Euphorbia eriantha |
Euphorbia serrata |
|
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beetle spurge |
saw tooth spurge, saw-tooth or tooth or serrate spurge, serrate spurge |
|
Habit | Herbs, annual or perennial, with slender to thick, woody taproot. | Herbs, perennial, with thick rootstock. |
Stems | erect to ascending, 10–75 cm, glabrous or with scattered appressed hairs (especially near nodes); branches arcuate. |
erect, branched, 10–70 cm, glabrous. |
Leaves | alternate; petiole 0.1–0.4 mm, often indistinct, glabrous or sparsely pilose to shortly sericeous; blade linear to linear-elliptic, 20–55 × 1–3 mm, base attenuate, margins entire or with 2–4 inconspicuous teeth near apex, apex acute, abaxial surface pilose to shortly sericeous, adaxial surface usually glabrous, rarely pilose to shortly sericeous; only midvein conspicuous. |
petiole absent; blade lanceolate, ovate-lanceolate, linear, or linear-lanceolate, 10–70 × 2–20 mm, base acute or obtuse, margins irregularly serrate, apex acute to obtuse, surfaces glabrous; venation inconspicuous, only midvein prominent. |
Involucre | obconic, 2.1–2.6 × 1.3–2 mm, canescent; involucral lobes triangular, obscured by hairs; glands (2–)4–5, green to maroon, color often obscured by hairs, sessile and broadly attached, 0.5–0.6 × 0.5–0.6 mm, opening oblong to nearly circular, densely canescent; appendages petaloid, whitish, hoodlike, incurved and covering glands, 0.5–1 × 0.5–0.8 mm, divided into 5–12 fringed, subulate segments, densely canescent. |
campanulate, 2–4 × 1.2–3 mm, glabrous; glands 4–5, elliptic, ovate, or suborbiculate, 1.2–1.8 × 1.5–2.7 mm; horns absent or slightly divergent, 0–0.6 mm. |
Staminate flowers | 20–25. |
20–40. |
Pistillate flowers | ovary canescent; styles 0.9–1.5 mm, unbranched. |
ovary glabrous; styles 1–2 mm, 2-fid. |
Capsules | oblong to ovoid, 4.4–4.9 × 3.5–4.1 mm, canescent (often with interspersed glabrescent patches); columella 3.5–3.9 mm. |
subovoid, 4.5–6 × 4–5 mm, 3-lobed; cocci rounded, smooth occasionally slightly puncticulate, glabrous; columella 4–4.5 mm. |
Seeds | mottled black and gray or light brown, oblong or slightly ovoid, dorsiventrally compressed in cross section, 2.8–4.1 × 2–2.4 mm, irregularly pitted and tuberculate; caruncle 0.4–0.8 × 0.6–1.1 mm. |
grayish, cylindric, 2.5–3.1 × 1.7–2 mm, smooth or slightly dotted; caruncle subconic, lobed, 1–1.5 × 0.5–1 mm. |
Cyathial | arrangement: terminal cymose branches 1, 1–2-branched; pleiochasial bracts 2–3, opposite or whorled, wholly green, similar in shape and size to distal leaves; dichasial bracts similar in shape to distal leaves or often highly reduced. |
arrangement: terminal pleiochasial branches 3–5, each 1–3 times 2-branched; pleiochasial bracts ovate-lanceolate, usually shorter and wider than distal leaves; dichasial bracts distinct, ovate or deltate, base obtuse to cordate, margins irregularly dentate, apex acute, or obtuse, mucronate; axillary cymose branches 0–3. |
Cyathia | peduncle 1–1.9 mm. |
peduncle 1–5 mm. |
Euphorbia eriantha |
Euphorbia serrata |
|
Phenology | Flowering and fruiting year-round in response to sufficient rainfall. | Flowering and fruiting spring–fall. |
Habitat | Desert scrub on rocky slopes and along washes. | Waste places, disturbed sites, roadsides, fields, pastures. |
Elevation | 60–800 m. (200–2600 ft.) | 0–300 m. (0–1000 ft.) |
Distribution |
AZ; CA; NM; TX; Mexico (Baja California, Baja California Sur, Chihuahua, Coahuila, Durango, San Luis Potosí, Sonora)
|
CA; Europe; Atlantic Islands (Macaronesia) [Introduced in North America] |
Discussion | Euphorbia serrata, native to the western Mediterranean region of Europe and Macaronesia, is listed as a noxious weed by the state of California. In the flora area, it has been found in coastal counties from Sonoma to Monterey counties; attempts to eradicate it may have been successful. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 12, p. 321. | FNA vol. 12, p. 309. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Poinsettia | Euphorbiaceae > Euphorbia > subg. Esula |
Sibling taxa | ||
Synonyms | Galarhoeus serratus, Tithymalus serratus | |
Name authority | Bentham: Bot. Voy. Sulphur, 51. (1844) | Linnaeus: Sp. Pl. 1: 459. (1753) |
Web links |