56 Notes on Minnesota Species of Laciniaria. 



Adenostyliiiae of the tribe Eupatoriaceae, A tribe which has 

 but one genus on the European continent, and that they are 

 all typical North American prairie composites which attain 

 their greatest abundance in the southern portion of their 

 range. 



Points like these tend more than anything else to throw 

 light on the origin of the American composites and help to 

 explain their present distribution over the North American 

 continent. 



We often turn aside from the mo»e far-reaching points of 

 relationship and distribution when studying a group of 

 plants and question their utility. 



In the present case a most pleasing answer can be given. 

 First of all their beauty attracts our attention, and to such 

 a degree that many species are artificially grown both in 

 America and in the botanic gardens of the continent. Then 

 again the corm or rootstock, particularly that of Laciniaria 

 scariosa (L.) Hill, is largely used in medicine and as a substi- 

 tute for vanilla. 



SYNOPSIS OF MINNESOTA SPECIES. 



§1. Pappns very plumose; heads 16-20 flowered, cylin- 

 draceous with turbinate base ; bracts of the involucre much 

 imbricated with herbaceous tips if any ; lobes of the corolla 

 pilose inside; leaves all linear and rigid, the lower elongated 

 and grammiform. 



1. L. squarrosa ( L.) Hill. — Pubescent or partly glabrous; 

 stem stout, 6 to 20 inches high; heads few or sometimes 

 numerous in a leafy spike or raceme ; bracts of the involucre 

 all lierbaceous, lanceolate, rigid and with somewhat 

 pungent tips, squarrose-spreading and prolonged. Dry 

 gravelly or sandy soil, Ontario to Minnesota, Nebraska^ 

 Texas and Florida. 



In the southern portion of the state, rare. 



2. L. cylindracea (Michx.) O. K.— Most glabrous, a foot 

 high; heads few or several, 16-20-flowered, an inch or less 

 long; bracts of the involucre all appressed, barely herbace- 

 ous, rounded and abruptly mucronate at the tip, the outer- 

 most very short. Dr^^ prairies and woodlands, Ontario and 

 Michigan to Minnesota and Missouri. 



