Euphorbia polycarpa |
Euphorbia parryi |
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smallseed sandmat |
dune spurge, Parry's sandmat, Parry's spurge |
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Habit | Herbs, annual, with taproot. | |
Stems | usually prostrate, rarely ascending-erect, 5–70(–85) cm, glabrous. |
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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. |
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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. |
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Staminate flowers | 40–55. |
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Pistillate flowers | ovary glabrous; styles 0.5–0.7 mm, 2-fid nearly entire length. |
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Capsules | ovoid-globose, 2–2.3 × 1.5–2.5 mm, glabrous; columella 1.4–2 mm. |
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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. |
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Euphorbia | polycarpa is a highly variable species distributed throughout the Baja California peninsula, eastern Sonora, and the arid southwestern United States from southwestern Arizona to southern Nevada and central California. |
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l | . |
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c | . |
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Wheeler | (1941) divided the species into seven varieties, the majority of which occur in Baja California Sur. |
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He | reported two of these for the United States: var. hirtella and var. polycarpa. |
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Variety | hirtella, as the name suggests, was applied to hairy plants. |
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However | , it is here treated as a synonym of var. polycarpa, because variation in pubescence shows no geographic segregation and ranges along a continuum from glabrous or sparsely to densely hairy, and because glabrous and hairy branches can occur on the same individual. |
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Cyathia | solitary or in small clusters on short axillary branches at distal nodes; peduncle 1–5 mm. |
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Euphorbia polycarpa |
Euphorbia parryi |
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Phenology | Flowering and fruiting spring–fall. | |
Habitat | Sand dunes, other sandy habitats. | |
Elevation | 200–2200 m. (700–7200 ft.) | |
Distribution |
AZ; CA; NV; nw Mexico
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AZ; CA; CO; NM; NV; TX; UT; Mexico (Chihuahua)
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Discussion | Varieties 5 (1 in the flora). Some of the varieties occurring in Mexico are highly divergent and appear to be sufficiently distinct to merit recognition as species. However, within the flora area, Euphorbia polycarpa is relatively uniform, and the only noteworthy variation involves the size of the involucral gland appendages. In the portion of the California Floristic Province occupied by E. polycarpa (Los Angeles, Orange, western Riverside, western San Diego, and Ventura counties) the appendages are conspicuously larger than those of plants throughout the remainder of its range in the southwestern United States (0.4–1.2 versus 0.1–0.3 mm). Large-appendaged plants are also common in Baja California and correspond well with the type collection. The taxonomic significance of this variation is not clear at this time, and the small-appendaged plants may merit segregation as an infraspecific taxon. However, no formal changes are proposed, awaiting a comprehensive review of the species throughout its range. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 12, p. 283. | FNA vol. 12, p. 281. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Subordinate taxa | ||
Synonyms | Chamaesyce polycarpa | Chamaesyce longeramosa, C. parryi, E. longeramosa |
Name authority | Bentham: Bot. Voy. Sulphur, 50. (1844) | Engelmann: Amer. Naturalist 9: 350. (1875) |
Web links |