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beetle spurge

giant spurge, roughpod spurge, tall spurge, warty spurge

Habit Herbs, annual or perennial, with slender to thick, woody taproot. Herbs, annual or biennial, with taproot.
Stems

erect to ascending, 10–75 cm, glabrous or with scattered appressed hairs (especially near nodes);

branches arcuate.

erect, branched, 20–60 cm, glabrous.

Leaves

alternate;

petiole 0.1–0.4 mm, often indistinct, glabrous or sparsely pilose to shortly sericeous;

blade linear to linear-elliptic, 20–55 × 1–3 mm, base attenuate, margins entire or with 2–4 inconspicuous teeth near apex, apex acute, abaxial surface pilose to shortly sericeous, adaxial surface usually glabrous, rarely pilose to shortly sericeous;

only midvein conspicuous.

petiole 0–1 mm;

blade oblong-spatulate, 20–50 × 7–18 mm, base broadly attenuate, margins serrulate, apex rounded to obtuse, surfaces glabrous, ± glaucous;

venation pinnate, midvein prominent.

Involucre

obconic, 2.1–2.6 × 1.3–2 mm, canescent;

involucral lobes triangular, obscured by hairs;

glands (2–)4–5, green to maroon, color often obscured by hairs, sessile and broadly attached, 0.5–0.6 × 0.5–0.6 mm, opening oblong to nearly circular, densely canescent;

appendages petaloid, whitish, hoodlike, incurved and covering glands, 0.5–1 × 0.5–0.8 mm, divided into 5–12 fringed, subulate segments, densely canescent.

narrowly campanulate, 0.8–1.1 × 1.1–1.3 mm, glabrous;

glands 4, elliptic, 0.3–0.5 × 0.5–0.7 mm;

horns absent.

Staminate flowers

20–25.

5–10.

Pistillate flowers

ovary canescent;

styles 0.9–1.5 mm, unbranched.

ovary glabrous;

styles 0.5–0.9 mm, 2-fid.

Capsules

oblong to ovoid, 4.4–4.9 × 3.5–4.1 mm, canescent (often with interspersed glabrescent patches);

columella 3.5–3.9 mm.

depressed-globose, 2–3 × 2.5–3.5 mm, 3-lobed;

cocci rounded, papillate, papillae 0.2–0.5 mm, glabrous;

columella 1.5–1.9 mm.

Seeds

mottled black and gray or light brown, oblong or slightly ovoid, dorsiventrally compressed in cross section, 2.8–4.1 × 2–2.4 mm, irregularly pitted and tuberculate;

caruncle 0.4–0.8 × 0.6–1.1 mm.

purple-black, ovoid, 1.6–2 × 1.3–1.7 mm, reticulate and areolate;

caruncle reniform, flat, 0.5 × 0.7 mm.

Cyathial

arrangement: terminal cymose branches 1, 1–2-branched;

pleiochasial bracts 2–3, opposite or whorled, wholly green, similar in shape and size to distal leaves;

dichasial bracts similar in shape to distal leaves or often highly reduced.

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

pleiochasial bracts elliptic-oblanceolate to oblong, similar in size to distal leaves;

dichasial bracts distinct, broadly ovate to orbiculate/reniform, base obtuse, margins serrulate, apex obtuse to rounded and often mucronulate;

axillary cymose branches 6–20(–25).

Cyathia

peduncle 1–1.9 mm.

peduncle 0.5–1 mm.

Euphorbia eriantha

Euphorbia alta

Phenology Flowering and fruiting year-round in response to sufficient rainfall. Flowering and fruiting summer.
Habitat Desert scrub on rocky slopes and along washes. Montane pine-oak and mixed conifer forests, disturbed roadsides, logged areas.
Elevation 60–800 m. (200–2600 ft.) 1500–3000 m. (4900–9800 ft.)
Distribution
from FNA
AZ; CA; NM; TX; Mexico (Baja California, Baja California Sur, Chihuahua, Coahuila, Durango, San Luis Potosí, Sonora)
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; NM; Mexico
[WildflowerSearch map]
[BONAP county map]
Discussion

Euphorbia alta is a montane species from southern Arizona, New Mexico, and northern and central Mexico that is very similar to and sometimes difficult to distinguish from E. spathulata. Euphorbia alta tends to be a robust biennial, whereas E. spathulata is strictly annual. The most consistent characteristic to separate these two species is that the ovaries and capsules of E. alta are distinctly papillate, with the papillae rising sharply above the surface, whereas the ovaries and capsules of E. spathulata are merely verrucose, with the protuberances lower and rounded.

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

Source FNA vol. 12, p. 321. FNA vol. 12, p. 298.
Parent taxa Euphorbiaceae > Euphorbia > sect. Poinsettia 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. 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. 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 altus
Name authority Bentham: Bot. Voy. Sulphur, 51. (1844) Norton: N. Amer. Euphorbia, 24, plate 24. (1899)
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