Euphorbia ipecacuanhae |
Euphorbia geyeri |
|||||
---|---|---|---|---|---|---|
American ipecac, Carolina ipecac, ipecac spurge |
Geyer's sandmat, Geyer's spurge |
|||||
Habit | Herbs, perennial, with deep, stout rootstock. | Herbs, annual, with taproot. | ||||
Stems | decumbent or slightly ascending, branched, often densely clumped, previous year's dead stems not persistent, 17–27 cm, usually glabrous, rarely sparsely villous. |
prostrate or slightly ascending, loosely mat-forming, 4–25(–45) cm, glabrous. |
||||
Leaves | alternate; stipules 0.1–0.2 mm; petiole (0–)1–2 mm, glabrous; blade usually linear, obovate, or oblanceolate to orbiculate, rarely filiform, proximal greatly reduced, scalelike, 15–70 × 1.5–13 mm gradually smaller proximally, base cuneate, margins entire, apex rounded, broadly acute, or emarginate, surfaces glabrous; venation occasionally obscure on smaller leaves, midvein conspicuous. |
opposite; stipules usually distinct, occasionally connate basally on lower side, usually deeply parted into 3 or more filiform segments, 0.7–1.5 mm, glabrous; petiole 1–2 mm, glabrous; blade oblong to oblong-obovate or oblong-elliptic, 4–12 × 2–6 mm, base slightly asymmetric, angled or rounded, with one side usually expanded into small, rounded auricle, margins entire, apex usually truncate, occasionally emarginate, abaxial surface pale grayish green, both surfaces glabrous; only midvein conspicuous or venation obscurely pinnate (larger leaves). |
||||
Involucre | yellow or yellow-green, hemispheric, 1–1.2 × 2–2.4 mm, glabrous; glands 5, yellow or yellow-green, obovate or elliptic, 0.7–0.8 × 1–1.2 mm; appendages white or green, often forming narrow rim around distal margin of gland, 0–0.2 mm, entire. |
broadly campanulate, 1–1.5 × 0.7–0.9 mm, glabrous; glands 4, green to reddish, elliptic-oblong to nearly circular, slightly cupped to folded, 0.2–0.4 × 0.2–0.6 mm; appendages rudimentary to absent or white to reddish-tinged, usually rounded, sometimes pointed, (0–)0.5–1 × (0–)0.1–1.2 mm, distal margin entire or slightly toothed. |
||||
Staminate flowers | 10–20. |
5–20. |
||||
Pistillate flowers | ovary glabrous; styles 0.4–0.8 mm, 2-fid at apex. |
ovary glabrous; styles 0.2–0.6 mm, 2-fid nearly 1/2 length. |
||||
Capsules | globose, 2.3–3.4 × 3.5–4.2 mm, glabrous; columella 3–3.1 mm. |
globose-ovoid, 1.5–2 × 1.5–3 mm, glabrous; columella 1.5–1.9 mm. |
||||
Seeds | white or brown, ovoid, 2.3–2.5 × 1.5 mm, angular, with 5 longitudinal ridges, shallowly and irregularly pitted; caruncle absent. |
ashy white, ovoid, terete to bluntly subangled in cross section, 1.1–1.7 × 0.9–1.2 mm, smooth, with smooth brown line from top to bottom on adaxial side. |
||||
Cyathia | usually in terminal dichasia, sometimes pleiochasia; peduncle 10–50(–70) mm, glabrous. |
solitary or in small, cymose clusters at distal nodes; peduncle 1–2 mm. |
||||
Euphorbia ipecacuanhae |
Euphorbia geyeri |
|||||
Phenology | Flowering and fruiting early spring–early summer. | |||||
Habitat | Pine and pine-oak savannas, pine-oak sand hills, turkey oak scrub, open sand habitats. | |||||
Elevation | 0–150 m. (0–500 ft.) | |||||
Distribution |
CT; DC; DE; GA; MD; NC; NJ; NY; PA; SC; VA
|
CO; IA; IL; IN; KS; LA; MI; MN; MO; MS; MT; ND; NE; NM; OK; SD; TX; UT; WI; WY; MB; n Mexico
|
||||
Discussion | The vegetative stems of Euphorbia ipecacuanhae are often quite short in proportion to the dichasial or pleiochasial branches, thus superficially plants often appear to have mostly opposite leaves. However, careful examination of the base of the plant will reveal alternate leaves. The leaves are extremely variable in both shape and coloration, and the variation can be pronounced within a population or even on a single plant. M. J. Huft (1979) did not recognize infraspecific taxa within E. ipecacuanhae, and his treatment is followed here. This species is found on the Atlantic coastal plain. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Varieties 2 (2 in the flora). The two varieties of Euphorbia geyeri have been distinguished in large part by the presence of conspicuous involucral gland appendages in var. geyeri and the lack of appendages in var. wheeleriana. The two varieties are recognized here, but the variation in the size and presence of involucral gland appendages in the closely related E. bombensis suggests that this might be a somewhat variable character in this group of species. Euphorbia geyeri is widespread throughout the central United States in sandy soils. Populations at the eastern edge of the range are often considered adventive (for example, sandy soils along railroad grades in Michigan). Euphorbia geyeri resembles E. glyptosperma (both being entirely glabrous), but that species has serrulate leaves (near the apex) and strongly angled, transverse-ridged seeds whereas E. geyeri has entire leaves and smooth, rounded seeds. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
||||
Key |
|
|||||
Source | FNA vol. 12, p. 247. | FNA vol. 12, p. 268. | ||||
Parent taxa | Euphorbiaceae > Euphorbia > sect. Alectoroctonum | Euphorbiaceae > Euphorbia > sect. Anisophyllum | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | E. arundelana, Tithymalopsis ipecacuanhae | Chamaesyce geyeri | ||||
Name authority | Linnaeus: Sp. Pl. 1: 455. (1753) | Engelmann: Boston J. Nat. Hist. 5: 260. (1845) | ||||
Web links |