Flora of North America species comparison

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Euphorbia helioscopia

Euphorbia crenulata

euphorbe réveille-matin, mad woman's milk, summer spurge, sun spurge, wart spurge, wartweed

Chinese caps, western wood spurge
Habit Herbs, annual, with taproot. Herbs, usually biennial, occasionally annual, with taproot.
Stems

erect, unbranched or branched, 5–45 cm, usually glabrous or sparsely pilose.

erect, sometimes decumbent at base, unbranched or branched, 12–40 cm, glabrous.
Leaves

petiole absent or to 0.5 mm;

blade obovate-spatulate, 4–40 × 2–25 mm, base cuneate, attenuate, or auriculate, margins serrulate, apex rounded, surfaces glabrous;

venation pinnate, midvein prominent.

petiole 0–2 mm;

blade obovate-spatulate to oblanceolate, 8–22 × 3–10 mm, base broadly attenuate, margins entire or slightly crisped, apex obtuse to ± rounded, minutely apiculate, surfaces glabrous;

venation pinnate, midvein prominent.
Involucre

cupulate, 1.5–2 × 0.7–1.1 mm, glabrous;

glands 4, elliptic, 0.2–0.5 × 0.5–1 mm;

horns absent.

campanulate, 1.8–2.1 × 1.6–1.8 mm, glabrous;

glands 4, crescent-shaped, 0.6–1.2 × 1.5–2.3 mm;

horns slightly divergent to slightly convergent, 0.4–0.6 mm.
Staminate flowers

10–15.

11–18.
Pistillate flowers

ovary glabrous;

styles 0.7–1 mm, 2-fid.

ovary glabrous;

styles 0.9–1.4 mm, 2-fid.
Capsules

depressed-globose, 2.5–4 × 3.2–4.2 mm, clearly 3-lobed;

cocci rounded, smooth, glabrous;

columella 0.9–1.1 mm.

subovoid, 2.5–3 × 3.5–4 mm, 3-lobed;

cocci rounded, smooth or puncticulate, glabrous;

columella 1.9–2.3 mm.
Seeds

dark brown to blackish, subovoid, 1.6–2.2 × 1.5–1.9 mm, reticulate;

caruncle elliptic, 0.9–1.1 × 0.4–0.5 mm.

cream and brown mottled, oblong-ovoid to nearly globose, 2–2.5 × 1.4–1.7 mm, usually irregularly vermiculate-ridged and large-pitted, occasionally tuberculate or nearly smooth;

caruncle reniform, conic, 0.5–0.6 × 0.5–0.7 mm.
Cyathial

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

pleiochasial bracts obovate, wider than distal leaves;

dichasial bracts distinct, obovate or rhombic, ± oblique, base rounded, truncate, or attenuate, margins serrulate, apex rounded;

axillary cymose branches 0.

arrangement: terminal pleiochasial branches 3, each 2-branched;

pleiochasial bracts obovate to orbiculate-reniform, wider than distal leaves;

dichasial bracts usually connate 1/3–1/2 length (often only on one side), rarely only connate basally, triangular ovate to reniform, base truncate to perfoliate, margins erose-denticulate to subentire, apex rounded to obtuse, rarely apiculate;

axillary cymose branches 0–5.
Cyathia

peduncle 0.2–1 mm.

peduncle 0–0.5 mm.

Euphorbia helioscopia

Euphorbia crenulata
Phenology Flowering and fruiting spring–fall. Flowering and fruiting spring–summer.
Habitat Roadsides, waste places. Conifer, oak, and mixed forests, coastal scrub, grasslands, barrens and outcrops, roadsides.
Elevation 0–1400 m. (0–4600 ft.) 30–1800 m. (100–5900 ft.)
Distribution
from FNA
CA; CT; DC; DE; GA; ID; IL; LA; MA; MD; ME; MI; MT; NC; NH; NJ; NY; OH; OR; PA; SC; TN; TX; VA; VT; WA; WI; WY; AB; BC; NB; NF; NS; ON; PE; QC; SK; Europe; Asia; n Africa [Introduced in North America; introduced also in South America (Argentina, Chile)]
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; CO; NM; OR
[WildflowerSearch map]
[BONAP county map]
Discussion

Euphorbia helioscopia was collected once in Minnesota in the late 1800s but apparently did not become established there.

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

Euphorbia crenulata is most common in the central valleys of California and southern Oregon; it occurs disjunctly in southwestern Colorado and northwestern New Mexico. Previous reports from Arizona are based on misidentified specimens. Euphorbia crenulata is closely related to E. commutata.

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Source FNA vol. 12, p. 303. FNA vol. 12, p. 301.
Parent taxa Euphorbiaceae > Euphorbia > subg. Esula Euphorbiaceae > Euphorbia > subg. Esula
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. 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. 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. 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 Galarhoeus helioscopius, Tithymalus helioscopius Tithymalus crenulatus
Name authority Linnaeus: Sp. Pl. 1: 459. (1753) Engelmann: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 192. (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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