Bailey & Bailey: Woody Plants of National Parks 147 



oblong to nearly linear leaflets; flowers tiny, yellow, packed in dense oblong 

 clusters about 1 to 2 inches long; pods 2 to 6 inches long, pale brown, flat- 

 tened, mostly curved, strongly constricted between the seeds, ripening in the 

 Fall and often remaining on the branches for periods of from 6 to 8 months; 

 seeds nearly orbicular, somewhat 

 flattened like a disk, about 1/3 

 inch in diameter, dark, shiny 

 brown. 



This species is typically a des- 

 ert or semi-desert shrub charac- 

 teristic of the creosote belt of the 

 Southwest and frequently found in 

 association with honey mesquite. 

 The plants seem to thrive on poor 

 soil and, as is characteristic of all 

 members of the pea family, tend 

 to improve its fertility. The 

 common name, catclaw, is derived 

 from the stiffs, claw-like spines 

 scattered along the stems. The 

 scientific name is derived from the 

 Greek, ake, meaning point, in ref- 

 erence to the thorns. Acacia has 

 a remarkable ability to survive 

 under adverse conditions and is 

 often planted on desert sand 

 dunes to bind the soil and pre- 

 vent erosion. The young shoots 

 and flowers are browsed to some 



extent in early Spring but the sharp spines prevent it from being extensively 

 eaten, especially when other foliage is available. The bark exudes a gum 

 similar to gum arabic. The flowers are an important source of honey for bees. 



Occurrence. — GflAND CANYON, common on the Tonto and below, 2,500 to 4,500 feet: 

 Kaibab trail on both sides of the Colorado River; Garden Creek below Indian Gar- 

 dens; Clear Creek trail below Phantom Point; Shiriumo Creek. 



Fig. 82. Catclaw acacia (Acacia Crcgei). 



Scotch Broom (Cytisus scoparms Link.). — Erect evergreen shrub; stems 

 angled, sparsely leafy, the leaves divided into 3 leaflets; flowers bright yellow, 

 pea-like, about % inch long, borne singly or in pairs in the leaf-axils; pods 

 flat, the margins hairy. 



This is a well-known ornamental shrub which has escaped from cultiva- 

 tion and has become naturalized, especially in the Northwest. In early 

 Spring certain sections of the drive around the Olympic Peninsula are lined 

 with the bright yellow flowers of these shrubs. The plants are drought re- 

 sistant and their use has been found to be successful in erosion control work. 

 The herbage is poisonous to livestock. 



Occurrence. — OLYMPIC, rare in the park: Lake Crescent. 



