Euphorbia perennans |
Euphorbia oblongata |
|
---|---|---|
perennial sandmat, Terlingua spurge |
Balkan spurge, egg-leaf spurge, oblong spurge |
|
Habit | Herbs, perennial, with strongly thickened, woody rootstock. | Herbs, perennial, with woody taproot. |
Stems | erect, 7–45 cm, glabrous. |
erect, unbranched or densely branching, 80 cm, often densely villous (especially young stems and pleiochasial branches). |
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. |
petiole absent; blade oblong to narrowly obovate or lanceolate, 15–70 × 6–25 mm, base rounded or truncate, margins finely serrulate, apex obtuse, mucronulate, surfaces glabrous; venation inconspicuously pinnate, midvein prominent. |
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. |
cupulate to slightly turbinate, 1.5–2.5 × 1.3–1.5 mm, glabrous; glands 2–3, elliptic, 0.6–0.8 × 0.8–1.2 mm; horns absent. |
Staminate flowers | 35–45. |
15–40. |
Pistillate flowers | ovary glabrous; styles 0.7–0.9 mm, 2-fid nearly entire length. |
ovary glabrous; styles 1.5–2 mm, 2-fid. |
Capsules | subglobose to broadly ovoid, 2.8–3.3 × 2.8–3.4 mm, glabrous; columella 2.2–2.7 mm. |
globose, 3–4.5 × 3–4.5 mm, slightly 3-lobed; cocci rounded, verrucose-tuberculate, glabrous; columella 2.5–3.3 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. |
brown, ovoid, 2.4–2.6 × 1.3–2 mm, smooth, caruncle reniform, 0.2–0.3 × 0.8–0.9 mm. |
Cyathia | solitary at distal nodes or at nodes of short, axillary branches; peduncle 1.8–3 mm. |
peduncle 1–5 mm. |
Cyathial | arrangement: terminal pleiochasial branches 3–5, each 2–3 times 2–4-branched; pleiochasial bracts ovate, similar in size to distal leaves; dichasial bracts distinct, ovate to suborbiculate, base truncate or rounded, margins entire or finely denticulate, apex obtuse, sometimes mucronulate; axillary cymose branches 0–4. |
|
Euphorbia perennans |
Euphorbia oblongata |
|
Phenology | Flowering and fruiting spring–fall. | Flowering and fruiting spring–fall. |
Habitat | Desert scrub, on cretaceous and gypseous clay, limestone hills and flats. | Waste areas, disturbed sites, roadsides, fields, pastures. |
Elevation | 900–1200 m. (3000–3900 ft.) | 30–900 m. (100–3000 ft.) |
Distribution |
TX; Mexico (Chihuahua) |
CA; OR; WA; s Europe [Introduced in North America]
|
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 oblongata is listed as a noxious weed by the states of California, Oregon, and Washington. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 282. | FNA vol. 12, p. 305. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Chamaesyce perennans | Tithymalus oblongatus |
Name authority | (Shinners) Warnock & M. C. Johnston: SouthW. Naturalist 5: 170. (1960) | Grisebach: Spic. Fl. Rumel. 1: 136. (1843) |
Web links |
|