90 

 A NEW HYMENOPAPPUS FROM COLORADO 



By Geo. E. Osterhout 



y Hymenopappus polycephalus sp. nov. 



Perennial from a tap-root; stems one to several, 4-6 dm. high, 

 tomentose, becoming glabrate, leafy at the base and less so to the 

 middle, the stem having 6-8 leaves; much alternately branched, 

 the branches beginning near the base; leaves 10-12 cm. long, 

 pinnately or bipinnately parted into very narrowly linear and 

 rather distant divisions, the upper smaller; inflorescence panic- 

 ulate, the heads long peduncled and single at the ends of the 

 branches; the bracts narrowly obovate, 5-6 mm. long, tomentose, 

 somewhat thickened in the middle, with a rather broad scarious 

 margin; flowers yellow, the throat of the corolla broadly cam- 

 panulate, scarcely 1.5 mm. long, the reflexed lobes about a third 

 as much, the tube of the corolla about as long as the throat, 

 glandular, the pappus about half the length of the tube; the 

 achenes narrowly obpyramidal 4 mm. long, long villous, but the 

 pappus not covered by their villosity. ■» 



Another perennial, yellow-flowered, Hymenopappus has been 

 described from Colorado, H. cinereus Rydb., but that is a smaller 

 plant, with fewer heads of flowers, and is less leafy. Dr. Ryd- 

 berg's description says: "Stem about 2 dm. high, branched, with 

 2-4 leaves." The close relationship of Hymenopappus poly- 

 cephalus, however, is not with H. cinereus but with H. tenuifolius 

 Pursh. It is as high and as leafy as H. tenuifolius, but the 

 flowers are yellow, not dull white, and it is a perennial, not a 

 biennial. The achenes are very similar to those of H. tenuifolius. 



H. polycephalus is found on the foothills of the eastern side of 

 the mountains of northern Colorado at an altitude of 6,000 to 

 7,500 feet. It is plentiful in the open country about Livermore, 

 Larimer Co., Colo., and northward to Dale Creek, and on into 

 Wyoming, I think. It blossoms from the last of June to early 

 in September. I have collected it a number of times, and for a 

 time thought it belonged with H. tenuifolius. The type speci- 

 mens were collected in the vicinity of Livermore, Larimer Co., 

 Colo., Aug. lo-ii, 1917, No. 5680. 



Windsor Colo. 



