COMPOSITE FAMILY 



COMPOSITAE 



ILLINOIS IRONWEED 



Vernonia illinoensis Gleason 



The Illinois Ironweed is common on prairies and in other open 

 places from Ontario to Illinois, Kentucky and Texas. It is peren- 

 nial and has a stout, densely hairy stem that grows 3-6 feet high 



and is quite leafy. The leaves 

 are quite similar and densely 

 hairy on the lower surface. 



This plant blooms in bril- 

 liant display from August to 

 October. The inflorescence is 

 usually quite compact as the 

 heads have short peduncles. 

 The involucre is rather short 

 cylindric and its bracts are 

 more or less hairy, purplish and 

 arranged in several series. The 

 receptacle is flat and not 

 chaffy. The 30-60 red-purple flowers of each head 

 are tubular and perfect. The akenes are cylindri- 

 cal and smooth or nearly so. The pappus is purple 

 and double, the outer part consisting of small 

 scalelike bristles and the inner part of a large 

 number of long threadlike bristles. 



The Western Ironweed, Vernonia fasciculata 

 Michx., is more often found on low grounds and 

 wet prairies, from Ohio to Minnesota, Nebraska and 

 Oklahoma. The blooming season is July to Septem- 

 ber. The plant is about the same size as V. illinoensis 

 but the stem is smooth or nearly so. The leaves are very 

 narrowly lanceolate and are smooth or nearly so on 

 both sides. They are 3-6 inches long and are usually less than one- 

 half inch wide. The heads are smaller than in the Illinois Ironweed, 

 being only 20-30-flowered, but otherwise they are similar. 



The New York Ironweed or Flat Top, P'ernonia noveboracensis 

 Willd., has somewhat hairy to smoothish stems that rise 3-9 feet 

 from the moist soil of wooded bluffs in the Illinois river system. The 

 3-10-inch leaves are lanceolate or narrowly oblong, fine toothed, more 

 or less hairy beneath and narrowed into petioles. The peduncled 

 heads are mostly 30-40-flowered, deep purple or rarely white. Bracts 

 of the hemispheric involucre are brownish purple or greenish and 

 have spreading awl-shaped tips usually 2-3 times their own length. 

 The pappus is purplish or rarely green. 



336 



