Euphorbia thymifolia |
Euphorbia jaegeri |
|
---|---|---|
gulf sandmat |
orocopia mountains spurge |
|
Habit | Herbs, annual or perennial, with taproot. | Shrubs, with woody rootstock. |
Stems | prostrate, mat-forming, 15–30 cm, strigose to strigose-tomentulose. |
ascending, diffusely and intricately branched, 15–25 cm, usually puberulent to shortly hirsute, sometimes glabrate, bark grayish. |
Leaves | opposite; stipules distinct or slightly connate at base, linear-subulate, entire or slightly parted, 0.9–1.2 mm, strigose-tomentulose; petiole 0.5–1 mm, sparsely strigose-tomentulose; blade broadly elliptic to narrowly oblong or ovate-lanceolate, 3–10 × 1.8–5 mm, base asymmetric, one side usually angled or rounded and the other truncate and expanded into small, rounded auricle, margins serrate (larger leaves) to serrulate (smaller leaves), apex blunt to acute, abaxial surface sparsely tomentulose to glabrate, adaxial surface glabrate; palmately veined at base, pinnate distally. |
opposite; stipules distinct or connate, subulate, 0.3–0.5 mm, puberulent; petiole 0.7–1.1 mm, puberulent to shortly hirsute; blade ovate or elliptic, 3–9 × 1.5–5 mm, base symmetric to slightly asymmetric, rounded to cuneate, margins entire, apex usually obtuse, sometimes acute, surfaces puberulent to shortly hirsute; 3-veined from base, often only midvein conspicuous. |
Involucre | broadly obconic, becoming distended and distorted by base of partially included capsule, 0.4–0.8 × 0.3–0.5 mm, strigose; glands 4, red, slightly concave, ± unequal, subcircular to broadly oval, 0.1–0.2 × 0.2–0.3 mm; appendages white to pink, usually unequal, occasionally ± equal at distal nodes, elongated toward sinus, sometimes rudimentary, 0.1–0.4 × 0.1–0.3 mm, distal margin entire or crenulate. |
obconic to campanulate, 1.2–1.8 × 1.1–1.4 mm, puberulent to shortly hirsute; glands 4, yellow to pinkish, elliptic to oblong, 0.3 × 0.4–0.5 mm; appendages white to pink, 0.2–0.7 × 0.6–1.2 mm, irregularly divided from halfway to nearly base into 4–8 triangular to subulate segments, segments entire. |
Staminate flowers | 3–5. |
25–30. |
Pistillate flowers | ovary densely strigose; styles 0.4–0.5 mm, 2-fid 1/2 length. |
ovary canescent; styles 0.3–0.4 mm, 2-fid entire length. |
Capsules | conic to truncate-ovoid, scarcely exserted from involucre, base often remaining inside involucre and splitting one side of it during maturation, 0.9–1.2 × 1–1.2 mm, sparsely to moderately strigose; columella 0.6–1 mm. |
oblate, 1.7–2.3 × 1.8–2.7 mm, puberulent; columella 1.4–2 mm. |
Seeds | white, tan underneath coat, ovoid to narrowly ovoid, sharply 4-angled in cross section, 0.8–0.9 × 0.4–0.6 mm, with 4 low transverse ridges often slightly extending into angles, not sulcate. |
tan to grayish, narrowly oblong-ovoid, ± 3–4-angled in cross section, 1.4–1.5 × 0.7–0.9 mm, irregularly dimpled or with faint transverse ridges that do not interrupt abaxial keel. |
Cyathia | usually in small, cymose clusters on congested, axillary branches; peduncle (0–)0.1–0.3 mm. |
solitary at distal nodes; peduncle 0.5–1.7 mm. |
Euphorbia thymifolia |
Euphorbia jaegeri |
|
Phenology | Flowering and fruiting midsummer–early fall. | Flowering and fruiting fall–spring. |
Habitat | Disturbed areas, often near salt water. | Desert scrub, hillsides, arroyos, primarily in rock crevices. |
Elevation | 0–20 m. (0–100 ft.) | 600–900 m. (2000–3000 ft.) |
Distribution |
FL; LA; Mexico; South America; West Indies [Introduced in Asia, tropical Africa, Australia] |
CA |
Discussion | Euphorbia thymifolia is a widespread tropical and subtropical weed. It is not certain where the species is native, but most likely it originated in the New World and then became widespread in the rest of the tropics. Euphorbia thymifolia is present in the flora area in southern Florida and coastal Louisiana, where it is likely adventive. Euphorbia thymifolia is generally similar to E. maculata but is characterized by its short pistillate pedicels and non-exserted capsules that remain largely enclosed by the involucre and by its unequal involucral gland appendages. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Euphorbia jaegeri is known only from the Orocopia Mountains of Riverside County and the Bristol and Marble Mountains of San Bernardino County. The species is one of few shrubby species of sect. Anisophyllum in the flora area. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 291. | FNA vol. 12, p. 273. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | Chamaesyce thymifolia | |
Name authority | Linnaeus: Sp. Pl. 1: 454. (1753) | V. W. Steinmann & J. M. André: Aliso 30: 1, figs. 1–4. (2012) |
Web links |
|