Euphorbia lathyris |
Euphorbia bombensis |
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caper spurge, euphorbe épurge, gopher plant, gopher spurge, mole plant |
Dixie sandmat, southern seaside spurge |
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Habit | Herbs, annual or biennial, with taproot. | Herbs, usually annual, rarely perennial, with taproot. |
Stems | erect, unbranched or branched, 200 cm, glabrous, glaucous. |
prostrate or slightly ascending, 10–40 cm, glabrous. |
Leaves | opposite, decussate; petiole absent; blade linear to oblong-lanceolate, 30–120 × 3–25 mm, base acute, rounded, cordate or clasping, margins entire, apex acute or subobtuse, sometimes mucronate, surfaces glabrous, abaxial ± glaucous; venation pinnate, midvein prominent. |
opposite; stipules distinct, linear-subulate, usually divided into 3 linear segments, 1–2 mm, glabrous; petiole 1–2 mm, glabrous; blade oblong or elliptic-oblong, 4–15 × 2–3 mm, base asymmetric to nearly symmetric, obtuse, margins entire, apex acute to mucronate, surfaces green to reddish flushed, glabrous; only midvein conspicuous. |
Involucre | campanulate, 1.2–2.3 × 1.4–2.5 mm, glabrous; glands 4, elliptic, 0.3–0.6 × 1–1.3 mm; horns divergent, thick, tips rounded, dilated, 0.5–1.4 mm. |
obconic-campanulate, 1.2–1.6 × 1.5–1.7 mm, glabrous; glands 4, green to red, slightly concave, elliptic, oblong, or subcircular, 0.3–0.5 × 0.4–0.6 mm; appendages white or pink, semilunate, fringing edge of gland, sometimes rudimentary, (0–)0.1–0.5(–0.7) × 0.5–0.8 mm, distal margin crenate to entire. |
Staminate flowers | 25–30. |
5–16. |
Pistillate flowers | ovary glabrous; styles 0.7–2.2 mm, 2-fid. |
ovary glabrous; styles 0.2–0.3 mm, 2-fid 1/2 length. |
Capsules | depressed-globose, 9–12 × 12–16 mm, deeply 3-lobed, tardily dehiscent and appearing indehiscent, mesocarp spongy; cocci rounded, smooth, glabrous; columella 4–5.2 mm. |
broadly ovoid, 2–2.1 × 2.3–2.5 mm, glabrous; columella 1.5–2 mm. |
Seeds | brownish or blackish, oblong, 4.5–6 × 3–4.2 mm, rugose, irregularly reticulate; caruncle substipitate, hat-shaped, 1.6–2 × 1.2–1.5 mm. |
ashy white, plumply ovoid, terete to bluntly subangled in cross section, 1.5–1.9 × 1–1.2 mm, smooth or minutely pitted, with smooth brown line from top to bottom on adaxial side. |
Cyathial | arrangement: terminal pleiochasial branches 2–4, each 1–2 times 2-branched; pleiochasial bracts cordate-lanceolate, shorter and wider than distal leaves; dichasial bracts distinct, ovate-oblong to lanceolate, base subcordate, margins entire, apex acute; axillary cymose branches 0–10. |
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Cyathia | peduncle 0–0.5 mm. |
solitary or in small, cymose clusters at distal nodes; peduncle 0.5–3 mm. |
Euphorbia lathyris |
Euphorbia bombensis |
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Phenology | Flowering and fruiting winter–fall. | Flowering and fruiting spring–fall. |
Habitat | Roadsides, cultivated fields, stream banks, waste places. | Coastal dunes and sandy habitats. |
Elevation | 0–1800 m. (0–5900 ft.) | 0–30 m. (0–100 ft.) |
Distribution |
AZ; CA; CT; ID; IL; MA; MD; MT; NC; OH; OR; PA; SC; TN; TX; VA; WA; WV; BC; ON; QC; Europe; Asia; Africa [Introduced in North America; introduced also in Mexico, South America, Australia]
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AL; FL; GA; LA; MS; NC; SC; TX; VA; Mexico; Central America; n South America (Venezuela)
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Discussion | Euphorbia lathyris is most likely native to the central and eastern Mediterranean region, but it is widely cultivated and often locally escaped in temperate regions worldwide, as in the flora area. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Euphorbia bombensis is similar and closely related to E. cumulicola, E. geyeri, and E. polygonifolia. It differs notably from E. polygonifolia in its smaller, plumply ovoid seeds. L. C. Wheeler (1941) suggested that where E. bombensis and E. polygonifolia are sympatric, E. bombensis grows farther away from the shore. Euphorbia bombensis is usually distinguished from E. cumulicola by the latter's smaller, isomorphic leaves that lack any fleshiness, smaller seeds, and diffuse growth habit. Euphorbia bombensis differs from E. geyeri in its usually shorter, less conspicuous involucral gland appendages and its geographic restriction to the coastal plain. However, Wheeler pointed out that plants of E. bombensis from Texas have more or less conspicuous involucral gland appendages. Examination of specimens confirmed that E. bombensis occasionally has conspicuous involucral gland appendages, and because of this, E. bombensis and E. geyeri are difficult to distinguish in Texas. This clade of closely related, sand and dune specialists requires further study. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 304. | FNA vol. 12, p. 261. |
Parent taxa | Euphorbiaceae > Euphorbia > subg. Esula | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | Galarhoeus lathyris, Tithymalus lathyris | Chamaesyce ammannioides, C. bombensis, C. ingallsii, E. ammannioides |
Name authority | Linnaeus: Sp. Pl. 1: 457. (1753) — (as lathyrus) | Jacquin: Enum. Syst. Pl., 22. (1760) |
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