232 



American Midland Naturalist Monograph No. 4 



or without short nodding branches; occurs on rocky banks and in mountain 

 canyons in the Southwest. 



Occurrence. — GRAND CANYON, rare on the North Rim; 

 Point; Lauzon Ranch. 



Point Sublime; Grama 



Fig. 141. Big sagebrush (Artemhia 

 tridentala) . 



3. Big Sagebrush (Artemisia 

 tridentata Nutt.), fig. 141. — Shrub 

 1 to 12 feet high, with a definite 

 trunk or with several trunk-Uke 

 branches; herbage silvery -gray or 

 whitish with dense but thin fine 

 hairs; bark dark brown or nearly 

 black, shreddy; leaves narrowly 

 wedge-shaped, 2/3 to 2 inches long, 

 usually 3 -toothed (or sometimes 4- 

 or 5-toothed) at the tip; flowers 

 mostly 4 to 6 (or 9), borne in small 

 heads surrounded at the base by a 

 close cup of finely hairy overlapping 

 scales; heads yellowish or brownish, 

 borne in rather loose clusters 1 to 4 

 inches across. 



This is one of the most common 

 and familiar of western shrubs and 

 becomes the largest of the western 

 sagebrushes. It is a very variable 

 species with numerous varieties, many 

 of which are often recognized as dis- 

 tinct species. Big sagebrush occurs 

 commonly on dry plains but may 

 also be found in dry open forests, 

 particularly in the Southwest where 

 it grows luxuriantly. The species is 

 generally known as an indicator of 

 deep soils largely free from alkali. 

 The plant furnishes an important 

 fuel in the regions where it is com- 

 mon. The stringy bark is easily ig- 

 nited and the burning wood pro- 

 duces an intense heat. The fruits 

 were pounded by the California 

 Indians to make pinole, a kind of 

 a flour. 



Field Guide to the Varieties 

 F^lants 1 to 12 feet high; leaves 2/3 to 2 inches long, mostly 3-toothed at tip; 

 flower clusters loosely branched, 1 to 4 inches broad; heads mostly 4- to 6- 



flowered; widespread 3. A. iridentata. 



Plants 1/3 to 4 feet high; flower clusters often spike-like, about 1/5 to 1 inch broad. 

 Leaves, or some of them 3-toothed at tip (not cleft). 



