SEQKBGATBS OF RHUS. 133 



A Lower Oalifornian species, collected by Purpus and dis- 

 tributed for a variety of T. diversiloba, to which it is in no wise 

 related. It may represent a Mexican type of the genus, and one 

 farther removed from the Oalifornian type than is even Atlantic 

 slope Toxicodendron. 



T. PHASBOLOiDES. Akin to the last, but at least sometimes 

 rooting at the nodes and climbing, the internodes not elongated 

 but leaves and flower-clusters approximate : leaflets rhombic- 

 lanceolate, abruptly acuminate, entire or coarsely dentate : pani- 

 cles short, ascending : fruits larger, spherical, not depressed. 



Turucahi, Sonora, Mexico, C. V. Hartman, n. 102, of the 

 1894, collection, as in U. S. Herb. No. 589 of the same collec- 

 tion, from St. Diego, 1891, is probably the same. 



T. LABTBTIRENS. Stcms long and slender, not upright, more 

 or less geniculate, rooting at some nodes, the bark light gray, 

 puberulent : foliage copious, large, of a peculiarly vivid light- 

 green : leaflets thin, ovate-lanceolate to lanceolate, acuminate 

 but the very apex obtuse, entire or more or less plainly sinuate- 

 lobed, the terminal 2 to 3 inches long, the laterals shorter and 

 unequal-sided, both faces glabrous but the petioles pubescent : 

 panicles slender, ample and many-flowered, erect or ascending : 

 fruit unknown. 



Santo Catalina Mountains, Arizona, 5 May, 1894, J. W. 

 Tourney. 



T. Arizokicum. Slender as the last, the branches tortuous 

 but not geniculate, neither showing only aerial roots : leaves 

 larger, dark green, firm and subcoriaceous, the leaflets elongated- 

 oval, abruptly tapering to an apex, nevertheless, very obtuse, the 

 terminal 2 J to 4i inches long, the pair not very inequilateral, 

 all entire, glabrous above, hirtellous along the veins beneath but 

 hardly as to the petiolules: panicles small, seldom of much 

 more than one raceme: fruit unknown. 



Fort Huachuca, Ariz., spring of 1890, Dr. Bdw. Palmer. 



T. EXIMIUM. Branches long, slightly tortuous, evidently 

 more or less reclining, only the growing parts seen, these not 

 striate, greenish-gray, velvety-puberulent : leaves 5 or 8 inches 

 long, rather short-petioledj terminal leaflet 2 J to 3 J inches long, 



