FNA: Euphorbia humistrata vs. Euphorbia rayturneri

	Euphorbia humistrata	Euphorbia rayturneri
	spreading sandmat
Habit	Herbs, annual, with taproot.	Herbs, annual, with slender taproot.
Stems	prostrate to ascending, usually mat-forming and rooting at nodes, 5–45 cm, sparsely to moderately villous to pilose (densely on young growth).	prostrate, 4–8 cm, uniformly strigillose.
Leaves	opposite; stipules distinct, linear-subulate, often irregularly 2- or 3-lobed, 1–1.3 mm, sparsely villous to pilose; petiole 0.5–1.5 mm, sparsely to moderately villous to pilose; blade oblong-ovate to ovate-elliptic or oblong-elliptic, 4–18 × 2.5–8 mm, base strongly asymmetric, one side angled and other rounded to auriculate, margin on longer side serrulate, on shorter side subentire, apex rounded or broadly acute, abaxial surface pale grayish green, sparsely lanulose, adaxial surface usually with irregular reddish streak along midvein, usually glabrate, rarely sparsely lanulose; palmately veined at base, pinnate distally.	opposite; stipules distinct, filiform, 0.6–0.9 mm, pilose; petiole 0.5–0.9 mm, strigillose; blade ovate to elliptic, often slightly falcate, 5–11 × 2–5 mm, base asymmetric, one side cordate, other round to attenuate, margins sharply serrulate, apex acute, surfaces often with red spot toward middle, abaxial surface strigillose, adaxial surface glabrescent; only midvein conspicuous.
Involucre	obconic, 0.8–1 × 0.6–0.8 mm, sparsely villous to pilose; glands 4, green to yellow-green (turning pink with age), usually ± unequal, narrowly oblong, 0.1–0.2 × 0.2–0.5 mm; appendages white to reddish tinged, lunate, ± irregular and variable in shape, 0.1–0.3 × 0.2–1.5 mm, distal margin crenulate.	obconic, 0.9–1.2 × 0.8–1.2 mm, strigillose; glands 4, green, yellow, or light pink, circular to oblong, 0.2 × 0.2–0.3 mm; appendages absent or green, yellow, or light pink, forming narrow margin on distal portion of gland, 0–0.1 × 0.2–0.3 mm, distal margin entire.
Staminate flowers	2–5.	5–8.
Pistillate flowers	ovary short-sericeous; styles 0.5–0.8 mm, 2-fid 1/2 length.	ovary strigillose-canescent; styles 0.3–0.4 mm, unbranched.
Capsules	ovoid, well exserted from involucre at maturity, 1.3–1.5 × 1.2–1.6 mm, sparsely to moderately short-sericeous; columella 0.9–1.2 mm.	oblate, 1.7–2 × 2.2–2.7 mm, strigillose; columella 1.5–1.9 mm.
Seeds	white to light brown, oblong-ovoid, bluntly angular in cross section, 0.8–1.2 × 0.5–0.9 mm, smooth or papillate.	blackish brown, broadly ovoid, 3-angled in cross section, 1.2–1.4 × 1–1.1 mm, with 2 well-defined transverse ridges that do not pass through abaxial keel.
Cyathia	solitary at distal nodes; peduncle 0.1–0.6(–2) mm.	solitary at distal nodes; peduncle 0.5–1.6 mm.
2n		= 14.

	Euphorbia humistrata	Euphorbia rayturneri
Phenology	Flowering and fruiting spring–late summer.	Flowering and fruiting late summer–early fall.
Habitat	Stream and river banks, gravel bars, floodplains, pond edges, disturbed fields, railroads, roadsides.	Desert grasslands.
Elevation	0–300 m. (0–1000 ft.)	1400–1700 m. (4600–5600 ft.)
Distribution	AL; AR; FL; GA; IL; IN; KS; KY; LA; MO; MS; OH; OK; TN; TX; VA; WV [WildflowerSearch map] [BONAP county map]	NM
Discussion	Euphorbia humistrata is distributed throughout the Mississippi River valley and along other major river systems in the central and eastern United States. There are scattered reports of this species as a waif or as introduced farther north and/or east (for example, Minnesota, New York, North Carolina, Ontario, South Dakota, and Wisconsin), but the authors have not been able to verify these occurrences. Euphorbia humistrata is similar to E. maculata and is often confused with that species in herbaria. It can be distinguished from E. maculata by its tendency to root at the stem nodes, its longer styles, and its seeds that lack low transverse ridges and that are more bluntly angled. When growing side-by-side, E. humistrata has an overall less congested appearance and its cyathia are not as numerous or crowded as those of E. maculata. (Discussion copyrighted by Flora of North America; reprinted with permission.)	Euphorbia rayturneri is known from only three collections in extreme southwestern New Mexico. Given its close proximity to the Mexican border, the species may also occur in the adjacent states of Chihuahua or Sonora. (Discussion copyrighted by Flora of North America; reprinted with permission.)
Source	FNA vol. 12, p. 272.	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. 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. 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. 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 humistrata
Name authority	Engelmann: in A. Gray, Manual ed. 2, 386. (1856)	V. W. Steinmann & Jercinovic: Novon 22: 482, figs. 1, 2. (2013)
Web links	Local Web sites: IL Wildflowers, KS Wildflowers, LA Plants, MO Plants WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Euphorbia rayturneri

spreading sandmat

Habit

Herbs, annual, with taproot.

Herbs, annual, with slender taproot.

Stems

prostrate to ascending, usually mat-forming and rooting at nodes, 5–45 cm, sparsely to moderately villous to pilose (densely on young growth).

prostrate, 4–8 cm, uniformly strigillose.

Leaves

opposite;

stipules distinct, linear-subulate, often irregularly 2- or 3-lobed, 1–1.3 mm, sparsely villous to pilose;

petiole 0.5–1.5 mm, sparsely to moderately villous to pilose;

blade oblong-ovate to ovate-elliptic or oblong-elliptic, 4–18 × 2.5–8 mm, base strongly asymmetric, one side angled and other rounded to auriculate, margin on longer side serrulate, on shorter side subentire, apex rounded or broadly acute, abaxial surface pale grayish green, sparsely lanulose, adaxial surface usually with irregular reddish streak along midvein, usually glabrate, rarely sparsely lanulose; palmately veined at base, pinnate distally.

opposite;

stipules distinct, filiform, 0.6–0.9 mm, pilose;

petiole 0.5–0.9 mm, strigillose;

blade ovate to elliptic, often slightly falcate, 5–11 × 2–5 mm, base asymmetric, one side cordate, other round to attenuate, margins sharply serrulate, apex acute, surfaces often with red spot toward middle, abaxial surface strigillose, adaxial surface glabrescent;

only midvein conspicuous.

Involucre

obconic, 0.8–1 × 0.6–0.8 mm, sparsely villous to pilose;

glands 4, green to yellow-green (turning pink with age), usually ± unequal, narrowly oblong, 0.1–0.2 × 0.2–0.5 mm;

appendages white to reddish tinged, lunate, ± irregular and variable in shape, 0.1–0.3 × 0.2–1.5 mm, distal margin crenulate.

obconic, 0.9–1.2 × 0.8–1.2 mm, strigillose;

glands 4, green, yellow, or light pink, circular to oblong, 0.2 × 0.2–0.3 mm;

appendages absent or green, yellow, or light pink, forming narrow margin on distal portion of gland, 0–0.1 × 0.2–0.3 mm, distal margin entire.

Staminate flowers

2–5.

5–8.

Pistillate flowers

ovary short-sericeous;

styles 0.5–0.8 mm, 2-fid 1/2 length.

ovary strigillose-canescent;

styles 0.3–0.4 mm, unbranched.

Capsules

ovoid, well exserted from involucre at maturity, 1.3–1.5 × 1.2–1.6 mm, sparsely to moderately short-sericeous;

columella 0.9–1.2 mm.

oblate, 1.7–2 × 2.2–2.7 mm, strigillose;

columella 1.5–1.9 mm.

Seeds

white to light brown, oblong-ovoid, bluntly angular in cross section, 0.8–1.2 × 0.5–0.9 mm, smooth or papillate.

blackish brown, broadly ovoid, 3-angled in cross section, 1.2–1.4 × 1–1.1 mm, with 2 well-defined transverse ridges that do not pass through abaxial keel.

Cyathia

solitary at distal nodes;

peduncle 0.1–0.6(–2) mm.

solitary at distal nodes;

peduncle 0.5–1.6 mm.

= 14.

Euphorbia humistrata

Euphorbia rayturneri

Phenology

Flowering and fruiting spring–late summer.

Flowering and fruiting late summer–early fall.

Habitat

Stream and river banks, gravel bars, floodplains, pond edges, disturbed fields, railroads, roadsides.

Desert grasslands.

Elevation

0–300 m. (0–1000 ft.)

1400–1700 m. (4600–5600 ft.)

Distribution

AL; AR; FL; GA; IL; IN; KS; KY; LA; MO; MS; OH; OK; TN; TX; VA; WV

[WildflowerSearch map]

[BONAP county map]

Discussion

Euphorbia humistrata is distributed throughout the Mississippi River valley and along other major river systems in the central and eastern United States. There are scattered reports of this species as a waif or as introduced farther north and/or east (for example, Minnesota, New York, North Carolina, Ontario, South Dakota, and Wisconsin), but the authors have not been able to verify these occurrences. Euphorbia humistrata is similar to E. maculata and is often confused with that species in herbaria. It can be distinguished from E. maculata by its tendency to root at the stem nodes, its longer styles, and its seeds that lack low transverse ridges and that are more bluntly angled. When growing side-by-side, E. humistrata has an overall less congested appearance and its cyathia are not as numerous or crowded as those of E. maculata.

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

Euphorbia rayturneri is known from only three collections in extreme southwestern New Mexico. Given its close proximity to the Mexican border, the species may also occur in the adjacent states of Chihuahua or Sonora.

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

Source

FNA vol. 12, p. 272.

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. 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. 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. 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 humistrata

Name authority

Engelmann: in A. Gray, Manual ed. 2, 386. (1856)

V. W. Steinmann & Jercinovic: Novon 22: 482, figs. 1, 2. (2013)

Web links

Local Web sites: IL Wildflowers, KS Wildflowers, LA Plants, MO Plants
WildflowerSearch
iNaturalist (observations)
USDA Plants Database
LBJ Wildflower Center
SEINet
Plants of the World Online
Encyclopedia of Life
Wikipedia
Google Image Search

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).

Choose a data source: Flora of North America

The species comparison tool is brought to you by:

Flora of North America species comparison

Euphorbia humistrata

Euphorbia rayturneri

Euphorbia humistrata

Euphorbia rayturneri