Euphorbia terracina |
Euphorbia roemeriana |
|
---|---|---|
carnation spurge, Geraldton carnation weed, terracina spurge |
Roemer's spurge |
|
Habit | Herbs, perennial or biennial, with taproot. | Herbs, annual, with taproot. |
Stems | erect, unbranched or branched, 10–100 cm, glabrous. |
erect, occasionally decumbent at base, branched, 15–30 cm, glabrous. |
Leaves | petiole absent; blade linear, linear-lanceolate, oblong-elliptic, or obovate, 4–50 × 2–10 mm, base obtuse or truncate, margins finely serrulate, apex acute, obtuse, or truncate, sometimes mucronulate, surfaces glabrous; venation inconspicuous, only midvein prominent. |
petiole 2–5 mm; blade oblanceolate to obovate, 5–20 × 5–10 mm (larger leaves in distal portion of stem), base cuneate to attenuate, margins entire, apex rounded, surfaces glabrous; venation pinnate. |
Involucre | cupulate to slightly turbinate, 1.1–2 × 1.3–1.5 mm, glabrous or puberulent; glands 4, elliptic to trapezoidal, 0.6–0.8 × 1–2 mm; horns slightly convergent to divergent, 1–2 mm. |
campanulate, 1.5–2 × 1–1.6 mm, glabrous; glands 4, elliptic to trapezoidal, 0.4–0.6 × 0.7–1.2 mm; horns slightly convergent, 0.1–0.3 mm. |
Staminate flowers | 15–20. |
10–12. |
Pistillate flowers | ovary glabrous; styles 1–1.8 mm, 2-fid. |
ovary glabrous; styles 0.6–1 mm, 2-fid. |
Capsules | depressed-globose, 2.5–3 × 3–4.5 mm, deeply 3-lobed; cocci rounded to subangular, smooth, glabrous; columella 1.9–2.3 mm. |
subglobose, 2–2.5 × 2.4–3 mm, slightly lobed; cocci rounded, smooth, glabrous; columella 1.5–1.8 mm. |
Seeds | pale gray, subovoid, 1.6–2.4 × 1.3–1.8 mm, smooth; caruncle boat-shaped, 0.4–0.6 × 0.4–0.6 mm. |
brown, oblong-ovoid, 1.6–1.8 × 1.4–1.5 mm, with scattered, deep and broad pits; caruncle conic, reniform, 0.3–0.4 × 0.4–0.6 mm. |
Cyathial | arrangement: terminal pleiochasial branches 2–5, each 1–5 times 2-branched; pleiochasial bracts lanceolate, elliptic or ovate, similar in size to distal leaves; dichasial bracts distinct, ovate to subreniform, base cuneate to cordate, margins finely serrulate, apex acute, obtuse, or rounded, sometimes mucronulate or cuspidate; axillary cymose branches 0–7. |
arrangement: terminal pleiochasial branches 3, 1–4 times 2-branched; pleiochasial bracts ovate to oblong, similar in size to distal leaves; dichasial bracts connate 1/2 length, reniform to semicircular, base truncate to perfoliate, margins entire, apex rounded to obtuse; axillary cymose branches 0–3. |
Cyathia | peduncle 1–3 mm. |
peduncle 0–0.9 mm. |
Euphorbia terracina |
Euphorbia roemeriana |
|
Phenology | Flowering and fruiting spring–summer. | Flowering and fruiting spring. |
Habitat | Edges of cultivated fields and woodlands, roadsides, waste areas, pastures, coastal bluffs, dunes, riparian areas. | Rich calcareous soils, creek canyons. |
Elevation | 0–300 m. (0–1000 ft.) | 100–300 m. (300–1000 ft.) |
Distribution |
CA; Europe [Introduced in North America; introduced also in Mexico, s Africa, Australia]
|
TX |
Discussion | Euphorbia terracina is native to the Mediterranean region of Europe. This species is invasive and spreading rapidly, displacing native coastal scrub in southern California, and has been listed as a noxious weed by that state. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
D. S. Correll and M. C. Johnston (1970) suggested that Euphorbia roemeriana, which is restricted to the eastern part of the Edwards Plateau, is the southern counterpart of E. commutata, to which it is morphologically very similar. However, molecular phylogenetic analyses indicate that it is most closely related to E. austrotexana and E. longicruris (J. A. Peirson et al. 2014). Euphorbia roemeriana can be distinguished from E. commutata and several of the other small, annual species of subg. Esula by its consistently connate dichasial bracts. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 310. | FNA vol. 12, p. 308. |
Parent taxa | Euphorbiaceae > Euphorbia > subg. Esula | Euphorbiaceae > Euphorbia > subg. Esula |
Sibling taxa | ||
Synonyms | Tithymalus terracinus | Tithymalus roemerianus |
Name authority | Linnaeus: Sp. Pl. ed. 2, 1: 654. (1762) | Scheele: Linnaea 22: 151. (1849) |
Web links |