FLOWERING PLANTS AND FERNS OF ARIZONA 347 



2. Lepidium fremontii S. Wats, in King, Geol. Expl. 40th Par. 5: 30. 



1871. 



Mohave and Yuma Counties, 3.000 feet or lower, dry sandy soil of 

 plains and mesas, March to May. Southwestern Utah and western 

 Arizona to southeastern California. 



The only really shrubby species in Arizona, attaining a height of 1 

 meter. The fragrant flowers are showy for the genus. 



3. Lepidium thurberi Wooton, Torrey Bot. Club Bui. 25: 259. 1898. 

 Graham County to Yavapai County, south to Cochise, Santa Cruz, 



and Pima Counties, 5.000 feet or lower, February to September. 

 New Mexico and Arizona. 



A common roadside weed in central and southern Arizona, conspicu- 

 ous because of its relatively large, pure-white flowers. 



4. Lepidium montanum Nutt. ex Ton*, and Gray, Fl. North Amer. 1: 



116. 1838. 



Apache County to Mohave and Yavapai Counties, 3,000 to 7.000 

 feet, April to September. Colorado to Oregon, south to Texas, 

 Arizona, and California. 



Occurs in several forms, of which the commonest in Arizona is var. 

 canescens (Thell.) C. L. Hitchc, characterized by herbaceous stems, and 

 cinereous puberulence of the herbage, and by having some of the leaves 

 (often aU of them below the inflorescence) pinnatifid. Commonly 

 suffrutescent forms are: var. glabrum C. L. Hitchc, with entirely 

 glabrous herbage, in the Grand Canyon-Flagstaff region, and var. 

 jonesii (Rydb.) C. L. Hitchc. (L. jonesii (Rydb.) with sparsely pubes- 

 cent herbage, Apache to Coconino and Yavapai Counties. A moder- 

 ately puberulent, often suffrutescent form with most of the leaves 

 entire is var. cdyssoides (A. Gray) Jones (L. alyssoides A. Gray), known 

 from Holbrook (Navajo County) and from Crater Mound and House 

 Rock Valley (Coconino County). A collection at Fort Verde, Yava- 

 pai County (Mearns 309) was referred by Hitchcock doubtfully to var. 

 integri folium (Nutt.) C. L. Hitchc. (L. integrifolium Nutt.), a form with 

 thick leaves, all of them entire. 



5. Lepidium lasiocarpum Nutt. ex Torr. and Gray, Fl. North Amer. 1: 



115. 1838. 

 Almost throughout the State 4.000 feet or lower, commonly in sandy 



soil, January to April. Southwestern Colorado to Arizona and 

 California, southward into Mexico. 



The typical form of the species occurs almost everywhere in Arizona. 

 Differing from this only in having the hairs of the pods more or less 

 pustular at base is var. wrightii (Gray) C. L. Hitchc. (L. wrightii 

 A. Gray), which has been collected in Maricopa, Pinal, Santa Cruz. 

 and Pima Counties, also on Williams River. The var. georginum 

 (Rydb.) C. L. Hitchc. (L. georginum Rydb.), which has the pedicels 

 pubescent only on the upper side, instead of pubescent on both sides 

 as in the other forms, is occasional in Santa Cruz and Pima Counties. 



6. Lepidium oblongum Small, Fl. Southeast, U. S. 468. 1903. 



Lepidium Hpinriatifidum of authors. Not of Desvaux ? 



Common in waste ground near Sacaton (Pinal County), 1,300 feet. 

 Arkansas to Texas, Arizona, and California, probably introduced 

 from South America. 



