630 Rydberg : Studies on the Rocky Mountain Flora 



Craig Mountain near Lake Waha, 1892, Sandberg, MacDongal & 

 Heller, 248. 



Wyoming : Headwaters of Tongue River, Big Horn Moun- 

 tains, 1898, F. Tzveedy, 11. 



7. Balsamorrhiza terebinthacea (Hook.) Nutt. Trans. Am. 



Phil. Soc. II. 7 : 349. 1840 



Heliopsisf terebinthacea Hook. Fl. Bor. Am. 1: 310. 1833. 



In this species, as well as in the next, it often occurs that some 

 of the leaves are not pinnatifid, but merely coarsely dentate. It 

 is a rare plant growing in stony soil in eastern Oregon and western 

 Idaho. 



8. Balsamorrhiza macrophylla Nutt. Trans. Am. Phil. Soc. 



11. 7: 350. 1840 



This grows on rocky hillsides in Wyoming, Utah and Idaho. 



9. Balsamorrhiza hirsuta Nutt. Trans. Am. Phil. Soc. II. 7 : 



349. 1840 



This species is found at an altitude of 1000-2000 m. in the 

 dry regions of Utah to British Columbia and California. 



THELESPERMA Less 



Heads radiate. 



Leaf- segments linear- filiform, I mm. or less wide. 



Annual or biennial ; outer bracts subulate-linear, more than half as long as 



the inner. 



1. T trifidum 



Perennial from a rootstock : outer bracts linear-lanceolate, half as long as the 



inner or less. 



2. T. tenia. 



Leaf-segments linear, over I mm. wide ; plant perennial or the first only biennia . 

 Plant with tap-root, leafy throughout. 3- T - ************* 



Plant with creeping rootstock or woody caudex ; leafy only near the base. 

 Involucre not cleft below the middle ; throat of the disk-flowers cam- 



panulate, shorter than the lobes. 4- ?• ambiguit™. 



Involucre cleft below the middle ; throat of the disk-flowers cylmdra- 

 ceous, longer than the lobes. 5- T* subnudtim. 



Heads discoid ; perennials with rootstock or woody caudex. 



Plant less than 2 dm. high ; involucre with very broad scarious margins. 



6. T. marginatum. 



Plants 3-6 dm. high ; involucre with very narrow scarious margins. 



7. T. grant*. 



