COMPOSITES 445 



E. perfoliatum. Linn. Boneset. Thoroughwort. Fig. 171. Two to 4 ft., 

 hairy: leaves opposite and sessile, lanceolate: flowers white, in clusters. 



36. VERNONIA. IRONWEED. 



Coarse perennial herbs, with tall strong leafy stems: leaves alternate 

 (seldom opposite), sessile: flowers 15 to many in a head, heads corymbed, 

 all tubular, perfect, purple (rarely white or pink); involucre shorter than 

 flowers, with several series of scales; receptacle not chaffy; pappus double, 

 the inner series bristle-like, the outer of short, small, scale-like bristles: 

 achenes cylindrical, several-ribbed. 



V. novaboracensis, Willd. A coarse weed, 3-6 ft. : heads about K in- 

 long: bracts of involucre, some or all, with slender long or awned flexuous 

 points, brownish purple: leaves many, rough, lanceolate or lance-oblong, 

 2-9 in. long, serrulate, sessile, all along stem: flowers deep purple in 

 spreading, flat-topped cymes: achenes somewhat hairy. Late summer. 



V. fasciculata, Michx. Tall, coarse weed, 3-10 feet, with deep purple 

 flowers in heads (20-30-flowered), corymbed; involucre campanulate, 

 scales usually obtuse, not awn-like. Summer and autumn. 



