MIKANIA, climbing hempweed 
Mikania scandens (L.) Willd., p. 1468 
NOTHOCALAIS (see MICROSERIS) 
ONOPORDUM, Scotch thistle 
¢Onopordum acanthium L., Scotch thistle, cotton thistle, p. 1624 
ssp. acanthium 
PALAFOXIA, Spanish needles 
Palafoxia callosa (Nutt.) Torrey & A. Gray, p. 1595 
PARTHENIUM 
Parthenium hispidum Raf., American feverfew, P. 1553 
¢P. hysterophorus L., Santa Maria, P. 1552 
P. integrifolium L., American feverfew, wild quinine, P. 1552 
PICRIS 
*¢Picris echioides L., ox-tongue (Miihlenbach, 1979) 
*+P. hieracioides L., cat’s ear (Mitihlenbach, 1979) 
ssp. hieracioides 
+P. sprengeriana (L.) Poiret, bitterweed, p. 1632 
PLUCHEA, marsh fleabane 
Pluchea camphorata (L.) DC., ors Wa camphor weed, inland 
marsh fleabane , p. 1530 
P. foetida a.) DC., marsh fleabane, stinking fleabane, p. 1530 
var. foetida 
S: Steyermark G: Great Plains Flora M: Mohlenbrock 
