Euphorbia vermiculata |
Euphorbia trachysperma |
|
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hairy sandmat, wormseed sandmat, wormseed spurge |
San Pedro River sandmat |
|
Habit | Herbs, annual or short-lived perennial, with slender, fibrous taproot. | Herbs, annual, with slender taproot. |
Stems | prostrate to ascending or erect, not mat forming, 10–35 cm, usually sparsely to moderately strigillose, pilose, or villous, rarely glabrate hairs sometimes in longitudinal lines. |
erect to ascending, 10–55 cm, glabrous. |
Leaves | opposite; stipules distinct or connate, triangular to narrowly triangular or laciniate into subulate to filiform divisions, 0.6–1.3 mm, glabrous or sparsely pilose; petiole 0.2–0.9 mm, glabrous, villous, or strigillose; blade ovate, oblong, or elliptic, often falcate, 5–18 × 3–9 mm, base asymmetric, one side rounded and other cordate, margins usually serrulate especially in distal 1/2, rarely nearly entire, apex acute or obtuse, surfaces not papillate, sparsely pilose, villous, or sericeous (especially near base), often glabrate (especially older leaves); 3–5-veined from base. |
opposite; stipules distinct, narrowly triangular and often divided into 3–5 subulate to filiform segments, 0.8–1.9 mm, glabrous; petiole 1.2–3.1 mm, glabrous; blade oblong, elliptic, or ovate, 12–43 × 3–14 mm, base subsymmetric to asymmetric, rounded, attenuate, or with one side hemicordate and other side rounded, margins usually serrulate, rarely entire on some leaves or portion of blade, apex obtuse to acute, surfaces often with red blotch in center, glabrous; pinnately veined, often only midvein conspicuous. |
Involucre | obconic, 0.7–1.1 × 0.5–0.8 mm, glabrous; glands (2–3)–4, red to reddish green, circular to oblong, 0.1 × 0.1–0.2 mm; appendages absent or white, turning pink with age, flabellate, oblong, circular, or forming narrow lunate border around margin of gland, 0.1–0.3 × 0.2–0.4 mm, distal margin entire or slightly lobed. |
oblong, campanulate, or funnel-shaped, 1.5–2.6 × 1.1–2.3 mm, glabrous; glands 4, green to yellowish or tinged with red, subcircular to oblong, 0.4–0.7 × 0.5–1 mm; appendages absent or white, often forming narrow rim or oblong to ovate, 0–0.8 × 1.2 mm, distal margin entire. |
Staminate flowers | 5–15. |
50–60. |
Pistillate flowers | ovary glabrous; styles 0.3–0.5 mm, 2-fid 1/2 length. |
ovary glabrous; styles 0.5–0.6 mm, 2-fid 1/2 length. |
Capsules | oblate to subglobose, cocci not elongated nor terminating in empty portion, 1.4–1.8 × 1.7–2.1 mm, glabrous; columella 1.1–1.5 mm. |
oblate, 2.4–3.2 × 3–3.5 mm, glabrous; columella 2.3–2.5 mm. |
Seeds | brown, gray, or almost black, ovoid to oblong, 3–4-angled in cross section, 1.1–1.4 × 0.7–0.8 mm, rugulose and sometimes also with low transverse ridges that do not interrupt abaxial keel. |
light brown, ovoid, 4-angled in cross section, abaxial keel well developed, 1.9–2.3 × 1.3–1.4 mm, finely dimpled and papillate. |
Cyathia | solitary at distal nodes or in small, cymose clusters at branch tips; peduncle 0.2–2.5 mm. |
solitary at distal nodes; peduncle 1.4–2.4 mm. |
Euphorbia vermiculata |
Euphorbia trachysperma |
|
Phenology | Flowering and fruiting spring–fall. | Flowering and fruiting late summer–early winter. |
Habitat | Juniper-oak woodlands, temperate deciduous forests, grasslands, pine forests, oak forests with sycamores, walnuts and alders, often in disturbed areas. | Desert scrub, desert grasslands, mesquite woodlands. |
Elevation | 0–2600 m. (0–8500 ft.) | 200–1200 m. (700–3900 ft.) |
Distribution |
AZ; CT; IL; IN; MA; MD; ME; MI; MN; NH; NJ; NM; NY; OH; PA; RI; VA; VT; WI; WV; NB; NS; ON; QC; Mexico; temperate deciduous forests; often in disturbed areas; walnuts and alders; oak forests with sycamores; pine forests; grasslands; Juniper-oak woodlands
|
AZ; Mexico (Baja California Sur, Sonora) |
Discussion | Euphorbia vermiculata has an interesting disjunct distribution; it ranges from central Mexico to Arizona and New Mexico, and is also present in the northeastern United States and southeastern Canada. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Euphorbia trachysperma may be expected in extreme southwestern New Mexico given the close proximity of some collections in southeastern Arizona. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 292. | FNA vol. 12, p. 291. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | Chamaesyce rothrockii, C. vermiculata, E. rothrockii | Chamaesyce trachysperma |
Name authority | Rafinesque: Amer. Monthly Mag. & Crit. Rev. 2: 206. (1818) | Engelmann: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 189. (1859) |
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