310 Plants collected during a journey 



202. Prenanthes juncea, Pursh fl. ii. p. 498. Nutt. 

 gen. ii. p. 123. On the Platte and Missouri. 



Obs. Near the Rocky Mountains, Dr. James collected two 

 species of a genus allied to Prenanthes, but differing in their 

 plumose and sessile pappus. They will probably hereafter 

 be referred to a new genus. Their principal characters are 

 as follows: 



1. P. ? pauciflora, caule ramoso, flexuoso, superne pani- 

 culato, ramulis unifloris, floribus erectis ; foliis lineari-lance- 

 olatis, runcinatis, glabris ; calycibus quinquefloris. 



2. P.? tenuifolia, caule ramoso, glabro ; foliis linea- 

 ribus, integerrimis; panicula laxa terminali; floribus erectis J 

 calycibus quinquefloris. 



203. Cakduus (Cnicus) altissimus, Willd. sp. pi. iii. 

 p. 1671. Pursh fl. ii. p. 506. On the Missouri. 



204. Liathis cylindrica, Mich. fl. ii. p. 93. ? Ell.sk. 

 ii. p. 276. L. squarrosa, Torrey in Sill. jour. v. p. 66. 

 Sources of the Platte ? 



Obs. Dr. James' specimens resemble those collected by 

 Captain Douglass, in Cass' Expedition, except in not being 

 above ten inches high, with the leaves hairy on the margin. 



205. Vernonia altissima, /3 ? marginata ; caule glabro; 

 foliis angusto-lanceolatis, glabris, integerrimis ; corymbo fas- 

 tigiato ; involucro turbinato-hemispherico ; squamis ovatis, 

 acutis, arachnoideo-ciliatis, mucronulalis, arete appressis. 



Desc. Stem terete, striate, smooth. Cauline leaves narrow, lanceo- 

 late, very smooth on both sides, entire, glandularly-punctate under a lens, 

 without nerves. Corymb about 40-flowered, fastigiate. Heads as large 

 as in V. noveboracensis, pedunculate. Involucrum subturbinate, about 16- 

 flowered. Scales ovate, the upper ones slightly acuminate, mucronate, 

 greenish, bordered with red ; margins connected and ciliate, with an 

 arachnoid web. Receptacle naked. Corolla purple. Pappus double ; 

 the exterior scarcely perceptible, paleaceous ; the interior hairy, reddish. 

 Seed smooth. 



Hab. On the Arkansa ? 



Obs. It is probable that the present species is distinct from 



