Euphorbia thymifolia |
Euphorbia falcata |
|
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gulf sandmat |
sickle spurge |
|
Habit | Herbs, annual or perennial, with taproot. | Herbs, annual, with taproot. |
Stems | prostrate, mat-forming, 15–30 cm, strigose to strigose-tomentulose. |
erect, unbranched or branched, 5–20 cm, glabrous. |
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 obovate, linear-oblong, or spatulate, 2–20 × 2–10 mm, base cuneate or attenuate, margins entire, apex acute, obtuse, emarginate, or mucronate, surfaces glabrous; venation usually inconspicuous, sometimes 3-nerved from base, midvein prominent. |
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. |
cupulate, 0.5–1.2 × 0.6–1.3 mm, glabrous; glands 4, elliptic to orbiculate, 0.2–0.3 × 0.3–0.8 mm; horns usually absent, occasionally divergent, 0.5–1.2 mm. |
Staminate flowers | 3–5. |
6–10. |
Pistillate flowers | ovary densely strigose; styles 0.4–0.5 mm, 2-fid 1/2 length. |
ovary pilose only at base, styles 0.9–1.1 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. |
subovoid, 2–3 × 1.8–3 mm, slightly lobed; cocci rounded, smooth, glabrous or slightly pilose along abaxial region; columella 1.1–1.8 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, whitish, or light brownish, ovoid, 1.2–1.8 × 0.7–1.1 mm, transversally sulcate; caruncle subglobose to subconic, 0.2–0.5 × 0.2–0.5 mm. |
Cyathia | usually in small, cymose clusters on congested, axillary branches; peduncle (0–)0.1–0.3 mm. |
peduncle 0–2 mm. |
Cyathial | arrangement: terminal pleiochasial branches 2–5, each 2–6 times 2-branched; pleiochasial bracts similar in shape to but usually shorter and wider than distal leaves; dichasial bracts distinct, widely ovate, rhombic, or suborbiculate, imbricate, base cordate, truncate or cuneate, margins finely denticulate, apex acute or obtuse, strongly mucronate; axillary cymose branches 0–10. |
|
Euphorbia thymifolia |
Euphorbia falcata |
|
Phenology | Flowering and fruiting midsummer–early fall. | Flowering and fruiting spring–summer. |
Habitat | Disturbed areas, often near salt water. | Waste places, roadsides. |
Elevation | 0–20 m. (0–100 ft.) | 0–1600 m. (0–5200 ft.) |
Distribution |
FL; LA; Mexico; South America; West Indies [Introduced in Asia, tropical Africa, Australia] |
KY; MD; OH; PA; TN; VA; WV; s Europe; c Europe; w Asia; c Asia; s Asia; n Africa [Introduced in North America; introduced also in South America (Chile)] |
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.) |
|
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 falcatus |
Name authority | Linnaeus: Sp. Pl. 1: 454. (1753) | Linnaeus: Sp. Pl. 1: 456. (1753) |
Web links |