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Balkan spurge, egg-leaf spurge, oblong spurge

Marble Canyon spurge, Ross' or Marble Canyon spurge

Habit Herbs, perennial, with woody taproot. Herbs, perennial, with deep stout rootstock.
Stems

erect, unbranched or densely branching, 80 cm, often densely villous (especially young stems and pleiochasial branches).

erect, branched, densely clumped, previous year’s dead stems persistent, 25–45(–60) cm, glabrous, striate.

Leaves

petiole absent;

blade oblong to narrowly obovate or lanceolate, 15–70 × 6–25 mm, base rounded or truncate, margins finely serrulate, apex obtuse, mucronulate, surfaces glabrous;

venation inconspicuously pinnate, midvein prominent.

alternate, persisting, usually reflexed, occasionally spreading;

stipules 0.1–0.3 mm;

petiole 0.2–2.2 mm, glabrous;

blade narrowly ovate to lanceolate proximally, narrowly lanceolate, linear, or filiform distally, 10–32 × 0.5–6.5 mm, base cuneate, margins entire, apex acute, surfaces pilose when young, sparsely strigose or glabrous with age;

venation obscure, only midvein conspicuous.

Involucre

cupulate to slightly turbinate, 1.5–2.5 × 1.3–1.5 mm, glabrous;

glands 2–3, elliptic, 0.6–0.8 × 0.8–1.2 mm;

horns absent.

turbinate to campanulate, 2.2–3.7 × 1.5–2.5 mm, moderately strigose;

glands 5, dark green, reniform, 0.7–1.1 × 1–1.6 mm;

appendages white to pink, flabellate, 0.5–1.5 × 0.8–2.2 mm, dentate or erose.

Staminate flowers

15–40.

20–25.

Pistillate flowers

ovary glabrous;

styles 1.5–2 mm, 2-fid.

ovary strigose;

styles 1–1.3 mm, 2-fid at apex.

Capsules

globose, 3–4.5 × 3–4.5 mm, slightly 3-lobed;

cocci rounded, verrucose-tuberculate, glabrous;

columella 2.5–3.3 mm.

subglobose, 2–3 × 4 mm, sparsely strigose;

columella 2–3 mm.

Seeds

brown, ovoid, 2.4–2.6 × 1.3–2 mm, smooth, caruncle reniform, 0.2–0.3 × 0.8–0.9 mm.

gray-green to gray-brown, globose-ovoid, 1.8–2.2 × 1.2–1.6 mm, longitudinally pitted;

caruncle absent.

Cyathial

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

pleiochasial bracts ovate, similar in size to distal leaves;

dichasial bracts distinct, ovate to suborbiculate, base truncate or rounded, margins entire or finely denticulate, apex obtuse, sometimes mucronulate;

axillary cymose branches 0–4.

Cyathia

peduncle 1–5 mm.

in terminal monochasia (thus appearing solitary at alternate nodes);

peduncle 0.5–2.5 (or 10–25) mm, glabrous or sparsely strigose.

Euphorbia oblongata

Euphorbia aaron-rossii

Phenology Flowering and fruiting spring–fall. Flowering and fruiting spring–fall.
Habitat Waste areas, disturbed sites, roadsides, fields, pastures. Sandy soils and dunes, occasionally rocky slopes, riparian areas.
Elevation 30–900 m. (100–3000 ft.) 600–1300 m. (2000–4300 ft.)
Distribution
from FNA
CA; OR; WA; s Europe [Introduced in North America]
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ
[BONAP county map]
Discussion

Euphorbia oblongata is listed as a noxious weed by the states of California, Oregon, and Washington.

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

Euphorbia aaron-rossii is restricted to the banks of the Colorado River in several small areas of the Grand and Marble canyons. The species is most closely related to E. strictior and E. wrightii, but due to its rarity, it has not been extensively studied.

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

Source FNA vol. 12, p. 305. FNA vol. 12, p. 242.
Parent taxa Euphorbiaceae > Euphorbia > subg. Esula 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. 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. 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. 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. 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 Tithymalus oblongatus
Name authority Grisebach: Spic. Fl. Rumel. 1: 136. (1843) A. H. Holmgren & N. H. Holmgren: Brittonia 40: 357, figs. 1, 2. (1988)
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