478 



WEED FLORA OF IOWA 



Figure 348 A 



Figure 348B 



Figure 348C 



Fig. 348. Seeds of Snakeroot (Eupatorium urticaefolium) and Joe-Pyeweed 

 (.Eupatorium purpureum) . A. Eupatorium purpureum. B. Achenial hairs 

 of same. C. Eupatorium urticaefolium. 

 (A and C, drawings by Ada Hay den ; B, drawing by S. B. Fracker.) 



Figure 349 1 Figure 349 2 



Fig. 349. 1. Hairs from achenium of Eupatorium villosum. 

 achenium of Eupatorium urticaefolium. 

 (Drawings by S. B. Fracker.) 



Surface of 



False Boneset (Kuhnia eupatorioides L.). 



Achenes oblong, columnar, 10-15-ribbed ; blackish or reddish, base 

 with prominent disklike area marked by circular, somewhat bulging 

 ring; from one-eighth to one-tenth inch in length; pappus of 

 fine tawny colored capillary, somewhat brittle, bristles. The achenial 

 hairs of Kuhnia eupatorioides, according to Miss Mary A. Nichols, 

 are mostly simple and short ; a few duplex hairs also occur. 



Blazing-star {Liatris punctata Hook.). 



Achenes 10-ribbed; slender, tapering to the base; one-quarter 

 to one-third inch long; grayish, pubescent, almost pilose; apex 

 brownish; scar at base indistinct; pappus or numerous plumose 

 bristles. The achenial hairs of Liatris gracilis, according to Miss 

 Nichols, are duplex with an indistinct wall arising from the base. 

 The hairs of L. punctata, according to Mr. Fracker, are duplex 

 and simple. 



