OregonFlora: Euphorbia spathulata vs. Euphorbia maculata

	Euphorbia spathulata	Chamaesyce maculata (synonym of Euphorbia maculata)
	prairie spurge	prostrate spurge, spotted sandmat, spotted spurge
Habit	Herbs annual, 1–5(6) dm; stems, erect, glabrous.	Plants annual; stems prostrate, 5–50 cm, hairy; taprooted.
Leaves	alternate (upper leaves may be opposite), obovate to spatulate, 10–30 × 5–15 mm; margins toothed at least in upper 25%; entire below; tips rounded; surfaces glabrous, sessile.	linear-oblong to ovate-oblong, 5–15 mm, often with a central red spot; margins entire to shallowly toothed; tips rounded to acute; surfaces glabrous or hairy; petioles 0.5–1.5 mm; stipules slender, fringed, 0.3–0.9 mm.
Inflorescences	involucres cone- to bell-shaped, 2–3 mm; glands not horned.	involucres 0.5–1 mm; hairy; glands elliptic; gland appendages white to pink.
Flowers	styles divided nearly to base.
Fruits	round, 2–2.5 mm.	ovoid, 1–1.5 mm; hairy.
Seeds	ovoid to ellipsoid, 1–2 mm, with reticulate pitting.	ovoid to oblong, 0.7–1.3 mm, usually wrinkled, occasionally smooth.

	Euphorbia spathulata	Chamaesyce maculata
Distribution	[WildflowerSearch map] [BONAP county map]	[WildflowerSearch map] [BONAP county map]
Discussion	Disturbed areas. Flowering Apr–Aug. 100–1000 m. BW, Sisk, WV. CA, ID, WA; throughout most of US, Ontario, Mexico. Native. See also E. helioscopia.	Sidewalks, cracks in pavement, roadsides, disturbed areas. Flowering Jun–Sep. 0–1300 m. Casc, CR, ECas, Est, Lava, Sisk, WV. CA, ID, NV, WA; throughout North America except northern Canada. Native. Some sources speculate this species was originally native to eastern North America and was later introduced in other parts of the continent. Without definitive proof, however, we currently consider this species native.
Source	Flora of Oregon, volume 2, page 646 Stephen Meyers	Flora of Oregon, volume 2, page 643 Stephen Meyers
Sibling taxa	E. crenulata, E. cyparissias, E. dentata, E. esula, E. helioscopia, E. lathyris, E. myrsinites, E. oblongata, E. peplus	C. glyptosperma, C. maculata, C. prostrata, C. serpens, C. serpillifolia
Synonyms	Euphorbia dictyosperma	Chamaesyce supina, Euphorbia maculata, Euphorbia supina
Web links	Local floras: 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

Chamaesyce maculata

(synonym of Euphorbia maculata)

prairie spurge

prostrate spurge, spotted sandmat, spotted spurge

Habit

Herbs annual, 1–5(6) dm; stems, erect, glabrous.

Plants annual; stems prostrate, 5–50 cm, hairy; taprooted.

Leaves

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

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

tips rounded;

surfaces glabrous, sessile.

linear-oblong to ovate-oblong, 5–15 mm, often with a central red spot;

margins entire to shallowly toothed;

tips rounded to acute;

surfaces glabrous or hairy;

petioles 0.5–1.5 mm;

stipules slender, fringed, 0.3–0.9 mm.

Inflorescences

involucres cone- to bell-shaped, 2–3 mm;

glands not horned.

involucres 0.5–1 mm; hairy;

glands elliptic;

gland appendages white to pink.

Flowers

styles divided nearly to base.

Fruits

round, 2–2.5 mm.

ovoid, 1–1.5 mm; hairy.

Seeds

ovoid to ellipsoid, 1–2 mm, with reticulate pitting.

ovoid to oblong, 0.7–1.3 mm, usually wrinkled, occasionally smooth.

Chamaesyce maculata

Distribution

[WildflowerSearch map]

[BONAP county map]

[WildflowerSearch map]

[BONAP county map]

Discussion

Disturbed areas. Flowering Apr–Aug. 100–1000 m. BW, Sisk, WV. CA, ID, WA; throughout most of US, Ontario, Mexico. Native.

See also E. helioscopia.

Sidewalks, cracks in pavement, roadsides, disturbed areas. Flowering Jun–Sep. 0–1300 m. Casc, CR, ECas, Est, Lava, Sisk, WV. CA, ID, NV, WA; throughout North America except northern Canada. Native.

Some sources speculate this species was originally native to eastern North America and was later introduced in other parts of the continent. Without definitive proof, however, we currently consider this species native.

Source

Flora of Oregon, volume 2, page 646
Stephen Meyers

Flora of Oregon, volume 2, page 643
Stephen Meyers

Sibling taxa