Rydberg : Studies on the Rocky Mountain Flora 630 



Craig Mountain near Lake Waha, 1892, Saiidbcrg, MacDoiigal &■ 

 Hella; 248. 



Wyoming : Headwaters of Tongue Riv^er, Big Horn Moun- 

 tains, 1898, F. Tivcedy, it. 



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



Phil. Soc. II. 7: 349. 1840 



Heliopsis? terebinthacea Hook. Fl. Bor. Am. i: 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. 



II. 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 1 000-2000 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. I. T trifidunt. 



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

 inner or less. 2. T. teune. 



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

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



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. 7'. ambigman. 



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

 ceous, longer than the lobes. 5. T. subimdum. 



Heads discoid ; perennials with rootstock or woody caudex. 



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



6. T. iitargiiiatum. 

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



7. T. gracile. 



