﻿436 COMPOSITtE. Cacalia. 



163. SENECIO. Linn. ; Less. syn. p. 391 ; DC. prodr. 6. p. 340. 

 feet, or radiate ; the rays pistillate. Scales of the involucre in a single series, 



alveolate. Branches of the style in the disk-flowers truncate, the apex only 

 minutely penicillate. Achenia not rostrate or winged, often grooved or ribbed. 



ring in almost every part of the world) ; with alternate leaves, and solitary, 

 paniculate, or corymbose heads. Flowers for the most part yellow. 



In many species of this vast genus (especially in S. coronopus, S. spartioides, S. 

 ampuUaceus, and S. filifolius,) the short hairs or papilla; of the achenia open at the 

 apex when moistened, and emit spiral threads of considerable size, which may be 

 aistmctly observed with a simple lens of low power. 



♦ Annual: raysrume. 



sh^^i ""^'^^^"^^1 discoid f the 'calyculate scales fabout%) ap'pr^ssed, much 



'{t^""'! '^^ Pa '■ ^-^^^^a^l! 513 ^^^EuIlTJl t. ^tlTPurX'^^- P' ' 

 Hook ! fi. Bor.-Am.. 1. p. 331 ; DC ! prodr. 6. p. 341. 



Waste and cultivated grounds in the Northern States! introduced from 



