FLOWERING PLANTS AND FERNS OF ARIZONA 357 



1. Dithyrea californica Harv., London Jour. Bot. 4: 77. 1845. 

 Mohave and Yuma Counties, 1,800 feet or lower, sandy soil, plains 



and mesas, March to April. Southern Nevada and western Arizona 

 to Baja California. 



2. Dithyrea wislizeni Engelm. in YVisliz., Mem. North. Mexico 96. 



1848. 



Apache County to Mohave County, south to Graham, Pinal, 

 Maricopa, and Yuma Counties, 1,000 to 6,000 feet, sandy soil, often 

 along streams, February to August. Colorado and Utah to Arizona 

 and northern Mexico. 



Occasional in Arizona is var. grijfiihsii (Woot. and Standi.) Payson 

 (D. griffiihsii Woot. and Standi.) with glabrous pods but not con- 

 sistently with narrow entire leaves. It is stated that D. wislizeni is 

 used by the Hopi Indians in treating wounds. 



23. PHYSARIA « 



Plants small, cespitose, more or less silvery-lepidote; leaves mostly 

 basal, or the basal leaves much larger than the stem leaves, the blades 

 orbicular to spatula te; petals narrow, yellow; pods didymous, bladder- 

 like, deeply notched at apex; seeds usually 2 or more in each cell. 



Key to the species 



1. Style 2 to 3 mm. long; replum of the pod lanceolate 1. P. xewberryi. 



1. Style 6 to 8 mm. long; replum of the pod oblong 2. P. chambersii. 



1. Physaria newberryi A. Gray in Ives, Colo. River Rpt. 6. 1860. 

 Apache, Navajo, and Coconino Counties, 6,000 to 7,000 feet, May, 



type from Tegua, Hopi villages, Navajo County {Newberry in 1858). 

 Utah, Nevada, New Mexico, and northern Arizona. 



2. Physaria chambersii Rollins, Rhodora 41: 403. 1939. 



Near Pipe Springs, Mohave County, 5,000 feet, April to May 

 {Peebles and Parker 14709). Utah, Nevada, and northwestern 

 Arizona. 



24. LESQUERELLA. 50 Bladderpod 



Plants annual or perennial; herbage stellate-canescent; leaves 

 largely basal, the blades entire to sinuate-dentate; flowers in loose 

 racemes, the petals yellow, or white tinged with purple; pedicels 

 elongate in fruit; styles persistent; pods inflated, globose or ovoid, 

 the valves nerveless; seeds 2-rowed in each cell. 



The roots of one species, perhaps L. intermedia, are reported to be 

 used by the Hopi Indians as an antidote for rattlesnake venom. 



Key to the species 



I. Plants annual, green and sparsely pubescent to densely silvery canescent; 

 leaf blades lanceolate, oblanceolate, or spatulate, entire (exceptionally 

 sinuate-dentate), the basal leaves sometimes lyrate, the stem leaves 2 to 12 

 mm. wide; petals 6 to 8 mm. long, bright yellow, sometimes fading reddish; 

 pedicels in fruit spreading, becoming sigmoid; pods globose or nearly so, 

 about 4 mm. in diameter, somewhat longer than the style, typically 

 glabrous and short-stipitate 1. L. gordoni. 



*> Reference: Rollins. Reed C. the cruciferous genus physaria. Rhodora 41: 392-415. 1939. 



50 Reference: Payson. F. B. MONOGRAPH OF THE GENUS LESQUERELLA. Mo. B<'t. Car^!. Ann. 8: HG- 

 236. 1921. 



