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pillpod sandmat, pillpod spurge

sickle spurge

Habit Herbs, annual or perennial, with slender to thickened taproot. Herbs, annual, with taproot.
Stems

usually erect to ascending, rarely prostrate or decumbent, 10–50(–75) cm, usually both strigillose and hirsute.

erect, unbranched or branched, 5–20 cm, glabrous.

Leaves

opposite;

stipules usually distinct, rarely connate at base, undivided or divided into 2–4 narrowly deltate to linear-subulate segments, 0.5–1.8(–2.9) mm, pilose, often with light-colored, minute circular glands at base;

petiole 1–3 mm, usually both strigillose and hirsute;

blade ovate to rhombic, 7–43 × 3–18 mm, base strongly asymmetric, one side rounded or slightly cordate to truncate, the other cuneate to attenuate, margins serrulate to double serrulate, apex acute, surfaces often with red spot in center, usually strigose to hirtellous, rarely glabrescent; 3–5-veined from base.

petiole absent;

blade obovate, linear-oblong, or spatulate, 2–20 × 2–10 mm, base cuneate or attenuate, margins entire, apex acute, obtuse, emarginate, or mucronate, surfaces glabrous;

venation usually inconspicuous, sometimes 3-nerved from base, midvein prominent.

Involucre

obconic, 0.6–1.2 × 0.4–0.9 mm, strigillose;

glands 4, greenish to pink, circular, oblong, or reniform, 0.1–0.2 × 0.1–0.2 mm;

appendages white to pink, flabellate, subcircular, or transversely oblong, rarely absent, (0–)0.1–0.6 × (0–)0.1–0.7 mm, distal margin usually entire, rarely slightly lobed.

cupulate, 0.5–1.2 × 0.6–1.3 mm, glabrous;

glands 4, elliptic to orbiculate, 0.2–0.3 × 0.3–0.8 mm;

horns usually absent, occasionally divergent, 0.5–1.2 mm.

Staminate flowers

2–8.

6–10.

Pistillate flowers

ovary strigillose, often canescent when young;

styles 0.2–0.6 mm, 2-fid 1/2 length.

ovary pilose only at base, styles 0.9–1.1 mm, 2-fid.

Capsules

subglobose to slightly oblate, 1–1.3 × 1.1–1.6 mm, strigillose;

columella 0.7–1 mm.

subovoid, 2–3 × 1.8–3 mm, slightly lobed;

cocci rounded, smooth, glabrous or slightly pilose along abaxial region;

columella 1.1–1.8 mm.

Seeds

brownish red to orange or pink, narrowly ovoid, 4-angled in cross section, 0.7–0.9 × 0.5–0.7 mm, usually rugulose or with 3–6 low transverse ridges, rarely nearly smooth.

grayish, whitish, or light brownish, ovoid, 1.2–1.8 × 0.7–1.1 mm, transversally sulcate;

caruncle subglobose to subconic, 0.2–0.5 × 0.2–0.5 mm.

Cyathia

in dense, axillary and terminal, capitate glomerules, with reduced, bractlike leaves subtending cyathia, axillary glomerules either sessile or at tips of elongated, leafless stalks;

peduncle 0.4–2.1 mm.

peduncle 0–2 mm.

Cyathial

arrangement: terminal pleiochasial branches 2–5, each 2–6 times 2-branched;

pleiochasial bracts similar in shape to but usually shorter and wider than distal leaves;

dichasial bracts distinct, widely ovate, rhombic, or suborbiculate, imbricate, base cordate, truncate or cuneate, margins finely denticulate, apex acute or obtuse, strongly mucronate;

axillary cymose branches 0–10.

Euphorbia hirta

Euphorbia falcata

Phenology Flowering and fruiting year-round. Flowering and fruiting spring–summer.
Habitat Disturbed areas, roadsides, vacant lots, desert grasslands, mesquite woodlands, riparian forests with cottonwoods and willows, flood plain forests, pinelands, deciduous forests. Waste places, roadsides.
Elevation 0–1500 m. (0–4900 ft.) 0–1600 m. (0–5200 ft.)
Distribution
from FNA
AL; AR; AZ; CA; FL; GA; LA; MS; NC; NM; NY; SC; TX; Mexico; Central America; South America; West Indies; Bermuda [Introduced in North America; introduced also in Europe, Asia, Africa, Australia]
[WildflowerSearch map]
[BONAP county map]
from FNA
KY; MD; OH; PA; TN; VA; WV; s Europe; c Europe; w Asia; c Asia; s Asia; n Africa [Introduced in North America; introduced also in South America (Chile)]
[BONAP county map]
Discussion

Euphorbia hirta is a widespread weed that is distributed throughout tropical and subtropical regions of the world. It is probably native to at least central Mexico, and its native range possibly extends from South America to the southern United States. In many places within the flora area the species is certainly introduced, and it has been recorded as a waif from several states (for example, Maryland, Michigan, and Virginia). Euphorbia pilulifera Linnaeus, a rejected name that is a heterotypic synonym of the Asian E. parviflora Linnaeus, has been misapplied to North American material of E. hirta in the past.

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

Source FNA vol. 12, p. 271. FNA vol. 12, p. 302.
Parent taxa Euphorbiaceae > Euphorbia > sect. Anisophyllum 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. 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. 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. 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 Chamaesyce gemella, C. hirta, E. gemella Tithymalus falcatus
Name authority Linnaeus: Sp. Pl. 1: 454. (1753) Linnaeus: Sp. Pl. 1: 456. (1753)
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