FLOWERING PLANTS AND FERNS OF ARIZONA 365 



Key to the subspecies 



1. Fruiting pedicels spreading at an angle of about 45 (30 to 70) degrees; herbage 

 densely canescent subsp. pa y>oxii. 



1. Fruiting pedicels spreading at an angle of about 75 (60 to 90) degrees (2). 



2. Leaf segments narrowly oblong to linear; plant usually short and branched 

 below ; petals mostly less than 2 mm. long, yellow or whitish. 



SUbsp. HALICTORUM. 



2. Leaf segments ovate to oblanceolate (3). 



3. Herbage canescent: petals whitish to pale yellow; pods mostly 8 to 10 mm. 



long; plant wide-branching from the base subsp. ochroleita. 



3. Herbage green, moderately pubescent; petals yellow; pods mostly about 

 6 mm. long; racemes glabrous subsp. glabra. 



A collection at Betatakin, Navajo County (Peebles and Fulton 

 11911), is cited by Detling under his subspecies paysonii. The speci- 

 mens in question have much the appearance of D. obtusa and do not 

 resemble other forms of D. pin nata. Subspecies haiictorum (Cockerell) 

 Detling (Sophia haiictorum Cockerell) and subspecies glabra (Woot. 

 and Standi.) Detling (Sophia glabra Woot. and Standi.) occur through- 

 out most of the range of the species in Arizona. Subspecies ochroleuca 

 (Wooton) Detling (Sophia ochroleuca Wooton) has been collected in 

 Apache, Gila, Pinal, and Pima Counties. 



2. Descurainia obtusa (Greene) O. E. Schulz, Pflanzenreich IV. 105: 



321. 1924. 



Sophia obtusa Greene, Leaflets 1: 96. 1904. 



This species ranges, in various forms, from Apache County to 

 Mohave County, south to Greenlee and Pima Counties. New Mexico 

 to southern California and northern Mexico. 



Key to the subspecies 



1. Plant glandular, at least in the inflorescence subsp. adexophora. 



1. Plant not glandular (2). 



2. Pods 5 to 9 mm. long subsp. brevisiliqua. 



2. Pods 10 to 20 mm. long subsp. typica. 



Subsp. adenophora (Woot. and Standi.) Detling (Sophia ad enophora 

 Woot. and Standi.) is known from McNary, Apache County (J. 

 Whitehead 1599) and from Prescott, Yavapai County (several collec- 

 tions). Subsp. brevisiliqua Detling has been reported from Flag- 

 staff (Coconino County) and Fort Mohave (Mohave County). 

 Subsp. typica Detling is known from Navajo, Coconino, Mohave, 

 Greenlee, and Pima Counties. 



3. Descurainia sophia (L.) Webb ex Prantl, Engl, and Prantl, 



Pflanzenfem. III. 2: 192. 1892. 



Sisymbrium sophia L., Sp. PL 659. 1753. 



Coconino, Mohave, Graham, Pinal, and Santa Cruz Counties, an 

 abundant roadside weed in some localities. Extensively naturalized 

 in the United States; from Eurasia. 



4. Descurainia californica (A. Grav) O. E. Schulz, Pflanzenreich IV- 



105: 300. 1924. 



Smelowskia (?) californica A. Grav, Amor. Acad. Arts and Sci. 

 Proc. 6: 520. 1865. 



Known in Arizona only by a collection in Segi Canyon. Navajo 

 Indian Reservation (Clute 119). Wyoming to Oregon, south to New 

 Mexico, northeastern Arizona, and California. 



