The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

snow-on-the-prairie

cypress spurge, euphorbe cypress, graveyard spurge

Habit Herbs, annual, with taproot. Herbs, perennial, with slender, spreading rootstock.
Stems

erect, unbranched or branched, 40–100 cm, pilose.

erect or ascending, unbranched or branched, often with short axillary vegetative shoots with very narrow leaves, 10–50 cm, glabrous.

Leaves

alternate;

stipules 0.3–0.4 mm;

petiole 0.3–1 mm, pilose;

blade narrowly elliptic to lanceolate, 37–54 × 7–17 mm, base cuneate to slightly rounded, margins entire, apex aristate or acute, surfaces pilose;

venation obscure, only midvein conspicuous.

petiole absent;

blade linear to linear-ovate or linear-oblanceolate, 5–30 × 0.5–3 mm, base rounded to cuneate, margins entire, apex rounded to acute, surfaces glabrous;

venation inconspicuous, only midvein prominent.

Involucre

campanulate, 2.7–3.5 × 2.2–3 mm, densely pilose;

glands 4–5, green to pale greenish yellow, reniform, 0.6–0.7 × 1.4–1.6 mm;

appendages white, obdeltate to orbiculate, 1.4–2.5 × 1.7–3 mm, dentate to erose.

campanulate to slightly urceolate, 1.5–2 × 0.9–1.1 mm, glabrous;

glands 4, crescent-shaped; 0.4–0.6 × 0.7–1.3 mm;

horns convergent, 0.1–0.5 mm.

Staminate flowers

30–70.

15–25.

Pistillate flowers

ovary pilose;

styles 0.7–1.2 mm, 2-fid 1/2 length.

ovary glabrous;

styles 1–1.2 mm, 2-fid.

Capsules

depressed-ovoid, 3.5–7.5 × 6–8.7 mm, densely pilose;

columella 4.5–5.5 mm.

subglobose, 2.5–3 × 3–4 mm, slightly lobed;

cocci rounded, granulate, glabrous;

columella 1.9–2.1 mm.

Seeds

tan to brown, ovoid, 4.3–4.5 × 3.7–3.9 mm, alveolate;

caruncle absent.

blackish, ovoid-oblong, 1.8–2.5 × 1.4–1.7 mm, smooth;

caruncle nipple-shaped or subreniform, 0.2–0.4 × 0.7–1.1 mm.

Cyathia

in terminal pleiochasia dichasial and pleiochasial bracts linear to narrowly oblanceolate, with conspicuous white margins;

peduncle 1.2–3 mm, densely pilose.

peduncle 0–0.5 mm.

Cyathial

arrangement: terminal pleiochasial branches 6–25, each 1–2-times 2-branched;

pleiochasial bracts similar in shape to distal leaves except shorter and wider;

dichasial bracts distinct, widely ovate, rhombic or reniform, base obtuse to truncate, margins entire, apex acute or obtuse, sometimes mucronulate;

axillary cymose branches 0–15.

Euphorbia bicolor

Euphorbia cyparissias

Phenology Flowering and fruiting summer–fall. Flowering and fruiting spring–fall.
Habitat Prairies, blackland (calcareous) prairies, pastures and clearings in former blackland prairie areas, roadside clearings. Fields, roadsides, waste places.
Elevation 100–200 m. (300–700 ft.) 0–1500 m. (0–4900 ft.)
Distribution
from FNA
AR; LA; OK; TX
[WildflowerSearch map]
[BONAP county map]
from FNA
AR; CA; CO; CT; DC; DE; GA; IA; ID; IL; IN; KY; MA; MD; ME; MI; MN; MO; MT; NC; NE; NH; NJ; NY; OH; OR; PA; RI; SC; TN; UT; VA; VT; WA; WI; WV; WY; BC; MB; NB; NF; NS; ON; PE; QC; SK; Europe [Introduced in North America]
[WildflowerSearch map]
[BONAP county map]
Discussion

Euphorbia bicolor is similar in appearance to E. marginata but can be distinguished by its linear to narrowly oblanceolate bracts and the presence of hairs on all parts of the plant.

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

Source FNA vol. 12, p. 243. FNA vol. 12, p. 301.
Parent taxa Euphorbiaceae > Euphorbia > sect. Alectoroctonum 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. 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
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. 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 cyparissias, Tithymalus cyparissias
Name authority Engelmann & A. Gray: Boston J. Nat. Hist. 5: 233. (1845) Linnaeus: Sp. Pl. 1: 461. (1753)
Web links