282 Class XIX. Order I. 



304. HIERACIUM. Receptacle naked, dotted ; down 

 simple, sessile ; calyx imbricate, ovate. 



305. KRIGIA. Receptacle naked ; down of five 

 membranous leaves, alternating with five bristles ; 

 calyx simple, many leaved. 



306. SONCHUS. Receptacle naked ; clown simple, 

 sessile ; calyx imbricate, swelling at the base. 



B. Flowers in heads. 



307. ARCTIUM. Receptacle chaffy ; down bristly 

 and chaffy ; corolla floscular ; calyx globular with 

 hooks on the top of the scales. 



308. CNICUS. Receptacle villous ; down feath- 

 ery ; corolla floscular ; calyx swelling, with spinous 

 scales. 



309. ONOPORDON. Receptacle cellular ; down ca- 

 pillary ; corolla floscular ; calyx swelling with spinous 

 scales. 



310. LIATRIS. Receptacle naked ; down feath- 

 ery, coloured ; calyx oblong, imbricated. 



311. VERNONIA. Receptacle naked ; down double, 

 the outer chaffy, inner capillary ; corolla floscular ; 

 calyx ovate, imbricate. 



C. Florets tubular. 



312. BIDENS. Receptacle chaffy, flat ; seeds angu- 

 lar ; clown consisting of awns prickly backward ; 

 calyx nearly equal, invested with leaves. 



313. MIKANIA. Receptacle naked ; down simple; 

 calyx four or six leaved, and four or six flowered. 



314. EUPATORIUM. Receptacle naked ; down sim- 

 ple or rough ; calyx imbricate, oblong ; style longer 

 than the corolla, cloven half way down. 



