FNA: Euphorbia thymifolia vs. Euphorbia revoluta

	Euphorbia thymifolia	Euphorbia revoluta
	gulf sandmat	revolute spurge, threadstem sandmat, threadstem spurge
Habit	Herbs, annual or perennial, with taproot.	Herbs, annual, with slender taproot.
Stems	prostrate, mat-forming, 15–30 cm, strigose to strigose-tomentulose.	erect, 5–25 cm, glabrous.
Leaves	opposite; stipules distinct or slightly connate at base, linear-subulate, entire or slightly parted, 0.9–1.2 mm, strigose-tomentulose; petiole 0.5–1 mm, sparsely strigose-tomentulose; blade broadly elliptic to narrowly oblong or ovate-lanceolate, 3–10 × 1.8–5 mm, base asymmetric, one side usually angled or rounded and the other truncate and expanded into small, rounded auricle, margins serrate (larger leaves) to serrulate (smaller leaves), apex blunt to acute, abaxial surface sparsely tomentulose to glabrate, adaxial surface glabrate; palmately veined at base, pinnate distally.	opposite; stipules distinct, subulate-filiform, entire, 0.5–0.9 mm, glabrous; petiole 0.6–1.1 mm, glabrous; blade linear, 6–27 × 0.6–1.2 mm, base symmetric, attenuate, margins entire, revolute, apex acute, sometimes mucronate, surfaces glabrous; only midvein conspicuous.
Involucre	broadly obconic, becoming distended and distorted by base of partially included capsule, 0.4–0.8 × 0.3–0.5 mm, strigose; glands 4, red, slightly concave, ± unequal, subcircular to broadly oval, 0.1–0.2 × 0.2–0.3 mm; appendages white to pink, usually unequal, occasionally ± equal at distal nodes, elongated toward sinus, sometimes rudimentary, 0.1–0.4 × 0.1–0.3 mm, distal margin entire or crenulate.	obconic to campanulate, 0.7–0.9 × 0.5–0.7 mm, glabrous; glands 4, pink to dark purple, nearly circular to oblong or reniform, 0.1 × 0.1–0.2 mm; appendages white, oblong, nearly circular, ovate, deltate, or forming thin margin around gland, rarely absent, (0–)0.1–0.2 × (0–)0.1–0.3 mm, distal margin entire.
Staminate flowers	3–5.	5–10.
Pistillate flowers	ovary densely strigose; styles 0.4–0.5 mm, 2-fid 1/2 length.	ovary glabrous; styles 0.2–0.3 mm, unbranched.
Capsules	conic to truncate-ovoid, scarcely exserted from involucre, base often remaining inside involucre and splitting one side of it during maturation, 0.9–1.2 × 1–1.2 mm, sparsely to moderately strigose; columella 0.6–1 mm.	ovoid to subglobose, 1.5–1.8 × 1.6–1.8 mm, glabrous; columella 1.1–1.5 mm.
Seeds	white, tan underneath coat, ovoid to narrowly ovoid, sharply 4-angled in cross section, 0.8–0.9 × 0.4–0.6 mm, with 4 low transverse ridges often slightly extending into angles, not sulcate.	whitish, brick red, light gray, or light brown, narrowly to broadly ovoid, 4-angled in cross section, 0.9–1.4 × 0.7–1 mm, nearly smooth, rugulose, with faint transverse ridges, or with 2–3 well-defined transverse ridges separated by shallow depressions.
Cyathia	usually in small, cymose clusters on congested, axillary branches; peduncle (0–)0.1–0.3 mm.	solitary at distal nodes; peduncles absent or to 1.5 mm.

	Euphorbia thymifolia	Euphorbia revoluta
Phenology	Flowering and fruiting midsummer–early fall.	Flowering and fruiting summer–late fall.
Habitat	Disturbed areas, often near salt water.	Desert scrub, sagebrush scrub, juniper woodlands, Joshua tree-pinyon pine woodlands, oak woodlands, grasslands, chaparral, pine-oak forests.
Elevation	0–20 m. (0–100 ft.)	600–2500 m. (2000–8200 ft.)
Distribution	FL; LA; Mexico; South America; West Indies [Introduced in Asia, tropical Africa, Australia] [BONAP county map]	AZ; CA; CO; NM; NV; TX; UT; Mexico (Baja California, Chihuahua, Coahuila, Sonora, Zacatecas) [WildflowerSearch map] [BONAP county map]
Discussion	Euphorbia thymifolia is a widespread tropical and subtropical weed. It is not certain where the species is native, but most likely it originated in the New World and then became widespread in the rest of the tropics. Euphorbia thymifolia is present in the flora area in southern Florida and coastal Louisiana, where it is likely adventive. Euphorbia thymifolia is generally similar to E. maculata but is characterized by its short pistillate pedicels and non-exserted capsules that remain largely enclosed by the involucre and by its unequal involucral gland appendages. (Discussion copyrighted by Flora of North America; reprinted with permission.)	Euphorbia revoluta is a distinctive, easily recognizable species by virtue of the combination of unbranched styles and linear leaves with symmetric bases. The species ranges through northern Mexico into the southwestern United States and is composed of three well-marked, geographically distinct races that can be distinguished by their seeds. The first of these races occurs primarily in pine-oak forest of the Sierra Madre Occidental of Mexico (Chihuahua and Sonora) and barely enters the flora area in the Huachuca Mountains of southeastern Arizona; the seeds are brick red and nearly smooth. The second race is widespread in the Chihuahuan Desert from northern Mexico to southeastern New Mexico and southwestern Texas; its seeds are whitish to light gray and possess two or three well-defined transverse ridges separated by shallow depressions. The third race corresponds to the type collection and is characterized by grayish white to light brown seeds that are rugulose or with faint transverse ridges; it occurs in northwestern Mexico (Baja California and Sonora) and throughout the arid southwestern United States. It is probable that further study will justify the taxonomic segregation of these races as either distinct species or subspecies. (Discussion copyrighted by Flora of North America; reprinted with permission.)
Source	FNA vol. 12, p. 291.	FNA vol. 12, p. 286.
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. 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. 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. 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. 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 thymifolia	Chamaesyce revoluta
Name authority	Linnaeus: Sp. Pl. 1: 454. (1753)	Engelmann: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 186. (1859)
Web links	Local Web sites: LA Plants WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: CA Local Web sites: CalFlora, CalPhotos WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Euphorbia revoluta

gulf sandmat

revolute spurge, threadstem sandmat, threadstem spurge

Habit

Herbs, annual or perennial, with taproot.

Herbs, annual, with slender taproot.

Stems

prostrate, mat-forming, 15–30 cm, strigose to strigose-tomentulose.

erect, 5–25 cm, glabrous.

Leaves

opposite;

stipules distinct or slightly connate at base, linear-subulate, entire or slightly parted, 0.9–1.2 mm, strigose-tomentulose;

petiole 0.5–1 mm, sparsely strigose-tomentulose;

blade broadly elliptic to narrowly oblong or ovate-lanceolate, 3–10 × 1.8–5 mm, base asymmetric, one side usually angled or rounded and the other truncate and expanded into small, rounded auricle, margins serrate (larger leaves) to serrulate (smaller leaves), apex blunt to acute, abaxial surface sparsely tomentulose to glabrate, adaxial surface glabrate; palmately veined at base, pinnate distally.

opposite;

stipules distinct, subulate-filiform, entire, 0.5–0.9 mm, glabrous;

petiole 0.6–1.1 mm, glabrous;

blade linear, 6–27 × 0.6–1.2 mm, base symmetric, attenuate, margins entire, revolute, apex acute, sometimes mucronate, surfaces glabrous;

only midvein conspicuous.

Involucre

broadly obconic, becoming distended and distorted by base of partially included capsule, 0.4–0.8 × 0.3–0.5 mm, strigose;

glands 4, red, slightly concave, ± unequal, subcircular to broadly oval, 0.1–0.2 × 0.2–0.3 mm;

appendages white to pink, usually unequal, occasionally ± equal at distal nodes, elongated toward sinus, sometimes rudimentary, 0.1–0.4 × 0.1–0.3 mm, distal margin entire or crenulate.

obconic to campanulate, 0.7–0.9 × 0.5–0.7 mm, glabrous;

glands 4, pink to dark purple, nearly circular to oblong or reniform, 0.1 × 0.1–0.2 mm;

appendages white, oblong, nearly circular, ovate, deltate, or forming thin margin around gland, rarely absent, (0–)0.1–0.2 × (0–)0.1–0.3 mm, distal margin entire.

Staminate flowers

3–5.

5–10.

Pistillate flowers

ovary densely strigose;

styles 0.4–0.5 mm, 2-fid 1/2 length.

ovary glabrous;

styles 0.2–0.3 mm, unbranched.

Capsules

conic to truncate-ovoid, scarcely exserted from involucre, base often remaining inside involucre and splitting one side of it during maturation, 0.9–1.2 × 1–1.2 mm, sparsely to moderately strigose;

columella 0.6–1 mm.

ovoid to subglobose, 1.5–1.8 × 1.6–1.8 mm, glabrous;

columella 1.1–1.5 mm.

Seeds

white, tan underneath coat, ovoid to narrowly ovoid, sharply 4-angled in cross section, 0.8–0.9 × 0.4–0.6 mm, with 4 low transverse ridges often slightly extending into angles, not sulcate.

whitish, brick red, light gray, or light brown, narrowly to broadly ovoid, 4-angled in cross section, 0.9–1.4 × 0.7–1 mm, nearly smooth, rugulose, with faint transverse ridges, or with 2–3 well-defined transverse ridges separated by shallow depressions.

Cyathia

usually in small, cymose clusters on congested, axillary branches;

peduncle (0–)0.1–0.3 mm.

solitary at distal nodes;

peduncles absent or to 1.5 mm.

Euphorbia thymifolia

Euphorbia revoluta

Phenology

Flowering and fruiting midsummer–early fall.

Flowering and fruiting summer–late fall.

Habitat

Disturbed areas, often near salt water.

Desert scrub, sagebrush scrub, juniper woodlands, Joshua tree-pinyon pine woodlands, oak woodlands, grasslands, chaparral, pine-oak forests.

Elevation

0–20 m. (0–100 ft.)

600–2500 m. (2000–8200 ft.)

Distribution

FL; LA; Mexico; South America; West Indies [Introduced in Asia, tropical Africa, Australia]

[BONAP county map]

AZ; CA; CO; NM; NV; TX; UT; Mexico (Baja California, Chihuahua, Coahuila, Sonora, Zacatecas)

[WildflowerSearch map]

[BONAP county map]

Discussion

Euphorbia thymifolia is a widespread tropical and subtropical weed. It is not certain where the species is native, but most likely it originated in the New World and then became widespread in the rest of the tropics. Euphorbia thymifolia is present in the flora area in southern Florida and coastal Louisiana, where it is likely adventive. Euphorbia thymifolia is generally similar to E. maculata but is characterized by its short pistillate pedicels and non-exserted capsules that remain largely enclosed by the involucre and by its unequal involucral gland appendages.

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

Euphorbia revoluta is a distinctive, easily recognizable species by virtue of the combination of unbranched styles and linear leaves with symmetric bases. The species ranges through northern Mexico into the southwestern United States and is composed of three well-marked, geographically distinct races that can be distinguished by their seeds. The first of these races occurs primarily in pine-oak forest of the Sierra Madre Occidental of Mexico (Chihuahua and Sonora) and barely enters the flora area in the Huachuca Mountains of southeastern Arizona; the seeds are brick red and nearly smooth. The second race is widespread in the Chihuahuan Desert from northern Mexico to southeastern New Mexico and southwestern Texas; its seeds are whitish to light gray and possess two or three well-defined transverse ridges separated by shallow depressions. The third race corresponds to the type collection and is characterized by grayish white to light brown seeds that are rugulose or with faint transverse ridges; it occurs in northwestern Mexico (Baja California and Sonora) and throughout the arid southwestern United States. It is probable that further study will justify the taxonomic segregation of these races as either distinct species or subspecies.

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

Source

FNA vol. 12, p. 291.

FNA vol. 12, p. 286.

Parent taxa

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. 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. 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. 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. 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 thymifolia

Chamaesyce revoluta

Name authority

Linnaeus: Sp. Pl. 1: 454. (1753)

Engelmann: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 186. (1859)

Web links

Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).

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Euphorbia thymifolia

Euphorbia revoluta

Euphorbia thymifolia

Euphorbia revoluta