Euphorbia hyssopifolia |
Euphorbia dendroides |
|
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hyssopleaf sandmat |
tree spurge |
|
Habit | Herbs, annual, with taproot. | Shrubs, dendroid, with large rootstock. |
Stems | erect to ascending, 80 cm, sparsely to densely pilose or pilose-crinkled proximally, usually glabrous distally. |
erect, stout, densely branched, to 200 cm, glabrous, bark usually reddish and glossy toward tip of branches. |
Leaves | opposite; stipules usually connate, irregularly lacerate, 0.5–1 mm, usually glabrous, occasionally with few marginal hairs; petiole 1–2 mm, glabrous; blade lanceolate to oblong or falcate, 8–35 × 7–15 mm, base asymmetric, rounded, margins serrulate, apex broadly acute, abaxial surface glabrous or sparsely pilose toward base, adaxial surface glabrous; 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 | obconic, 0.9–1.1 × 0.7–0.9 mm, glabrous; glands 4(–5) (5th gland without appendage), yellow-green to maroon, elliptic to circular, 0.1–0.2 × 0.1–0.3 mm; appendages spreading, usually white or turning reddish with age, short reniform or semilunate, 0.1–0.3 × 0.2–0.6 mm, distal margin entire or slightly undulate to crenate. |
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 | 4–15. |
20–25. |
Pistillate flowers | ovary glabrous; styles 0.5–0.9 mm, 2-fid 1/2 length. |
ovary glabrous; styles 2.4–3 mm, 2-fid. |
Capsules | depressed-ovoid, 1.5–1.6 × 1.7–1.8 mm, glabrous; columella 1.5–2 mm. |
subglobose, 4–5.5 × 4–6.5 mm, deeply lobed; cocci laterally compressed, smooth, glabrous; columella 3–4 mm. |
Seeds | brown to grayish white, ovoid, slightly 4-angled in cross section, abaxial faces convex, adaxial faces slightly concave to slightly convex, 1–1.4 × 0.7–1.1 mm, with 2–3 prominent transverse ridges that do not interrupt adaxial keel, or coarsely and inconspicuously pitted-reticulate. |
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 | solitary or in small, cymose clusters occasionally with bractlike leaves at distal nodes or on congested, axillary branches; peduncle 0.5–2.5 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. |
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2n | = 12, 14. |
|
Euphorbia hyssopifolia |
Euphorbia dendroides |
|
Phenology | Flowering and fruiting late spring–early fall. | Flowering and fruiting fall–spring. |
Habitat | Disturbed areas, ditches, gardens. | Coastal plains and basins, hillsides. |
Elevation | 0–1500 m. (0–4900 ft.) | 0–500 m. (0–1600 ft.) |
Distribution |
AL; AZ; FL; GA; LA; MS; NM; SC; TX; UT; Mexico; Central America; South America; West Indies [Introduced in tropical Asia, Africa, Australia]
|
CA; Europe; n Africa [Introduced in North America] |
Discussion | Euphorbia hyssopifolia is native to the New World tropics and is probably also native to parts of the southern United States. However, at least some of the records from the flora area appear to be from adventive plants. (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. 272. | FNA vol. 12, p. 302. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > subg. Esula |
Sibling taxa | ||
Synonyms | Chamaesyce hyssopifolia, E. jonesii, E. stenomeres | Tithymalus dendroides |
Name authority | Linnaeus: Syst. Nat. ed. 10, 2: 1048. (1759) | Linnaeus: Sp. Pl. 1: 462. (1753) |
Web links |