Euphorbia parryi |
Euphorbia chamaesula |
|
---|---|---|
dune spurge, Parry's sandmat, Parry's spurge |
mountain spurge |
|
Habit | Herbs, annual, with taproot. | Herbs, perennial, with thick rootstock. |
Stems | usually prostrate, rarely ascending-erect, 5–70(–85) cm, glabrous. |
erect, branched, 40–90 cm, glabrous. |
Leaves | opposite; stipules distinct, linear-subulate, usually lacerate and divided into 2 or more slender segments, rarely entire, 0.6–1.4 mm, glabrous; petiole 1–2.5 mm, glabrous; blade linear to narrowly oblong, (5–)10–25(–30) × 2–5 mm, base usually symmetric, sometimes slightly asymmetric, attenuate, margins entire, occasionally ± revolute, apex acute to obtuse, mucronulate, surfaces glabrous; only midvein conspicuous. |
petiole 0.5–1 mm; blade elliptic to oblong, 8–20(–40) × 3–6 mm, base truncate, rounded, or attenuate, margins entire, apex obtuse or acute, sometimes slightly mucronate, surfaces glabrous; venation inconspicuous, only midvein prominent. |
Involucre | broadly cupuliform-campanulate, 1.2–1.7 × 1.4–1.8 mm, glabrous; glands 4, reddish pink to greenish yellow, deeply concave, elliptic to oblong, 0.2–0.3 × 0.3–0.5 mm; appendages white, elliptic to oblong, usually forming narrow margin around gland, sometimes rudimentary, 0.2–0.6 × 0.3–0.7(–1.1) mm, distal margin entire. |
turbinate or campanulate, 1.5–2.5 × 1.1–1.9 mm, glabrous; glands 4, crescent-shaped to semicircular, 0.5–0.8 × 1–1.8 mm; horns usually convergent, 0.2–0.8 mm. |
Staminate flowers | 40–55. |
8–12. |
Pistillate flowers | ovary glabrous; styles 0.5–0.7 mm, 2-fid nearly entire length. |
ovary glabrous; styles 1–1.8 mm, 2-fid. |
Capsules | ovoid-globose, 2–2.3 × 1.5–2.5 mm, glabrous; columella 1.4–2 mm. |
depressed-ovoid, 4.3–5 × 5–6 mm, 3-lobed; cocci rounded, smooth, glabrous; columella 3.5–4 mm. |
Seeds | mottled brown and white because of irregularly loose and tight outer covering, broadly ovoid, rounded-angular in cross section, 1.4–1.8 × 0.8–1 mm, smooth or only inconspicuously roughened. |
gray to dark brown, ovoid-oblong, truncate at both ends, 2.6–3.4 × 2–2.6 mm, shallowly pitted to almost smooth; caruncle conic, 1 × 0.8 mm. |
Cyathia | solitary or in small clusters on short axillary branches at distal nodes; peduncle 1–5 mm. |
peduncle 1–3 mm. |
Cyathial | arrangement: terminal pleiochasial branches 3–5(–6), each 3–4 times 2-branched; pleiochasial bracts ovate-lanceolate to slightly subpandurate, similar in size or wider than distal leaves; dichasial bracts distinct, lanceolate to broadly ovate, base usually truncate to rounded or subcordate, sometimes attenuate, margins entire or slightly crenulate, apex usually obtuse to acute, occasionally acuminate; axillary cymose branches 2–8. |
|
2n | = 26. |
|
Euphorbia parryi |
Euphorbia chamaesula |
|
Phenology | Flowering and fruiting spring–fall. | Flowering and fruiting spring–summer. |
Habitat | Sand dunes, other sandy habitats. | Clearings in ponderosa pine forests, montane roadsides, dry streambeds, creek banks, sandy and gravelly soils. |
Elevation | 200–2200 m. (700–7200 ft.) | 1700–2700 m. (5600–8900 ft.) |
Distribution |
AZ; CA; CO; NM; NV; TX; UT; Mexico (Chihuahua)
|
AZ; NM; Mexico (Chihuahua, Sonora)
|
Discussion | Euphorbia parryi is similar to E. missurica, differing only by the generally narrow involucral gland appendages and prostrate habit in E. parryi as opposed to the conspicuous involucral gland appendages and ascending-erect habit in E. missurica. Euphorbia parryi has sometimes been considered the western race of E. missurica (D. S. Correll and M. C. Johnston 1970). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Euphorbia chamaesula is easily distinguished from other perennial members of subg. Esula in western North America by its larger capsules and the vegetative shoots (without cyathia) that arise from the distal nodes of the stem proximal to the pleiochasia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 281. | FNA vol. 12, p. 300. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > subg. Esula |
Sibling taxa | ||
Synonyms | Chamaesyce longeramosa, C. parryi, E. longeramosa | Tithymalus chamaesula |
Name authority | Engelmann: Amer. Naturalist 9: 350. (1875) | Boissier: Cent. Euphorb., 38. (1860) |
Web links |