615 Rydberg : Studies on the Rocky Mountain Flora 



By removing Stenotus lineavifolins Torr. & Gray and S. interior 

 Greene, which constitute a good genus, the genus Stenotus be- 

 comes a very natural one, with only one somewhat aberrant mem- 

 ber, ^. lanuginosus which approaches Pyrrocoma imdoides and its 

 relatives in habit. 



The Rocky Mountain species are distinguished as follows : 



Plant glabrous or puberulent ; leaves firm and evergreen. 



Leaves linear to filiform, i. S. sienophyllus. 



Leaves mostly oblanceolate. 

 Bracts lanceolate, acute. 

 Plant puberulent. 



Bracts in 3 series, broad, with broad scarious margins. 



2. S. acaulis. 

 Bracts in 2 series, narrow, with narrow scarious margins. 



3. .S*. Andersonii. 



Plant glabrous. 



Stem-leaves oblanceolate, 1-2 cm. long. 4. S. caespitostis. 



Stem-leaves linear, 4-7 cm. long. 5. S. falcatus. 



Bracts oval or oblong, very obtuse. • 6. S. aniierioides. 



Plant floccose ; leaves softer, not evergreen. 7. S. hvuigino.us. 



1. Stenotus stenophyllus (A. Gray) Greene, Erythea, 2 : 72. 



1894 

 Aplopappns stenophyllus A. Gray, U. S. Expl. Exp. 17 : 347. 



1862-74. 



This species grows on stony hills and mountains and ranges 

 from western Idaho and Washington to California. 



2. Stenotus acaulis Nutt. Trans. Am. Phil. Soc. II. 7 : 334. 



1840 



Chrysopsis acaulis Nutt. Journ. Phil. Acad. 7:33. 1834. 

 . Aplopappns acaulis A. Gray, Proc. Am. Acad. 7 : 353. 1867. 



This is a rather common species, growing on dry rocky hills 

 and mountains at an altitude of 1000-2500 m., from Saskatche- 

 wan and Washington to Wyoming and California. 



3. Stenotus Andersonii sp. nov, 



A puberulent, cespitosc, but less woody perennial than the pre- 

 ceding and the three next following species. Flowering stems 

 about I dm. high, leafy at the base, few-leaved above : leaves nar- 

 rowly oblanceolate, not very rigid, distinctly 3-ribbed, 3-5 cm. 

 long, 3-4 mm. wide : bracts narrowly lanceolate, acute, glandular 



