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creeping spurge, Matted sandmat, Matted spurge, round-leafed spurge

red-gland spurge, squaw sandmat

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

prostrate, frequently mat-forming and rooting at nodes, 15–50 cm, glabrous.

ascending to erect, 5–20 cm, sericeous to appressed-villous.

Leaves

opposite;

stipules connate into conspicuous, deltate scale, white to pink, membranaceous, 0.5–1(–1.2) mm, glabrous;

petiole less than 1 mm, glabrous;

blade ovate, oblong or orbiculate, 2–7(–9) × 2–6 mm, base asymmetric, rounded to subcordate, margins entire, apex rounded, surfaces without red blotch, glabrous; usually only midvein conspicuous.

opposite;

stipules distinct (lower side) and connate (upper side), linear, 0.5–1 mm, densely pilose;

petiole 0.8–1.5 mm, tomentose;

blade ovate, 1.2–5 × 0.8–2.9 mm, base asymmetric, hemicordate, margins entire, apex rounded to acute, surfaces tomentose;

venation inconspicuous.

Involucre

campanulate to turbinate, 0.3–0.7(–1) × 0.4–0.6 mm, glabrous;

glands 4, yellow, oblong, 0.1 × 0.2 mm;

appendages white to pinkish, equal, forming narrow rim at edge of gland, 0.1–0.2 × 0.2–0.3 mm, distal margin entire or crenulate.

campanulate, 0.6–1.1 × 0.7–1 mm, tomentose;

glands 4, deep red to purple, elliptic, 0.3–0.4 × 0.4–0.7 mm;

appendages white or becoming pink with age, oblong to flabellate, 0.4–0.7(–1) × 0.7–1.2 mm, distal margin entire or erose.

Staminate flowers

5–10.

45–80.

Pistillate flowers

ovary glabrous;

styles 0.2 mm, 2-fid 1/2 to nearly entire length.

ovary tomentose, styles 0.5–0.8 mm, 2-fid nearly entire length.

Capsules

broadly ovoid, oblate, or subglobose, 1.3–1.4 × 1.3–1.7 mm, glabrous;

columella (0.9–)1–1.2 mm.

ovoid, 1.4–1.8 × 1.4–1.7 mm, tomentose;

columella 1.2–1.5 mm.

Seeds

white to gray or light pink, ovoid, bluntly 3–4-angled in cross section, 0.7–1.1 × 0.4–0.7 mm, smooth.

gray to tan, oblong, 4-angled in cross section, 1–1.2 × 0.4–0.6 mm, smooth to wrinkled or alveolate.

Cyathia

solitary at distal nodes;

peduncle 0.5–1(–2.5) mm.

solitary at distal nodes;

peduncle (0.6–)1.4–1.9 mm.

Euphorbia serpens

Euphorbia melanadenia

Phenology Flowering and fruiting year-round (in warmer areas) or summer (in temperate regions). Flowering and fruiting year-round.
Habitat Mostly sandy or well-drained soils, desert scrub, coastal scrub, chaparral, oak and juniper woodlands, sand dunes, riparian forests, mesquite grasslands, prairies, coniferous and deciduous hardwood forests, disturbed areas. Rocky slopes, river washes, dry to wet soils.
Elevation 0–2000 m. (0–6600 ft.) 400–1400 m. (1300–4600 ft.)
Distribution
from FNA
AL; AR; AZ; CA; CO; FL; GA; IA; IL; IN; KS; KY; LA; MI; MO; MS; MT; ND; NE; NJ; NM; OH; OK; PA; SD; TN; TX; UT; VT; WY; ON; SK; Mexico; Central America; South America; West Indies; Bermuda [Introduced in Europe, Asia, Africa, Australia]
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CA; Mexico (Baja California, Sonora)
[WildflowerSearch map]
[BONAP county map]
Discussion

Euphorbia serpens is one of the most widespread species of the genus in the New World. While it may be indigenous to a portion of the flora area, probably in the warmer, southern part of its range, it is weedy and has likely been introduced in many parts of the flora area, such as Canada and the eastern United States. It is also widely distributed in the Old World, where it is certainly introduced. The strictly prostrate habit with stems rooting at the nodes is characteristic. Euphorbia serpens is often confused with E. albomarginata, a species distributed in the southwestern United States; in addition to the features mentioned in the key, an easy and reliable way to distinguish between them is by the size of the involucral gland appendages: those of E. albomarginata are conspicuous to the naked eye, whereas those of E. serpens are inconspicuous.

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

Euphorbia melanadenia is similar in appearance to E. cinerascens, but E. melanadenia has conspicuous involucral gland appendages whereas E. cinerascens has inconspicuous appendages or lacks them entirely. Euphorbia melanadenia occurs in Arizona and southern California, whereas E. cinerascens is found only in southern and western Texas.

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

Source FNA vol. 12, p. 286. FNA vol. 12, p. 276.
Parent taxa Euphorbiaceae > Euphorbia > sect. Anisophyllum Euphorbiaceae > Euphorbia > sect. Anisophyllum
Sibling taxa
E. aaron-rossii, E. abramsiana, E. acuta, E. agraria, 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. 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. 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. 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 Chamaesyce serpens Chamaesyce melanadenia
Name authority Kunth: in A. von Humboldt et al., Nov. Gen. Sp. 2(fol.): 41; 2(qto.): 52. (1817) Torrey: in War Department [U.S.], Pacif. Railr. Rep. 4(5): 135. (1857)
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