Euphorbia cuphosperma |
Euphorbia melanadenia |
|
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hairy-fruit spurge |
red-gland spurge, squaw sandmat |
|
Habit | Herbs, annual, with taproot. | Herbs, perennial, with moderately to strongly thickened rootstock. |
Stems | erect, 13–20 cm, both pilose to villous and densely strigillose; branches ± straight. |
ascending to erect, 5–20 cm, sericeous to appressed-villous. |
Leaves | usually opposite, occasionally alternate at distal nodes; petiole 3–15 mm, pilose; blade narrowly to broadly elliptic, or lanceolate to ovate, 30–80 × 10–15 mm, base cuneate to rounded, margins coarsely crenate-dentate, strigose, revolute to nearly flat, apex broadly acute to acuminate, or obtuse, abaxial surface pilose, adaxial surface sparsely strigose-hirsute; venation pinnate, midvein prominent. |
opposite; stipules distinct (lower side) and connate (upper side), linear, 0.5–1 mm, densely pilose; petiole 0.8–1.5 mm, tomentose; blade ovate, 1.2–5 × 0.8–2.9 mm, base asymmetric, hemicordate, margins entire, apex rounded to acute, surfaces tomentose; venation inconspicuous. |
Involucre | campanulate to slightly cylindric, 2.3 × 1.2 mm, glabrous; involucral lobes divided into several linear, smooth lobes; gland 1, yellow-green, stipitate, clavate, 1–1.2 × 0.8–0.9 mm, opening bilabiate and oblong, glabrous; appendages absent. |
campanulate, 0.6–1.1 × 0.7–1 mm, tomentose; glands 4, deep red to purple, elliptic, 0.3–0.4 × 0.4–0.7 mm; appendages white or becoming pink with age, oblong to flabellate, 0.4–0.7(–1) × 0.7–1.2 mm, distal margin entire or erose. |
Staminate flowers | 3–5. |
45–80. |
Pistillate flowers | ovary pilose; styles 1.2 mm, 2-fid nearly entire length. |
ovary tomentose, styles 0.5–0.8 mm, 2-fid nearly entire length. |
Capsules | broadly ovoid, 2.2–3 × 1.9–2.7 mm, 3-lobed, pilose; columella 2–2.4 mm. |
ovoid, 1.4–1.8 × 1.4–1.7 mm, tomentose; columella 1.2–1.5 mm. |
Seeds | gray-brown to pale gray, pyramidally ovoid, angular in cross section, 2.3–2.6 × 2.4–2.6 mm, coarsely tuberculate, tubercles in 2 transverse rows; caruncle 0.2–0.4 mm. |
gray to tan, oblong, 4-angled in cross section, 1–1.2 × 0.4–0.6 mm, smooth to wrinkled or alveolate. |
Cyathial | arrangement: terminal pleiochasial branches usually 3, occasionally reduced to congested cyme, 1–2-branched; pleiochasial bracts 2–4, often whorled, wholly green or paler green at base, similar in shape and size to distal leaves or slightly narrower; dichasial bracts highly reduced. |
|
Cyathia | peduncle 0.5–0.8 mm. |
solitary at distal nodes; peduncle (0.6–)1.4–1.9 mm. |
2n | = 56. |
|
Euphorbia cuphosperma |
Euphorbia melanadenia |
|
Phenology | Flowering and fruiting summer–fall. | Flowering and fruiting year-round. |
Habitat | Open montane and canyon forests, pinyon-juniper forests, montane grasslands, stream beds, disturbed habitats. | Rocky slopes, river washes, dry to wet soils. |
Elevation | 800–2000 m. (2600–6600 ft.) | 400–1400 m. (1300–4600 ft.) |
Distribution |
AZ; NM; Mexico; Central America (Guatemala)
|
AZ; CA; Mexico (Baja California, Sonora)
|
Discussion | Euphorbia melanadenia is similar in appearance to E. cinerascens, but E. melanadenia has conspicuous involucral gland appendages whereas E. cinerascens has inconspicuous appendages or lacks them entirely. Euphorbia melanadenia occurs in Arizona and southern California, whereas E. cinerascens is found only in southern and western Texas. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 12, p. 319. | FNA vol. 12, p. 276. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Poinsettia | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | E. dentata var. cuphosperma, Poinsettia cuphosperma | Chamaesyce melanadenia |
Name authority | (Engelmann) Boissier: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 15(2): 73. (1862) | Torrey: in War Department [U.S.], Pacif. Railr. Rep. 4(5): 135. (1857) |
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