Euphorbia vermiculata |
Euphorbia polycarpa |
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hairy sandmat, wormseed sandmat, wormseed spurge |
smallseed sandmat |
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Habit | Herbs, annual or short-lived perennial, with slender, fibrous 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. |
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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. |
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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. |
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Staminate flowers | 5–15. |
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Pistillate flowers | ovary glabrous; styles 0.3–0.5 mm, 2-fid 1/2 length. |
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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. |
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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. |
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Cyathia | solitary at distal nodes or in small, cymose clusters at branch tips; peduncle 0.2–2.5 mm. |
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Euphorbia | polycarpa is a highly variable species distributed throughout the Baja California peninsula, eastern Sonora, and the arid southwestern United States from southwestern Arizona to southern Nevada and central California. |
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l | . |
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c | . |
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Wheeler | (1941) divided the species into seven varieties, the majority of which occur in Baja California Sur. |
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He | reported two of these for the United States: var. hirtella and var. polycarpa. |
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Variety | hirtella, as the name suggests, was applied to hairy plants. |
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However | , it is here treated as a synonym of var. polycarpa, because variation in pubescence shows no geographic segregation and ranges along a continuum from glabrous or sparsely to densely hairy, and because glabrous and hairy branches can occur on the same individual. |
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Euphorbia vermiculata |
Euphorbia polycarpa |
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Phenology | Flowering and fruiting spring–fall. | |
Habitat | Juniper-oak woodlands, temperate deciduous forests, grasslands, pine forests, oak forests with sycamores, walnuts and alders, often in disturbed areas. | |
Elevation | 0–2600 m. (0–8500 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
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AZ; CA; NV; nw Mexico
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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.) |
Varieties 5 (1 in the flora). Some of the varieties occurring in Mexico are highly divergent and appear to be sufficiently distinct to merit recognition as species. However, within the flora area, Euphorbia polycarpa is relatively uniform, and the only noteworthy variation involves the size of the involucral gland appendages. In the portion of the California Floristic Province occupied by E. polycarpa (Los Angeles, Orange, western Riverside, western San Diego, and Ventura counties) the appendages are conspicuously larger than those of plants throughout the remainder of its range in the southwestern United States (0.4–1.2 versus 0.1–0.3 mm). Large-appendaged plants are also common in Baja California and correspond well with the type collection. The taxonomic significance of this variation is not clear at this time, and the small-appendaged plants may merit segregation as an infraspecific taxon. However, no formal changes are proposed, awaiting a comprehensive review of the species throughout its range. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 292. | FNA vol. 12, p. 283. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Subordinate taxa | ||
Synonyms | Chamaesyce rothrockii, C. vermiculata, E. rothrockii | Chamaesyce polycarpa |
Name authority | Rafinesque: Amer. Monthly Mag. & Crit. Rev. 2: 206. (1818) | Bentham: Bot. Voy. Sulphur, 50. (1844) |
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