Euphorbia hyssopifolia |
Euphorbia wrightii |
|
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hyssopleaf sandmat |
Wright's spurge |
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Habit | Herbs, annual, with taproot. | Herbs, perennial with cylindric rootstock or elongated tubers. |
Stems | erect to ascending, 80 cm, sparsely to densely pilose or pilose-crinkled proximally, usually glabrous distally. |
erect, branched, densely clumped, previous year’s dead stems often persistent, 20–50 cm, glabrous. |
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. |
alternate, persisting, spreading or ascending; stipules 0.1–0.3 mm; petiole absent; blade linear to linear-filiform, (17–)20–40 × 1–2.5 mm, base cuneate, slightly sheathing stem, margins entire, apex broadly acute to rounded, abaxial surface glabrous or sparsely villous, adaxial surface glabrous; venation obscure, only midvein conspicuous on wider leaves. |
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. |
campanulate, 1.5–2 × 1.8–2.5 mm, pilose; glands 5, green, broadly elliptic, 0.7–0.8 × 1 mm; appendages white to pink, orbiculate, 0.5–1 × 1.3–1.8 mm, coarsely erose. |
Staminate flowers | 4–15. |
20–25. |
Pistillate flowers | ovary glabrous; styles 0.5–0.9 mm, 2-fid 1/2 length. |
ovary strigose to tomentose; styles 1 mm, 2-fid at apex. |
Capsules | depressed-ovoid, 1.5–1.6 × 1.7–1.8 mm, glabrous; columella 1.5–2 mm. |
depressed-globose, 1 locule usually aborting, 2.5(–3) × 2.7–3.3(–5) mm, sparsely tomentose; columella 2.6–3 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. |
gray-green to gray-brown, globose-ovoid, 2.2–2.9 × 1.8–2 mm, shallowly and obscurely pitted; caruncle absent. |
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. |
usually in terminal dichasia, rarely pleiochasia; peduncle (3–)5–15 mm, all peduncles and cyathia persistent on plant, glabrous. |
2n | = 12, 14. |
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Euphorbia hyssopifolia |
Euphorbia wrightii |
|
Phenology | Flowering and fruiting late spring–early fall. | Flowering and fruiting spring–fall. |
Habitat | Disturbed areas, ditches, gardens. | Open grasslands and uplands, often on limestone outcrops. |
Elevation | 0–1500 m. (0–4900 ft.) | 500–1000 m. (1600–3300 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]
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TX; Mexico (Coahuila) |
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.) |
Within the flora area, Euphorbia wrightii is endemic to the western Edwards Plateau and adjacent rolling plains in western Texas. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 272. | FNA vol. 12, p. 251. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > sect. Alectoroctonum |
Sibling taxa | ||
Synonyms | Chamaesyce hyssopifolia, E. jonesii, E. stenomeres | |
Name authority | Linnaeus: Syst. Nat. ed. 10, 2: 1048. (1759) | Torrey & A. Gray: in War Department [U.S.], Pacif. Railr. Rep. 2(4): 174. (1857) |
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