Euphorbia parryi |
Euphorbia yaquiana |
|
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dune spurge, Parry's sandmat, Parry's spurge |
hairy Mojave spurge |
|
Habit | Herbs, annual, with taproot. | Herbs, perennial, with thick rootstock. |
Stems | usually prostrate, rarely ascending-erect, 5–70(–85) cm, glabrous. |
slender, erect or ascending, sometimes sinuous, densely branched near base, 10–50 cm, moderately to densely puberulent to lanulose. |
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 0–1 mm; blade usually lanceolate or elliptic-lanceolate, sometimes slightly oblanceolate, 8–30 × 6–14 mm, base usually acute, occasionally short-attenuate, rarely obtuse, margins entire, apex usually acute, occasionally obtuse, acuminate, or cuspidate, surfaces sparsely to moderately puberulent to lanulose; venation pinnate, sometimes obscure, 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. |
campanulate to broadly turbinate, 2.2–3 × 2–2.5 mm, puberulent to lanulose; glands 4, semicircular, trapezoidal, or elliptic-truncate, 0.8–1.5 × 1–2.2 mm, margins strongly crenate or dentate; horns usually absent, if present then straight, 0.1–0.2 mm, generally equaling teeth on gland margin. |
Staminate flowers | 40–55. |
12–20. |
Pistillate flowers | ovary glabrous; styles 0.5–0.7 mm, 2-fid nearly entire length. |
ovary usually puberulent, occasionally lanulose; styles 1–1.2 mm, 2-fid. |
Capsules | ovoid-globose, 2–2.3 × 1.5–2.5 mm, glabrous; columella 1.4–2 mm. |
oblong-ovoid, 3.5–4 × 3–4 mm, 3-lobed; cocci rounded, smooth, usually puberulent, occasionally lanulose; columella 2.5–3 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 whitish, oblong cylindric, 2–3 × 1.5–1.8 mm, irregularly shallowly pitted to almost smooth; caruncle conic, 0.6 × 0.6 mm. |
Cyathia | solitary or in small clusters on short axillary branches at distal nodes; peduncle 1–5 mm. |
peduncle 0.3–0.8 mm. |
Cyathial | arrangement: terminal pleiochasial branches 3–5, each 1–2 times 2-branched; pleiochasial bracts broadly ovate to subcordate, usually similar in size to, occasionally wider than, distal leaves; dichasial bracts distinct, broadly ovate to almost reniform, base obtuse, margins entire, apex obtuse, acuminate to cuspidate; axillary cymose branches 0–5. |
|
Euphorbia parryi |
Euphorbia yaquiana |
|
Phenology | Flowering and fruiting spring–fall. | Flowering and fruiting spring–summer. |
Habitat | Sand dunes, other sandy habitats. | Ponderosa pine forests, oak-pine mixed forests, dry stream banks and beds, open scrub areas, roadsides. |
Elevation | 200–2200 m. (700–7200 ft.) | 1000–2200 m. (3300–7200 ft.) |
Distribution |
AZ; CA; CO; NM; NV; TX; UT; Mexico (Chihuahua)
|
AZ |
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 yaquiana is endemic to Pima and Graham counties in southern Arizona and is known only from the Santa Catalina and Pinaleño mountains. Records of E. yaquiana from southwestern Colorado (as E. incisa var. mollis) likely represent misidentifications of E. brachycera; therefore, those disjunct occurrences have been excluded here from the distribution of E. yaquiana. Euphorbia yaquiana has often been treated as a synonym of E. schizoloba var. mollis, but molecular phylogenetic data show that it is more closely related to E. brachycera and E. chamaesula (J. A. Peirson et al. 2014). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 281. | FNA vol. 12, p. 313. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > subg. Esula |
Sibling taxa | ||
Synonyms | Chamaesyce longeramosa, C. parryi, E. longeramosa | E. schizoloba var. mollis, E. incisa var. mollis |
Name authority | Engelmann: Amer. Naturalist 9: 350. (1875) | Tidestrom: Proc. Biol. Soc. Wash. 48: 41. (1935) |
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