Euphorbia perennans |
Euphorbia nutans |
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perennial sandmat, Terlingua spurge |
eyebane, eyebane sandmat, eyebane spurge, nodding or upright spotted spurge, nodding spurge |
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Habit | Herbs, perennial, with strongly thickened, woody rootstock. | Herbs, annual, with taproot. |
Stems | erect, 7–45 cm, glabrous. |
usually ascending, occasionally erect, often arched at tips, 20–80 cm, sparsely to moderately pilose to villous or with short, incurved hairs, hairs often concentrated at nodes and distally, occasionally in 2 bands along opposite sides of stem. |
Leaves | opposite; stipules distinct, linear-filiform in (1–)2(–3) segments, 0.3–0.4 mm, glabrous; petiole 0.8–2 mm, glabrous; blade ovate or orbiculate-deltate to reniform-deltate, 5–17 × 4–16 mm midstem leaves largest, base symmetric, cuneate, rounded to cordate, margins entire, apex acute to rounded, surfaces glabrous, often glaucous; 3-veined from base, only midvein conspicuous. |
opposite; stipules usually distinct, sometimes connate basally on one side of stem, small scales, irregularly toothed, fringed, or divided, 1–1.5 mm, sparsely to moderately villous distally; petiole 0.3–1.6 mm, moderately pilose to villous; blade oblong to oblong-lanceolate, 8–40 × 3–12 mm, base asymmetric, one side usually angled or rounded, other side ± truncate to cordate-auriculate, margins serrulate, apex angled with blunt tip, abaxial surface pale green or faintly to strongly reddish tinged, adaxial surface usually reddish-mottled or with conspicuous reddish spot, both surfaces usually sparsely to moderately pilose, especially toward base, sometimes glabrous; 3–5-veined from base, pinnate distally, veins faint. |
Involucre | broadly-campanulate to hemispheric, 1.7–2.2 × 1.5–2.7 mm, glabrous; glands 4, green to yellow-green, elliptic to oblong, folded longitudinally, 0.3–0.5 × 0.7–1.4 mm; appendages absent. |
narrowly obconic, 0.5–1 × 0.3–0.7 mm, glabrous; glands 4, usually green, sometimes reddish purple, oblong to nearly circular, 0.2–0.4 × 0.3–0.5 mm; appendages white or pinkish, ovate to broadly elliptic, 0.2–1 × 0.2–1.5 mm, distal margin entire. |
Staminate flowers | 35–45. |
5–28. |
Pistillate flowers | ovary glabrous; styles 0.7–0.9 mm, 2-fid nearly entire length. |
ovary glabrous; styles 0.6–2.5 mm, 2-fid 1/2 length. |
Capsules | subglobose to broadly ovoid, 2.8–3.3 × 2.8–3.4 mm, glabrous; columella 2.2–2.7 mm. |
ovoid, 1.6–2.3 × 1.5–2.4 mm, glabrous; columella 1.4–1.6 mm. |
Seeds | white to light brown, ovoid, 3–4-angled in cross section, 2–2.4 × 1–1.2 mm, smooth to faintly transverse-wrinkled. |
dark brown, sometimes with thin, white coating (often more persistent along angles than faces), elliptic-ovoid to ovoid, rounded-angular in cross section, 1–1.6 × 0.5–0.8 mm, surface finely and irregularly wrinkled, sometimes faintly so, or with indistinct, shallow, rounded cross ridges. |
Cyathia | solitary at distal nodes or at nodes of short, axillary branches; peduncle 1.8–3 mm. |
solitary at distal nodes or in small, cymose clusters at branch tips; peduncle 0.5–2.5 mm. |
2n | = 12, 14, 22. |
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Euphorbia perennans |
Euphorbia nutans |
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Phenology | Flowering and fruiting spring–fall. | Flowering and fruiting spring–early fall. |
Habitat | Desert scrub, on cretaceous and gypseous clay, limestone hills and flats. | Stream banks, pond edges, disturbed portions of upland prairies, mesic to dry upland forest openings, pastures, fallow fields, railroads, roadsides, gardens, disturbed areas. |
Elevation | 900–1200 m. (3000–3900 ft.) | 0–1600 m. (0–5200 ft.) |
Distribution |
TX; Mexico (Chihuahua) |
AL; AR; CA; CT; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; MI; MN; MO; MS; NC; ND; NE; NH; NJ; NM; NY; OH; OK; PA; RI; SC; SD; TN; TX; VA; VT; WI; WV; WY; ON; QC; Mexico; Central America; South America; West Indies [Introduced in Eurasia]
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Discussion | Euphorbia perennans is a distinctive species with an erect habit and relatively large, firm, deltate midstem leaves. Phylogenetic data place E. perennans in a clade of primarily Chihuahuan Desert annual and perennial species (for example, E. chaetocalyx, E. fendleri, E. golondrina, E. simulans, E. spurca, and E. theriaca; Y. Yang and P. E. Berry 2011). Euphorbia perennans is known in the flora area only from Brewster County. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Euphorbia nutans is probably native to at least central and eastern North America, but given its strongly weedy tendencies, it is difficult to know where it may be adventive in parts of the flora area. It is certainly introduced where it occurs in the Old World and probably in South America as well. D. G. Burch (1966) discussed the problems of assigning names to the four main entities in this nomenclatural complex (E. hypericifolia, E. hyssopifolia, E. lasiocarpa, and E. nutans) and determined that the oldest valid name for the relatively robust, temperate North American plants with ascending stems is E. nutans. See the treatment of 56. E. maculata for a discussion of the misapplication of that name to E. nutans. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 282. | FNA vol. 12, p. 278. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Chamaesyce perennans | Chamaesyce lansingii, C. nutans, E. lansingii, E. preslii |
Name authority | (Shinners) Warnock & M. C. Johnston: SouthW. Naturalist 5: 170. (1960) | Lagasca: Gen. Sp. Pl., 17. (1816) |
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