serpens, E. serpillifolia, E. serrata, E. serrula, E. setiloba, E. simulans, E. spathulata, E. stictospora, E. strictior, E. telephioides, E. terracina, E. tetrapora, E. texana, E. theriaca, E. thymifolia, E. tithymaloides, E. trachysperma, E. trichotoma, E. vallis-mortae, E. velleriflora, E. vermiculata, E. villifera, E. virgata, E. wrightii, E. yaquiana
E. aaron-rossii, E. abramsiana, E. acuta, E. agraria, E. alta, E. angusta, E. antisyphilitica, E. arizonica, E. astyla, E. austrotexana, E. bicolor, E. bifurcata, E. bilobata, E. blodgettii, E. bombensis, E. brachycera, E. capitellata, E. carunculata, E. chaetocalyx, E. chamaesula, E. cinerascens, E. commutata, E. conferta, E. cordifolia, E. corollata, E. crenulata, E. cumulicola, E. cuphosperma, E. curtisii, E. cyathophora, E. cyparissias, E. davidii, E. deltoidea, E. dendroides, E. dentata, E. discoidalis, E. eriantha, E. exigua, E. exserta, E. exstipulata, E. falcata, E. fendleri, E. florida, E. floridana, E. garberi, E. georgiana, E. geyeri, E. glyptosperma, E. golondrina, E. gracillima, E. graminea, E. helioscopia, E. helleri, E. heterophylla, E. hexagona, E. hirta, E. hooveri, E. humistrata, E. hypericifolia, E. hyssopifolia, E. indivisa, E. innocua, E. inundata, E. ipecacuanhae, E. jaegeri, E. jejuna, E. laredana, E. lasiocarpa, E. lata, E. lathyris, E. longicruris, E. lurida, E. macropus, E. maculata, E. marginata, E. meganaesos, E. melanadenia, E. mendezii, E. mercurialina, E. mesembrianthemifolia, E. micromera, E. misera, E. missurica, E. myrsinites, E. nephradenia, E. nutans, E. oblongata, E. ocellata, E. ophthalmica, E. ouachitana, E. parishii, E. parryi, E. pediculifera, E. peplidion, E. peplus, E. perennans, E. pergamena, E. pinetorum, E. platyphyllos, E. platysperma, E. polycarpa, E. polygonifolia, E. polyphylla, E. porteriana, E. prostrata, E. pubentissima, E. purpurea, E. radians, E. rayturneri, E. revoluta, E. roemeriana, E. rosescens, E. schizoloba, E. serpens, E. serpillifolia, E. serrata, E. serrula, E. setiloba, E. simulans, E. spathulata, E. stictospora, E. strictior, E. telephioides, E. terracina, E. tetrapora, E. texana, E. theriaca, E. thymifolia, E. tithymaloides, E. trachysperma, E. trichotoma, E. vallis-mortae, E. velleriflora, E. vermiculata, E. villifera, E. virgata, E. wrightii, E. yaquiana
Synonyms Tithymalus agrarius Chamaesyce albomarginata
Name authority M. Bieberstein: Fl. Taur.-Caucas. 1: 375. (1808) Torrey & A. Gray: in War Department [U.S.], Pacif. Railr. Rep. 2(4): 174. (1857)
Web links