342 MISC. PUBLICATION 4 2 3, U. S. DEPT. OF AGRICULTURE 



County), 4,000 to 5,000 feet. Colorado, Utah, New Mexico, and 

 northern Arizona. 



2. THELYPODIUM « 



Plants annual or biennial, glabrous or nearly so; stems usually 

 freely branched, each branch ending in a short and rather crowded 

 raceme; basal leaves very large; stem leaves sessile or nearly so but 

 not clasping, the blades entire; pedicels conspicuously widened and 

 flattened at base; petals with slender claws; pods long and slender, 

 torulose. 



Key to the species 



1. Pedicels not more than 5 mm. long; petals white; stipe of the pod 1 to 3 mm. 



long 1. T. RHOMBOIDEUM. 



1. Pedicels 5 to 10 mm. long; petals purplish pink or white; stipe not more than 

 1 mm. long 2. T. lilacinum. 



1. Thelypodium rhomboideum Greene, Pittonia 4: 314. 1901. 



Pleurophragma platypodum ~Rydh., Torrey Bot. Club Bui. 34: 



434. 1907. 

 Pleurophragma rhomboideum O. E. Schulz, Bot. Jahrb. 66: 98. 



1933. 



Painted Desert, Coconino or Navajo County, "abundant," (Cluie 

 82), also in Havasu Canyon, Coconino County, "occasional" (Clover 

 4379), July. Utah and northern Arizona. 



The plant bears a considerable resemblance to Stanleyella wrightii. 



2. Thelypodium lilacinum Greene, PL Baker. 3: 9. 1901. 

 "Arizona," without definite locality (Palmer in 1869), July to 



September. Nebraska to Washington, New Mexico, Arizona, and 

 California. 



3. HESPERIDANTHUS 



Plant perennial, glabrous and somewhat glaucous; stems tall, 

 branched above; stem leaves sessile or nearly so, linear, entire; flowers 

 rather large; sepals firm, erect, the outer ones strongly gibbous at 

 base; petals purplish pink; pods slender, terete, short-stipitate. 



1. Hesperidanthus linearifolius (A. Gray) Rvdb., Torrev Bot. Club 

 Bui. 34: 434. 1907. 



Streptanthus linearifolius A. Gray, Amer. Acad. Arts and Sci. 

 Mem. ser. 2, 4: 7. 1849. 



Apache, Navajo, and Coconino Counties, south to Cochise and 

 Pima Counties, 3,000 to 8,000 feet, common in chaparral and pine 

 forests, June to September. Colorado to Arizona and northern 

 Mexico. 



4. PENXELLIA 



Plants biennial, pubescent below with forked hairs; stems slender, 

 erect, simple or sparingly branched with erect branches; basal leaves 

 oblanceolate, dentate, the stem leaves narrow, mostly entire; flowers 

 small, in long narrow racemes; sepals greenish; petals whitish, 2 to 

 3 mm. long; pods slender, terete, erect. 



45 Reference: Payson. E. B. a monographic study of thelypodicm and its immediate allies. 

 Mo. Bot. Gard. Ann. 9: 233-324. 1922. ( Thelypodium, pp. 260-282.) 



