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square-seed spurge, squareseed or Clark Mountain spurge

telephus spurge

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

erect, 5–26 cm, uniformly puberulent to hispidulous or glabrous;

branches arcuate.

erect or ascending, 20–30 cm.

Leaves

opposite;

petiole 1–3 mm, often indistinct, glabrous or puberulent;

blade linear to narrowly elliptic or ovate, 14–42 × 3–28 mm, base attenuate, margins coarsely serrate, occasionally revolute, apex acute to obtuse, abaxial surface sparsely hispidulous to strigillose, adaxial surface glabrous;

midvein conspicuous.

petiole usually absent or indistinct, occasionally to 5.5 mm, blade elliptic or obovate, 31–60 × 7–32 mm, thick and fleshy, base attenuate or cuneate, apex acute, obtuse, or mucronate;

venation pinnate with 8–13 lateral veins, these sometimes obscure and only midvein evident.

Involucre

turbinate to campanulate, 1.1–1.5 × 1–1.3 mm, glabrous, pilose or puberulent;

involucral lobes divided into several linear lobes;

glands 4(–5), yellow to pink, sessile and broadly attached, 0.2 × 0.3–0.4 mm, opening oblong to nearly circular, glabrous;

appendages usually petaloid, white to pink, ovate to trapezoidal, occasionally absent, not incurved and covering glands, 0.2–0.4 × 0.3–0.8 mm, entire, undulate, or conspicuously divided into triangular segments, glabrous.

campanulate, 1.3–2.3 × 1.6–2.5 mm, lobes ovate to oblong, 0.5–0.7 mm, ciliate;

glands purple-red, oblong to trapezoidal, 0.5–0.7 × 0.8–1.2 mm, distal margins entire or crenulate.

Staminate flowers

10–12.

25–30.

Pistillate flowers

ovary puberulent on keels, styles 0.8–1.1 mm, 2-fid 1/2 to nearly entire length.

gynophore exserted 1.9–3.2 mm, calyxlike lobes triangular, 0.2–0.7 mm;

styles connate 1/4 length, 1.3–1.5 mm.

Capsules

broadly depressed-oblong to ovoid, 2.7–3.3 × 3.1–3.9 mm, puberulent (with appressed hairs usually concentrated on keels);

columella 1.9–2.5 mm.

ovoid-oblate, 5.2–5.6 × 6.6–8.3 mm, 3-lobed;

columella 3.9–4.1 mm.

Seeds

white to gray or light brown, ovoid, bluntly 4-angled in cross section, 1.9–2.5 × 1.4–1.7 mm, tuberculate, often with 2 transverse ridges;

caruncle 0.1 × 0.2 mm.

blackish to dark brown, ovoid to globose-ovoid, circular in cross section, 3.2–3.5 × 2.6–3.1 mm, smooth, base rounded to flattened, apex rounded, occasionally with low point.

Cyathial

arrangement: terminal cymose or dichasial branches usually 1–2, occasionally reduced to monochasia, 1–2-branched;

pleiochasial bracts 2–4, often whorled, wholly green or paler green at base, similar in shape and size to distal leaves or slightly narrower;

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

arrangement: terminal pleiochasial branches (2–)3, 5–13 cm, 3–7 times 2-branched;

pleiochasial bracts ovate to oblong, 17–31 × 8–15 mm, margins entire, apex acute or obtuse;

dichasial bracts ovate, 5–19 × 3–9 mm, margins entire, apex acute or obtuse;

axillary cymose branches 1–5.

Cyathia

peduncle 1–1.9 mm.

peduncle 3–9.2 mm (often exceeding subcyathial leaves).

Euphorbia exstipulata

Euphorbia telephioides

Phenology Flowering and fruiting summer–fall. Flowering and fruiting spring–fall.
Habitat Desert scrub, grasslands, mesquite savannas, oak and oak-juniper woodlands. Scrubby pine flatwoods, grasslands, disturbed areas, often in sandy soils.
Elevation 800–2000 m. (2600–6600 ft.) 0–20 m. (0–100 ft.)
Distribution
from FNA
AZ; CA; NM; TX; UT; WY; Mexico (Chihuahua, Coahuila, Durango, Guanajuato, San Luis Potosí, Sonora, Zacatecas)
[WildflowerSearch map]
[BONAP county map]
from FNA
FL
[BONAP county map]
Discussion

Euphorbia exstipulata is native from Texas to California and northern Mexico. The species was found once in the late nineteenth century in Wyoming but has not been re-collected there. Broad-leaved plants have been segregated as var. lata, but the variation in leaf shape is continuous and no varieties are formally recognized here.

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

Euphorbia telephioides, federally listed as threatened, is known only from Bay, Franklin, and Gulf counties in the Apalachicola region of the east-central Florida panhandle.

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

Source FNA vol. 12, p. 322. FNA vol. 12, p. 316.
Parent taxa Euphorbiaceae > Euphorbia > sect. Poinsettia Euphorbiaceae > Euphorbia > sect. Nummulariopsis
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. 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. 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. 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 E. exstipulata var. lata Galarhoeus telephioides
Name authority Engelmann: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 189. (1859) Chapman: Fl. South. U.S., 402. (1860)
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