An Illustrated Guide to ARIZONA WEEDS

The University of Arizona Press



SPURGE FAMILY-Euphorbiaceae

POISONOUS PROPERTIES OF SPURGES-All spurges contain a white, sticky milky juice which may cause skin inflammation in some humans and livestock. Livestock rarely eat these green unpalatable plants, but they may eat them in hay. Cattle have been poisoned from feeding on such hay over a period of time. Losses in Arizona from this plant are probably common, but inflammation of the mouth area is more common.

WHITEMARGIN SPURGE, rattlesnake weed-Euphorbia albomarginata Torr. & Gray

DESCRIPTION-A prostrate hairless perennial, forming mats to 3 1/2 feet in diameter, reproducing by seeds and by frequent roots arising at the stem joints. The opposite, hairless leaves, 1/8 to 3/8 inch long, are smooth edged, often edged with white, and red blotched in the center. At the base of the leaf stalk, there is a thin whitish conspicuous scale formed by the 2 united stipules. The 3-lobed seedpods are hairless and each contains 3 seeds. The whitish 4-angled seeds are about 1/16 inch long, with almost smooth faces.

DISTRIBUTION-A common native weed throughout most of Arizona, and especially abundant in the southern part of the state. Found on dry barren disturbed soil along sidewalks, paths, waste places, roadsides, overgrazed or eroded areas around corrals, reservoirs, bedding places, washes, and mesas; 100 to 7,000 feet elevation; flowering February to November.

SAWTOOTH SPURGE-Euphorbia serrula Engelm.

DESCRIPTION-Sawtooth spurge also forms mats, but is annual. The stems have long spreading hairs, and the pale green leaves, either hairless or with a few long hairs, are sharply saw toothed along the edges. The 2 whitish stipules at the base of the leaf stalk are inconspicuous. A native weed with the same general distribution and habitat as whitemargin spurge, but mostly between 2,400 to 8,000 feet elevation; flowering from May to November.

LITTLELEAF SPURGE-Euphorbia micromera Boiss.

DESCRIPTION-A short hairy or hairless, matforming annual, but the leaves are very small, 1/16 to 1/4 (mostly 1/8 or less) inch long, and the edges are smooth The 2 whitish stipules at the base of the leaf stalk are triangular. A native weed found in the same type of places and the same general distribution of whitemargin spurge; flowering August to November.

Copyright (c) 1972 The Arizona Board of Regents

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