Euphorbia villifera |
Euphorbia helleri |
|
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hairy spurge |
Heller's spurge |
|
Habit | Herbs, annual or perennial, with slender taproot or thickened, woody rootstock. | Herbs, annual, with taproot. |
Stems | usually erect to ascending, rarely prostrate to decumbent, 10–30 cm, papillate, usually villous, sometimes glabrous. |
ascending, branched proximally, 15–30 cm, glabrous. |
Leaves | opposite; stipules distinct, filiform, usually undivided, rarely divided into 2–3 segments), 0.3–0.7 mm, glabrous, papillate; petiole 0.6–1.8 mm, usually villous, rarely glabrous; blade ovate, 3–12 × 2–10 mm, base asymmetric, rounded to slightly cordate, margins entire or serrulate, apex acute to obtuse, surfaces usually villous, rarely glabrous; only midvein conspicuous. |
petiole usually 1–3 mm, absent distally; blade spatulate, 6–15 × 3–5 mm, base broadly attenuate, margins entire, apex usually obtuse to rounded, sometimes retuse, surfaces glabrous; venation pinnate, midvein prominent. |
Involucre | campanulate, 0.7–0.9 × 0.6–1 mm, glabrous or pilose; glands 4, pink, oval, oblong, or trapezoidal, 0.1–0.2 × 0.2 mm; appendages white to pink, flabellate, oblong, ovate, or nearly rectangular, 0.2–0.4 × 0.2–0.6 mm, distal margin entire. |
campanulate, 0.9–1.2 × 0.7–1 mm, glabrous; glands 4, elliptic, 0.1–0.2 × 0.3–0.4 mm; horns slightly divergent, 0.1–0.2 mm. |
Staminate flowers | 10–25. |
8–10. |
Pistillate flowers | ovary glabrous; styles 0.3–0.5 mm, 2-fid 1/2 to nearly entire length. |
ovary glabrous; styles 0.4–0.5 mm, 2-fid. |
Capsules | oblate-deltoid, cocci often elongated and terminating in an empty portion, 1.5–2 × 2.1–3.1 mm, glabrous; columella 0.9–1.5 mm. |
depressed-globose, 2.1–2.5 × 2.5–3 mm, 3-lobed; cocci flattened, smooth, glabrous; columella 1.2–1.7 mm. |
Seeds | gray-brown to red-brown, ovoid-oblong, weakly 4-angled in cross section, 1–1.4 × 0.6–0.8 mm, smooth, faintly rugose, or with inconspicuous transverse ridges. |
white to light gray, ovoid, 1.4–1.6 × 1–1.2 mm, smooth; caruncle 2-lobed, thin, 0.4 × 0.7 mm. |
Cyathia | solitary at distal nodes; peduncles 0–1.8 mm. |
peduncle 0.2–0.4 mm. |
Cyathial | arrangement: terminal pleiochasial branches 3, each 1–5 times 2-branched; pleiochasial bracts oblong, similar in size to distal leaves; dichasial bracts distinct, orbiculate-ovate to nearly reniform, subpandurate, base broadly cuneate to truncate, margins entire, apex obtuse, mucronate; axillary cymose branches 0–5. |
|
Euphorbia villifera |
Euphorbia helleri |
|
Phenology | Flowering and fruiting early spring–early winter. | Flowering and fruiting late winter–spring. |
Habitat | Riparian forests with walnuts and sycamores, juniper woodlands, pine-oak woodlands, mostly on limestone substrates. | Forests, stream banks, roadsides, shaded areas with sandy, calcareous soils. |
Elevation | 100–1400 m. (300–4600 ft.) | 0–50 m. (0–200 ft.) |
Distribution |
TX; Mexico; Central America |
LA; TX; Mexico (Nuevo León) |
Discussion | Although Euphorbia villifera has been reported from New Mexico (W. C. Martin and C. R. Hutchins 1980), no vouchers to verify its presence there were located. In Texas, E. villifera is known from the Edwards Plateau westward into the trans-Pecos region. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
The smooth, white to light gray seeds of Euphorbia helleri easily distinguish it from other annual members of subg. Esula in North America. Collections of E. helleri have been made near Brownsville, Texas, and thus it is possible that the species occurs in northern Tamaulipas, Mexico. The Louisiana record (Webster Parish) likely represents introduced plants. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 293. | FNA vol. 12, p. 303. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > subg. Esula |
Sibling taxa | ||
Synonyms | Chamaesyce stanfieldii, C. villifera, E. stanfieldii, E. villifera var. nuda | Tithymalus helleri |
Name authority | Scheele: Linnaea 22: 153. (1849) | Millspaugh: Bot. Gaz. 26: 268, fig. [p. 270]. (1898) |
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