OregonFlora: Euphorbia glyptosperma vs. Euphorbia serpillifolia

	Chamaesyce glyptosperma (synonym of Euphorbia glyptosperma)	Chamaesyce serpillifolia (synonym of Euphorbia serpillifolia)
	currugate-seeded spurge, ribseed sandmat, ridge-seeded spurge	thyme-leaved spurge, thymeleaf sandmat
Habit	Plants annual; stems prostrate, 4–40 cm, glabrous; taprooted.	Plants annual; stems prostrate to ascending, 5–40 cm, glabrous, sometimes glaucous; taprooted.
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.	oblanceolate to oblong, 3–15 mm, occasionally with a central red spot; margins entire to shallowly toothed; tips rounded; surfaces glabrous; petioles 0.5–1.5 mm; stipules slender and entire to linear and dissected, 1–1.5 mm.
Inflorescences	involucres 0.5–1 mm, glabrous; glands elliptic; gland appendages white.	involucres 0.5–1 mm, glabrous; glands elliptic; gland appendages white.
Fruits	ovoid, 1.5–2 mm, glabrous.	spherical, 1–2 mm, glabrous.
Seeds	ovoid, 1–1.5 mm; cross-ridged.	ovoid, 0.9–1.3 mm; smooth to wrinkled.

	Chamaesyce glyptosperma	Chamaesyce serpillifolia
Distribution	[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.	Usually dry places but sometimes in wet areas, roadsides, disturbed areas. Flowering Jun–Sep. 0–1900 m. BR, BW, Casc, Col, ECas, Lava, Owy, Sisk, WV. CA, ID, NV, WA; southern Canada, most of US except southeast and parts of northeast, Mexico. Native. In California, some plants of this species have hairy stems, involucres, and fruits. These plants are accepted by some authorities as C. s. ssp. hirtula (ours, in turn, would be C. s. ssp. serpillifolia). Given the already small morphological differences between our species of Chamaesyce, we have chosen not to recognize the subspecies.
Source	Flora of Oregon, volume 2, page 643 Stephen Meyers	Flora of Oregon, volume 2, page 643 Stephen Meyers
Sibling taxa	C. glyptosperma, C. maculata, C. prostrata, C. serpens, C. serpillifolia	C. glyptosperma, C. maculata, C. prostrata, C. serpens, C. serpillifolia
Synonyms	Euphorbia glyptosperma	Chamaesyce serpillifolia ssp. serpillifolia, Euphorbia serpillifolia, Euphorbia serpillifolia ssp. serpillifolia
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: CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Chamaesyce serpillifolia

(synonym of Euphorbia serpillifolia)

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

thyme-leaved spurge, thymeleaf sandmat

Habit

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

Plants annual; stems prostrate to ascending, 5–40 cm, glabrous, sometimes glaucous; taprooted.

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.

oblanceolate to oblong, 3–15 mm, occasionally with a central red spot;

margins entire to shallowly toothed;

tips rounded;

surfaces glabrous;

petioles 0.5–1.5 mm;

stipules slender and entire to linear and dissected, 1–1.5 mm.

Inflorescences

involucres 0.5–1 mm, glabrous;

glands elliptic;

gland appendages white.

involucres 0.5–1 mm, glabrous;

glands elliptic;

gland appendages white.

Fruits

ovoid, 1.5–2 mm, glabrous.

spherical, 1–2 mm, glabrous.

Seeds

ovoid, 1–1.5 mm; cross-ridged.

ovoid, 0.9–1.3 mm; smooth to wrinkled.

Chamaesyce serpillifolia

Distribution

[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.

Usually dry places but sometimes in wet areas, roadsides, disturbed areas. Flowering Jun–Sep. 0–1900 m. BR, BW, Casc, Col, ECas, Lava, Owy, Sisk, WV. CA, ID, NV, WA; southern Canada, most of US except southeast and parts of northeast, Mexico. Native.

In California, some plants of this species have hairy stems, involucres, and fruits. These plants are accepted by some authorities as C. s. ssp. hirtula (ours, in turn, would be C. s. ssp. serpillifolia). Given the already small morphological differences between our species of Chamaesyce, we have chosen not to recognize the subspecies.

Source

Flora of Oregon, volume 2, page 643
Stephen Meyers

Sibling taxa

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

Synonyms

Euphorbia glyptosperma

Chamaesyce serpillifolia ssp. serpillifolia, Euphorbia serpillifolia, Euphorbia serpillifolia ssp. serpillifolia

Web links