WHORLED ROSIN-WEED 



see what the ray-floret of Ileliopsis accomplishes, 

 take a rather mature flower-head, carefully re- 

 move the bracts of the involucre and at the 

 base of each strong, beautiful yellow ray will be 

 found a fine, plump, full-grown akene; thus 

 the ray-floret renders two services instead of 

 one. The books state the facts simply; the 

 rays of Helianthus are neutral, those of Heli- 

 opsis fertile. 



WHORLED ROSIN-WEED. SILPHIUM 



Silphium trifolidtum 



Silphium, Greek, named because of its resinous 

 juice. 



A tall, perennial. Sunflower-like plant, with 



large, yellow flower-heads borne in corymbose 



panicles; found in fence corners, open fields, and 



roadsides. Middle West and southward; not 



reported from New England, where its place is 



taken by Silphium perfolidtum, escaped, the 



books say, from gardens. 



Stem. — Three to six feet high, growing in clumps; 

 smooth, often purple with a plum-like bloom, corym- 

 bosely branched at the summit. When broken gives 

 a resinous juice and pleasant fragrance. 



21 



