FLOWERING PLANTS AND FERNS OF ARIZONA 433 



3. Sophora stenophylla A. Gray in Ives, Colo. Riv. Rpt. 10. 1860. 

 Hopi Indian Reservation and Betatakin (Navajo County), 6,000 to 



7,000 feet, June, type from Oraibi (Newberry in 1858). Southern 

 Utah, New Mexico, and northeastern Arizona. 



4. Sophora sericea Nutt., Gen. PL 1: 280. 1818. 



Apache County to Yavapai and eastern Mohave Counties, also in 

 Cochise County, 4,000 to 7,000 feet, often growing in dense colonies, 

 April to June. South Dakota and Wyoming to Texas and Arizona. 



15. THERMOPSIS. Goldenpea 



Plant herbaceous, perennial; stems erect, branching, leafy; leaves 

 3-foliolate, the leaflets large, lanceolate to ovate or somewhat rhombic, 

 the stipules large, foliaceous; flowers large, in rather dense terminal 

 racemes, the petals bright yellow; stamens 10, incurved, separate; pods 

 sessile or nearly so. 



1. Thermopsis pinetorum Greene, Pittonia 4: 138. 1900. 



Apache to Coconino Counties south to Graham, Gila, and Yavapai 

 Counties, 6,000 to 9,500 feet, common in pine forests, May to July. 

 Colorado, Utah, New Mexico, and Arizona. 



A showy plant when in flower, reported to be unpalatable to cattle. 

 The plants spread by rootstocks, forming patches. 



16. CROTALARIA. 65 Rattlebox 



Plants herbaceous or suffrutescent ; leaves unifoliolate or trifoliolate, 

 with stipules; flowers in lateral or terminal racemes, these few- to 

 many-flowered; calyx somewhat bilabiate; petals yellow, the keel 

 curved or bent; stamens dimorphic; pods much inflated, many-seeded, 

 oblong to nearly globose. 



The plants are palatable to livestock. 



Key to the species 



1. Leaves unifoliolate, the leaflet linear, lanceolate, elliptic, oval, or the lowest 

 obovate; stems simple, or branched only near the base; herbage (including 

 the upper surface of the leaves) loosely villous or subhirsute with long, more 

 or less spreading hairs; peduncles lateral, 1- to 3-flowered; calyx 6 to 9 mm. 

 long; corolla pale yellow, scarcely surpassing the calyx; pods sometimes 

 black at maturity 1. C. sagittalis. 



1. Leaves trifoliolate, the leaflets commonly oblanceolate or obovate; stems 

 branched well above the base, rarely simple; herbage strigose-pubescent, 

 the upper leaf surface glabrous; peduncles often appearing terminal as well 

 as lateral, 1- to many-flowered; calyx 3 to 4 mm. long; corolla orange yellow, 

 greatly surpassing the calyx; pods reddish brown at maturity. 



2. C. pumila. 



1. Crotalaria sagittalis L., Sp. PL 714. 1753. 



Cochise, Santa Cruz, and Pima Counties, 4,300 to 6,000 feet, sandy 

 soil usually along brooks, August to October. New England to South 

 Dakota and Texas, southern Arizona, and south to Panama, 



The Arizona forms are: (1) var. blumeriana Senn, differing from typi- 

 cal C. sagittalis in its shorter stems, shorter and relatively broader 



65 Reference: Senn, Harold A. the north American species of crotalaria. Rhodora 41: 317-367. 

 1939. 



