FLOWERING PLANTS AND FERNS OF ARIZONA 511 



pine forests, June to September. New Mexico, Arizona, and northern 

 Mexico. 



*3. Linum kingii S. Wats, in King, Geol. Expl. 40th Par. 5: 49. 1871. 



Cathartolinum kingii Small, North Amer. Fl. 25: 73. 1907. 



Not known to occur in Arizona but is found in southern Utah, near 

 the northern border of Arizona. 



4. Linum puberulum (Engelm.) Heller, Plant World 1: 22. 1897. 



Linum rigidum Pursh var. puberulum Engelm. in A. Gray, 



PL Wright. 1: 25. 1852. 

 Cathartolinum puberulum Small, North Amer. Fl. 25: 80. 



1907. 



Apache County to Coconino County, south to Cochise, Santa 

 Cruz, and Pima Counties. 3.500 to 6,500 feet, April to July. Colorado, 

 Utah, New Mexico, and Arizona. 



Scarcely more than a variety of L. rigidum, differing chiefly in its 

 denser puberulence and in having the apex of the pedicel not or only 

 slightly cupulate. 



5. Linum aristatum Engelm. in Wisliz., Mem. North. Mex. 101. 1848. 



Cathartolinum aristatum Small, North Amer. Fl. 25: 83. 1907. 



Apache County to Hualpai Mountain (Mohave County), 5,000 to 

 8,000 feet, plains and mesas, mostly in sandy soil, May to September. 

 Colorado and western Texas to northern Arizona and Mexico. 



The var. australe (Heller) Kearney and Peebles (L. australe Heller) 

 has the same range in Arizona as the typical form and also extends 

 farther south, to the Rincon Mountains (Pima County) . As compared 

 with the typical form it has shorter outer sepals, more distinctly 

 dentate inner sepals, more diffusely branched stems, and usually ser- 

 rulate leaves, the leaves being commonly entire in the typical form of 

 the species. L. aristatum is reported to be used by the Hopi Indians 

 in cases of childbearing. 



58. ZYGOPHYLLACEAE. Caltrop family 



Plants herbs or shrubs; leaves digitately or pimiately compound, 

 mostly opposite, the leaflets entire; flowers perfect, regular or nearly 

 so; sepals and petals 5; stamens 10, in 2 whorls, the filaments separate; 

 ovary 2- to 6-celled, sometimes splitting in fruit into as many or 

 twice as many nutlets; styles not separating from the column. 



Key to the genera 



1. Leaves 3-foliolate; stipules spiny; petals purple; plant suffrutescent. 



1. Fagoxia. 

 1. Leaves 2-foliolate, or pinnate with numerous leaflets; stipules not spiny; petals 

 yellow or orange (2) . 

 2. Plant shrubby, very glutinous, strong-scented: leaflets 2, divaricate: stamens 



with scalelike appendages: fruits densely villous 2. Larrea. 



2. Plants herbaceous, not glutinous or strong-scented: leaflets 4 or more pairs; 

 stamens not appendaged: carpels dorsally tuberculate or spiny (3 . 

 3. Fruit flat, radiate, breaking up into 5 nutlets, each with 2 strong dorsal 

 spines and containing 2 or more seeds, these separated by transverse 



septa 3. * Tribtlus. 



3. Fruit hemispheric or higher, not radiate, breaking up into more than 5 



nutlets, these nut spiny, 1-seeded 4. Kallstroemia. 



286744°— 42 33 



