FNA: Euphorbia lurida vs. Euphorbia acuta

	Euphorbia lurida	Euphorbia acuta
	woodland spurge	point sandmat
Habit	Herbs, perennial, with thick rootstock.	Herbs, perennial, with strongly thickened rootstock.
Stems	erect or ascending, unbranched, sometimes sinuous, 5–30 cm, glabrous or sparsely to densely puberulent.	ascending to erect, 5–30 cm, uniformly and densely canescent or sericeous.
Leaves	petiole 0–1 mm; blade oblanceolate to obovate, 8–20 mm × 3–7 mm, base truncate or cuneate, margins entire, apex obtuse to rounded, minutely mucronate, surfaces puberulent or glabrous; venation inconspicuous, only midvein prominent.	opposite; stipules deciduous, sometimes appearing absent, distinct, brown, linear-subulate, thin, 0.3–0.8 mm, canescent; petiole 0.4–1.2 mm, moderately to densely canescent; blade ovate to lanceolate, 6–20 × 3–8 mm, base subsymmetric, rounded to cuneate, margins entire, strongly involute, apex long-acuminate, spinulose, abaxial surface canescent to densely sericeous, adaxial surface glabrous or sparsely canescent; 3-veined from base but only midvein conspicuous.
Involucre	cupulate, 2–2.2 × 1.3–1.8 mm, glabrous; glands 4, oblong to broadly ovate, usually truncate, 0.5–0.8 × 1–1.6 mm, margins irregularly crenate to strongly dentate; horns absent or usually divergent or straight, 0.1–0.3 mm, usually slightly longer than, occasionally equaling, teeth on gland margin.	turbinate to urceolate, 2–2.6 × 1.7–2.5 mm, villous to lanate; glands 4, yellow-green to orange or red, slightly concave, oblong-elliptic, 0.2–0.4 × 0.6–1.5 mm; appendages white, flabellate, 1.1–2.1 × 0.2–0.6 mm, distal margin shallowly and irregularly toothed.
Staminate flowers	10–20.	20–25.
Pistillate flowers	ovary glabrous or puberulent; styles 0.7–1 mm, 2-fid.	ovary strigose, pubescent to villous; styles 0.6–0.9 mm, 2-fid 1/2 length.
Capsules	ovoid, 3.5–4 × 4–4.5 mm, 3-lobed; cocci rounded, smooth to slightly rugose, glabrous; columella 3.2–3.5 mm.	subglobose to broadly ovoid, 2.8–3.7 mm diam., strigose, pubescent to villous; columella 2.3–3 mm.
Seeds	gray to dark gray, truncate-oblong to truncate-ovoid, 2.8–3 × 1.7–2 mm, irregularly pitted; caruncle conic, 0.6 × 0.7 mm.	white, ovoid, 4-angled in cross section, 2.2–2.6 × 1.1–1.4 mm, smooth to finely reticulate.
Cyathial	arrangement: terminal pleiochasial branches 3–5, each 1–4 times 2-branched; pleiochasial bracts ovate to broadly ovate or oblanceolate, wider than distal leaves; dichasial bracts distinct, rounded, oblanceolate, or subreniform, base cuneate or obtuse, margins entire, apex obtuse, slightly mucronate; axillary cymose branches 0–4.
Cyathia	peduncle 0.3–0.9 mm.	solitary at distal nodes; peduncle 1.3–3.2 mm.
2n		= 28, 48, 56.

	Euphorbia lurida	Euphorbia acuta
Phenology	Flowering and fruiting spring–summer.	Flowering and fruiting spring–fall.
Habitat	Open pine-oak forests, dry slopes and canyons.	Desert scrub, grasslands, oak-juniper savannas, limestone, rocky, sandy, or clay soils.
Elevation	1300–2800 m. (4300–9200 ft.)	400–1900 m. (1300–6200 ft.)
Distribution	AZ; CA; NM; NV; UT; Mexico (Baja California) [WildflowerSearch map] [BONAP county map]	NM; TX; Mexico (Chihuahua, Coahuila)
Discussion	Euphorbia lurida has been treated as a complex of several taxa in the past, but only a single, broadly-defined species is recognized here. This species is variable in both the pubescence and shape of the bracts subtending the cyathia and also in the degree of crenation of the gland margin. In the northern part of its range, E. lurida appears to intergrade with E. brachycera, and it can be difficult to distinguish these two species in northern Arizona and New Mexico. A report of the species from Sonora, Mexico, based on a single immature collection (V. W. Steinmann and R. S. Felger 1997) has not been verified. (Discussion copyrighted by Flora of North America; reprinted with permission.)	Euphorbia acuta is easily distinguished in the field by its relatively large, strongly involute, hairy, and acutely pointed leaves. The name Euphorbia acuta Engelmann has been proposed for conservation against the earlier name E. acuta Bellardi ex Colla (P. E. Berry et al. 2011). (Discussion copyrighted by Flora of North America; reprinted with permission.)
Source	FNA vol. 12, p. 305.	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. 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. 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. 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. thymifolia, E. tithymaloides, E. trachysperma, E. trichotoma, E. vallis-mortae, E. velleriflora, E. vermiculata, E. villifera, E. virgata, E. wrightii, E. yaquiana
Synonyms	E. palmeri, E. palmeri var. subpubens, E. subpubens, Tithymalus luridus, T. palmeri, T. subpubens	Chamaesyce acuta, E. acuta var. stenophylla, E. georgei
Name authority	Engelmann: in J. C. Ives, Rep. Colorado R. 4: 26. (1861)	Engelmann: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 189. (1859) — name proposed for conservation
Web links	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	WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Euphorbia acuta

woodland spurge

point sandmat

Habit

Herbs, perennial, with thick rootstock.

Herbs, perennial, with strongly thickened rootstock.

Stems

erect or ascending, unbranched, sometimes sinuous, 5–30 cm, glabrous or sparsely to densely puberulent.

ascending to erect, 5–30 cm, uniformly and densely canescent or sericeous.

Leaves

petiole 0–1 mm;

blade oblanceolate to obovate, 8–20 mm × 3–7 mm, base truncate or cuneate, margins entire, apex obtuse to rounded, minutely mucronate, surfaces puberulent or glabrous;

venation inconspicuous, only midvein prominent.

opposite;

stipules deciduous, sometimes appearing absent, distinct, brown, linear-subulate, thin, 0.3–0.8 mm, canescent;

petiole 0.4–1.2 mm, moderately to densely canescent;

blade ovate to lanceolate, 6–20 × 3–8 mm, base subsymmetric, rounded to cuneate, margins entire, strongly involute, apex long-acuminate, spinulose, abaxial surface canescent to densely sericeous, adaxial surface glabrous or sparsely canescent; 3-veined from base but only midvein conspicuous.

Involucre

cupulate, 2–2.2 × 1.3–1.8 mm, glabrous;

glands 4, oblong to broadly ovate, usually truncate, 0.5–0.8 × 1–1.6 mm, margins irregularly crenate to strongly dentate;

horns absent or usually divergent or straight, 0.1–0.3 mm, usually slightly longer than, occasionally equaling, teeth on gland margin.

turbinate to urceolate, 2–2.6 × 1.7–2.5 mm, villous to lanate;

glands 4, yellow-green to orange or red, slightly concave, oblong-elliptic, 0.2–0.4 × 0.6–1.5 mm;

appendages white, flabellate, 1.1–2.1 × 0.2–0.6 mm, distal margin shallowly and irregularly toothed.

Staminate flowers

10–20.

20–25.

Pistillate flowers

ovary glabrous or puberulent;

styles 0.7–1 mm, 2-fid.

ovary strigose, pubescent to villous;

styles 0.6–0.9 mm, 2-fid 1/2 length.

Capsules

ovoid, 3.5–4 × 4–4.5 mm, 3-lobed;

cocci rounded, smooth to slightly rugose, glabrous;

columella 3.2–3.5 mm.

subglobose to broadly ovoid, 2.8–3.7 mm diam., strigose, pubescent to villous;

columella 2.3–3 mm.

Seeds

gray to dark gray, truncate-oblong to truncate-ovoid, 2.8–3 × 1.7–2 mm, irregularly pitted;

caruncle conic, 0.6 × 0.7 mm.

white, ovoid, 4-angled in cross section, 2.2–2.6 × 1.1–1.4 mm, smooth to finely reticulate.

Cyathial

arrangement: terminal pleiochasial branches 3–5, each 1–4 times 2-branched;

pleiochasial bracts ovate to broadly ovate or oblanceolate, wider than distal leaves;

dichasial bracts distinct, rounded, oblanceolate, or subreniform, base cuneate or obtuse, margins entire, apex obtuse, slightly mucronate;

axillary cymose branches 0–4.

Cyathia

peduncle 0.3–0.9 mm.

solitary at distal nodes;

peduncle 1.3–3.2 mm.

= 28, 48, 56.

Euphorbia lurida

Euphorbia acuta

Phenology

Flowering and fruiting spring–summer.

Flowering and fruiting spring–fall.

Habitat

Open pine-oak forests, dry slopes and canyons.

Desert scrub, grasslands, oak-juniper savannas, limestone, rocky, sandy, or clay soils.

Elevation

1300–2800 m. (4300–9200 ft.)

400–1900 m. (1300–6200 ft.)

Distribution

AZ; CA; NM; NV; UT; Mexico (Baja California)

[WildflowerSearch map]

[BONAP county map]

NM; TX; Mexico (Chihuahua, Coahuila)

Discussion

Euphorbia lurida has been treated as a complex of several taxa in the past, but only a single, broadly-defined species is recognized here. This species is variable in both the pubescence and shape of the bracts subtending the cyathia and also in the degree of crenation of the gland margin. In the northern part of its range, E. lurida appears to intergrade with E. brachycera, and it can be difficult to distinguish these two species in northern Arizona and New Mexico. A report of the species from Sonora, Mexico, based on a single immature collection (V. W. Steinmann and R. S. Felger 1997) has not been verified.

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

Euphorbia acuta is easily distinguished in the field by its relatively large, strongly involute, hairy, and acutely pointed leaves. The name Euphorbia acuta Engelmann has been proposed for conservation against the earlier name E. acuta Bellardi ex Colla (P. E. Berry et al. 2011).

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

Source

FNA vol. 12, p. 305.

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. 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. 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. 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. thymifolia, E. tithymaloides, E. trachysperma, E. trichotoma, E. vallis-mortae, E. velleriflora, E. vermiculata, E. villifera, E. virgata, E. wrightii, E. yaquiana

Synonyms

E. palmeri, E. palmeri var. subpubens, E. subpubens, Tithymalus luridus, T. palmeri, T. subpubens

Chamaesyce acuta, E. acuta var. stenophylla, E. georgei

Name authority

Engelmann: in J. C. Ives, Rep. Colorado R. 4: 26. (1861)

Engelmann: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 189. (1859) — name proposed for conservation

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).

Choose a data source: Flora of North America

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Euphorbia lurida

Euphorbia acuta

Euphorbia lurida

Euphorbia acuta