OregonFlora: Euphorbia glyptosperma vs. Euphorbia helioscopia

	Chamaesyce glyptosperma (synonym of Euphorbia glyptosperma)	Euphorbia helioscopia
	currugate-seeded spurge, ribseed sandmat, ridge-seeded spurge	mad woman's milk, wartweed
Habit	Plants annual; stems prostrate, 4–40 cm, glabrous; taprooted.	Herbs annual, 1–5 dm; stems,erect, glabrous to sparsely hairy.
Leaves	oblanceolate to elliptic or ovate, 3–10 mm, occasionally with central red spot; margins entire to shallowly toothed; tips rounded; surfaces glabrous; petioles 0.3–1 mm; stipules linear, often dissected, 1–1.5 mm.	alternate (upper leaves may be opposite), obovate to spatulate, 10–30 × 5–15 mm; margins toothed in at least upper 25%; entire below; tips rounded; surfaces glabrous, sessile.
Inflorescences	involucres 0.5–1 mm, glabrous; glands elliptic; gland appendages white.	involucres cone-shaped, 1–1.5 mm; glands not horned.
Flowers		styles divided less than halfway to base.
Fruits	ovoid, 1.5–2 mm, glabrous.	round, 2.5–3 mm.
Seeds	ovoid, 1–1.5 mm; cross-ridged.	ovoid, 1.5–2.5 mm, with reticulate pitting.

	Chamaesyce glyptosperma	Euphorbia helioscopia
Distribution	[WildflowerSearch map] [BONAP county map]	[WildflowerSearch map] [BONAP county map]
Discussion	Dry areas, roadsides. Flowering Jun–Sep. 0–1600 m. BW, Col, ECas, Lava, Owy, Sisk, WV. CA, ID, NV, WA; southern Canada and most of US except southeastern states, Mexico. Native.	Disturbed areas. Flowering Apr–Jul. 0–200 m. CR, WV. CA, WA; scattered throughout North America; Asia, Europe. Exotic. Euphorbia helioscopia is easily confused with E. spathulata. The former is an exotic species introduced from Eurasia, while E. spathulata is considered native. The most reliable characteristic separating these taxa is the size of the involucres.
Source	Flora of Oregon, volume 2, page 643 Stephen Meyers	Flora of Oregon, volume 2, page 645 Stephen Meyers
Sibling taxa	C. glyptosperma, C. maculata, C. prostrata, C. serpens, C. serpillifolia	E. crenulata, E. cyparissias, E. dentata, E. esula, E. lathyris, E. myrsinites, E. oblongata, E. peplus, E. spathulata
Synonyms	Euphorbia glyptosperma
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Euphorbia helioscopia

currugate-seeded spurge, ribseed sandmat, ridge-seeded spurge

mad woman's milk, wartweed

Habit

Plants annual; stems prostrate, 4–40 cm, glabrous; taprooted.

Herbs annual, 1–5 dm; stems,erect, glabrous to sparsely hairy.

Leaves

oblanceolate to elliptic or ovate, 3–10 mm, occasionally with central red spot;

margins entire to shallowly toothed;

tips rounded;

surfaces glabrous;

petioles 0.3–1 mm;

stipules linear, often dissected, 1–1.5 mm.

alternate (upper leaves may be opposite), obovate to spatulate, 10–30 × 5–15 mm;

margins toothed in at least upper 25%; entire below;

tips rounded;

surfaces glabrous, sessile.

Inflorescences

involucres 0.5–1 mm, glabrous;

glands elliptic;

gland appendages white.

involucres cone-shaped, 1–1.5 mm;

glands not horned.

Flowers

styles divided less than halfway to base.

Fruits

ovoid, 1.5–2 mm, glabrous.

round, 2.5–3 mm.

Seeds

ovoid, 1–1.5 mm; cross-ridged.

ovoid, 1.5–2.5 mm, with reticulate pitting.

Euphorbia helioscopia

Distribution

[WildflowerSearch map]

[BONAP county map]

[WildflowerSearch map]

[BONAP county map]

Discussion

Dry areas, roadsides. Flowering Jun–Sep. 0–1600 m. BW, Col, ECas, Lava, Owy, Sisk, WV. CA, ID, NV, WA; southern Canada and most of US except southeastern states, Mexico. Native.

Disturbed areas. Flowering Apr–Jul. 0–200 m. CR, WV. CA, WA; scattered throughout North America; Asia, Europe. Exotic.

Euphorbia helioscopia is easily confused with E. spathulata. The former is an exotic species introduced from Eurasia, while E. spathulata is considered native. The most reliable characteristic separating these taxa is the size of the involucres.

Source

Flora of Oregon, volume 2, page 643
Stephen Meyers

Flora of Oregon, volume 2, page 645
Stephen Meyers

Sibling taxa

C. glyptosperma, C. maculata, C. prostrata, C. serpens, C. serpillifolia