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summer spurge

grassleaf spurge

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

erect or ascending, unbranched, solitary or few, previous year's dead stems not persistent, 45–70 cm, usually densely puberulent to sericeous, rarely glabrous.

erect or ascending, branched, 30–80(–110) cm, strigillose or glabrescent, sharply angled.

Leaves

alternate;

stipules to 0.1 mm;

petiole (0–)1–2 mm (or absent), densely puberulent;

blade usually linear, rarely ovate, 25–55 × 1.5–4 mm, base cuneate, margins entire, revolute, apex rounded, abaxial surface glabrous or puberulent to sericeous, adaxial surface glabrous;

venation often obscure on smaller leaves, midvein conspicuous.

usually alternate, sometimes some opposite;

stipules usually 0.2–0.5 mm, rarely rudimentary;

petiole 0.4–5.9 mm, strigillose;

blade ovate, elliptic, linear-elliptic, or oblong, 10–83 × 3–39 mm, base attenuate, rounded, or cuneate, margins entire, apex acute or obtuse, surfaces strigillose;

venation occasionally obscure on narrow leaves, midvein conspicuous.

Involucre

campanulate, 1.2–1.4 × 1.2–2 mm, sparsely to densely puberulent;

glands 5, green, reniform, 0.2–0.3 × 0.5–0.6 mm;

appendages white, orbiculate to oblong, (0.5–)1–1.7 × 1–1.5 mm, entire.

campanulate or obconic, 1–1.8 × 0.8–1.7 mm, glabrous or strigillose toward rim;

glands (1–)2–4, yellow to greenish, elliptic or oblong, 0.1–0.3 × 0.2–0.4 mm;

appendages white to tinged purple, ovate and often hoodlike or forming narrow rim around distal margin of gland, 0.3–1.6 × 0.4–0.9 mm, entire.

Staminate flowers

20–25.

30–40.

Pistillate flowers

ovary glabrous or sparsely strigose;

styles 0.5–1.1 mm, 2-fid at apex to 1/2 length.

ovary glabrous;

styles 0.7–1 mm, 2-fid from 1/2 to nearly entire length.

Capsules

globose, 1.8–3 × 2.5–4.8 mm, glabrous or sparsely strigose;

columella 2.3–2.5 mm.

ovoid-oblate, 2.5–3 × 3–3.5 mm, glabrous;

columella 1.6–1.9 mm.

Seeds

light gray, ovoid, 2 × 1.2–1.3 mm, smooth or with few, very shallow depressions;

caruncle absent.

gray, brown, or nearly black, ovoid, circular or weakly angled in cross section, 1.5–1.7 × 1.3–1.5 mm, coarsely tuberculate with longitudinal rows of shallow pits;

caruncle absent or punctiform, 0.1–0.2 mm.

Cyathia

in terminal pleiochasia;

peduncle 5–15 mm, filiform, glabrous or very sparsely puberulent to sericeous.

in usually terminal, rarely axillary, dichasia, distal dichasial bracts often white;

peduncle 0.4–4.5 mm (to 15 mm at first node of inflorescence), glabrous.

Euphorbia discoidalis

Euphorbia graminea

Phenology Flowering and fruiting late spring–fall. Flowering and fruiting year-round.
Habitat Sand hills, pine savannas, woodland borders, open fields with sandy soils. Disturbed, weedy, or urban areas.
Elevation 0–150 m. (0–500 ft.) 0–500 m. (0–1600 ft.)
Distribution
from FNA
AL; FL; GA; LA; MS; TX
[WildflowerSearch map]
[BONAP county map]
from FNA
AR; CA; FL; LA; TX; Mexico; Central America; South America [Introduced in North America; introduced also in West Indies, Asia, Pacific Islands]
[WildflowerSearch map]
[BONAP county map]
Discussion

M. J. Huft (1979) remarked that Euphorbia discoidalis is uncommon west of Alabama and referred many narrow-leaved specimens from Louisiana and Texas to E. corollata. K. R. Park (1998) included them in an expanded E. discoidalis, and that is followed here. The western populations can be distinguished from E. corollata by their shorter involucral gland appendages and revolute leaf margins. Further study of these western populations is warranted.

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

Euphorbia graminea occurs natively from northern South America to northern Mexico. The species is a variable and taxonomically complex entity whose boundaries are not well defined and are in need of further study. Euphorbia graminea is often weedy and has recently become established in warmer areas of the southern United States, where it will likely become more common in the future. In recent years, a cultivar of E. graminea has found considerable horticultural success and is marketed under the trade name "Diamond Frost."

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

Source FNA vol. 12, p. 245. FNA vol. 12, p. 246.
Parent taxa Euphorbiaceae > Euphorbia > sect. Alectoroctonum Euphorbiaceae > Euphorbia > sect. Alectoroctonum
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. 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. 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. 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 Tithymalopsis discoidalis
Name authority Chapman: Fl. South. U.S., 401. (1860) Jacquin: Select. Stirp. Amer. Hist., 151. (1763)
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