Euphorbia thymifolia |
Euphorbia dendroides |
|
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gulf sandmat |
tree spurge |
|
Habit | Herbs, annual or perennial, with taproot. | Shrubs, dendroid, with large rootstock. |
Stems | prostrate, mat-forming, 15–30 cm, strigose to strigose-tomentulose. |
erect, stout, densely branched, to 200 cm, glabrous, bark usually reddish and glossy toward tip of branches. |
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. |
petiole absent; blade linear-lanceolate to oblong-lanceolate, 20–65 × 3–8 mm, base attenuate, margins entire, apex obtuse to acute, sometimes mucronulate, surfaces glabrous; venation pinnate, midvein prominent, base attenuate. |
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. |
broadly turbinate to hemispheric, 3–4 × 3.5–3.8 mm, glabrous; glands 4, suborbiculate to subtrapezoidal, 1–1.5 × 1.2–1.8 mm, sometimes irregularly lobed; horns absent. |
Staminate flowers | 3–5. |
20–25. |
Pistillate flowers | ovary densely strigose; styles 0.4–0.5 mm, 2-fid 1/2 length. |
ovary glabrous; styles 2.4–3 mm, 2-fid. |
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. |
subglobose, 4–5.5 × 4–6.5 mm, deeply lobed; cocci laterally compressed, smooth, glabrous; columella 3–4 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. |
grayish or blackish, ovoid and strongly laterally compressed, 3–3.5 × 1.5–2 mm, smooth; caruncle semirounded and laterally compressed, 1.2–1.4 × 0.8–1.8 mm. |
Cyathia | usually in small, cymose clusters on congested, axillary branches; peduncle (0–)0.1–0.3 mm. |
peduncle absent. |
Cyathial | arrangement: terminal pleiochasial branches 4–8, unbranched or 1–2-times 2-branched; pleiochasial bracts similar in shape to but usually shorter and wider than distal leaves; dichasial bracts distinct, yellowish, broadly ovate, orbiculate, rhombic, or reniform, base obtuse, margins entire, apex obtuse, sometimes mucronulate; axillary pleiochasial absent. |
|
Euphorbia thymifolia |
Euphorbia dendroides |
|
Phenology | Flowering and fruiting midsummer–early fall. | Flowering and fruiting fall–spring. |
Habitat | Disturbed areas, often near salt water. | Coastal plains and basins, hillsides. |
Elevation | 0–20 m. (0–100 ft.) | 0–500 m. (0–1600 ft.) |
Distribution |
FL; LA; Mexico; South America; West Indies [Introduced in Asia, tropical Africa, Australia] |
CA; Europe; n Africa [Introduced in North America] |
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 dendroides is native to the Mediterranean region. In the flora area, the species is known from Los Angeles, Santa Barbara, and Ventura counties. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 291. | FNA vol. 12, p. 302. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > subg. Esula |
Sibling taxa | ||
Synonyms | Chamaesyce thymifolia | Tithymalus dendroides |
Name authority | Linnaeus: Sp. Pl. 1: 454. (1753) | Linnaeus: Sp. Pl. 1: 462. (1753) |
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