770 MISC. PUBLICATION 423, U. S. DEPT. OF AGRICULTURE 



locality, permits comparison with the Arizona specimens. The 

 habit and pubescence are very similar. The flowers of the Arizona 

 specimens are somewhat larger and seem paler, but no other differ- 

 ences are apparent. 



3. Teucrium depressum Small, N. Y. Bot. Gard. Bui. 1: 288. 1899. 



Pinal, Santa Cruz, Pima, and Yuma Counties, 4,000 feet or lower, 

 commonly in wet soil along streams, March to May. Southern 

 Texas and southern Arizona. 



Arizona specimens have usually been identified as Melosmon 

 cubense (L.) Small {Teucrium cubense L.). 



2. TETRACLEA 



Perennial herbs, with ashy-green foliage and fine rough pubescence; 

 leaves ovate or oblong, mostly toothed; flowers in axillary cymes; 

 calyx equally 5-lobed, the lobes acute or acuminate, longer than the 

 tube, this hemispheric in fruit; corolla at least twice as long as the 

 calyx, the lobes oval, subequal; stamens clearly exserted beyond the 

 corolla, curving up under the upper lobes but not strongly so ; nutlets 

 obovate, pitted, hirtellous. 



Key to the species 



1. Lobes of the mature calyx about 4 mm. long, broadly deltoid, acuminate at 

 apex only, the breadth of the lobe not much less than its length. 



1. T. ANGUSTIFOLIA. 



1. Lobes of the mature calyx 5 to 8 mm. long, narrowly deltoid or deltoid-lan- 

 ceolate, acuminate usually in the upper half, the breadth of the lobe half 

 its length or less 2. T. coulteri. 



1. Tetraclea angustifolia Woot. and Standi., Contrib. U. S. Natl. 



Herbarium 16: 170. 1913. 

 Cochise County near Rodeo, N. Mex., about 4,000 feet (Peebles 

 and Loomis 5378). Southern New Mexico and southeastern Arizona. 

 Doubtfully distinct from the following species. 



2. Tetraclea coulteri A. Gray, Amer. Jour. Sci. ser. 2, 16: 98. 1853. 

 Coconino, Yavapai, Greenlee, Maricopa, Cochise, Santa Cruz, and 



Pima Counties, 4,000 feet or lower, April to August. Western Texas 

 to southern Arizona and Mexico. 



3. ISANTHUS. False-pennyroyal 



Small annual glandular-puberulent herbs, branching throughout, 

 the branches ascending; leaves entire, elliptic, acute, usually equaling 

 or longer than the internodes; flowers axillary; calyx equally 5-lobed, 

 the lobes acute, longer than the tube, the latter hemispheric in fruit; 

 corolla somewhat exceeding the calyx, the lobes oval, subequal; 

 stamens 4, about equaling the corolla, ascending under the upper 

 lobes; nutlets pitted, hirtellous. 



1. Isanthus brachiatus (L.) B. S. P., Prelim. Cat. N. Y. 44. 1888. 



Trichostema brachiatum L., Sp. PI. 598. 1753. 



Hilltop and Fort Apache, Navajo County (Harrison 4893, King 

 12929), Mogollon Escarpment, Coconino or Gila County (Purpus 

 8309) , also in Cochise County. Canada to Georgia, Texas, and eastern 

 Arizona. 



