Difference between revisions of "Euphorbia perennans"

(Shinners) Warnock & M. C. Johnston

SouthW. Naturalist 5: 170. 1960.

Common names: Terlingua spurge perennial sandmat
Basionym: Chamaesyce perennans Shinners Field & Lab. 24: 38. 1956
Treatment appears in FNA Volume 12. Treatment on page 282. Mentioned on page 257, 270.
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Revision as of 18:19, 24 September 2019

Herbs, perennial, with strongly thickened, woody rootstock. Stems erect, 7–45 cm, glabrous. Leaves opposite; stipules distinct, linear-filiform in (1–)2(–3) segments, 0.3–0.4 mm, glabrous; petiole 0.8–2 mm, glabrous; blade ovate or orbiculate-deltate to reniform-deltate, 5–17 × 4–16 mm midstem leaves largest, base symmetric, cuneate, rounded to cordate, margins entire, apex acute to rounded, surfaces glabrous, often glaucous; 3-veined from base, only midvein conspicuous. Cyathia solitary at distal nodes or at nodes of short, axillary branches; peduncle 1.8–3 mm. Involucre broadly-campanulate to hemispheric, 1.7–2.2 × 1.5–2.7 mm, glabrous; glands 4, green to yellow-green, elliptic to oblong, folded longitudinally, 0.3–0.5 × 0.7–1.4 mm; appendages absent. Staminate flowers 35–45. Pistillate flowers: ovary glabrous; styles 0.7–0.9 mm, 2-fid nearly entire length. Capsules subglobose to broadly ovoid, 2.8–3.3 × 2.8–3.4 mm, glabrous; columella 2.2–2.7 mm. Seeds white to light brown, ovoid, 3–4-angled in cross section, 2–2.4 × 1–1.2 mm, smooth to faintly transverse-wrinkled.


Phenology: Flowering and fruiting spring–fall.
Habitat: Desert scrub, on cretaceous and gypseous clay, limestone hills and flats.
Elevation: 900–1200 m.

Discussion

Euphorbia perennans is a distinctive species with an erect habit and relatively large, firm, deltate midstem leaves. Phylogenetic data place E. perennans in a clade of primarily Chihuahuan Desert annual and perennial species (for example, E. chaetocalyx, E. fendleri, E. golondrina, E. simulans, E. spurca, and E. theriaca; Y. Yang and P. E. Berry 2011).

Euphorbia perennans is known in the flora area only from Brewster County.

Selected References

None.

Lower Taxa

None.
... more about "Euphorbia perennans"
Victor W. Steinmann +, Jeffery J. Morawetz +, Paul E. Berry +, Jess A. Peirson +  and Ya Yang +
(Shinners) Warnock & M. C. Johnston +
Chamaesyce perennans +
Terlingua spurge +  and perennial sandmat +
Tex. +  and Mexico (Chihuahua). +
900–1200 m. +
Desert scrub, on cretaceous and gypseous clay, limestone hills and flats. +
Flowering and fruiting spring–fall. +
SouthW. Naturalist +
Chamaesyce +
Euphorbia perennans +
Euphorbia sect. Anisophyllum +
species +