(212) 
On the other hand the typical form, extremely abundant on the 
prairies of central Illinois, is easily recognized from V. mdéssurica 
by the smaller heads, the less tomentose leaves, the shorter invo- 
lucre, the blunter, more arachnoid scales, and the purple pappus. 
The evidence from the geographical distribution of the two is alone 
sufficient to warrant the separation of the species. V. medssurica 
is typically an Ozarkian plant, and no members of the Ozarkian 
ora have arange even approaching that of V. cllénoensis. The 
latter is characteristic of the eastern arm of the Prairie province. 
Its distribution is therefore similar to that of V. fasciculata, and 
since it also somewhat resembles that species in the color of the 
scales and pappus, the sharper serration and the relatively little 
pubescence of the leaves, it seems probable that its affinities are 
with the group Fasciculatae rather than with the Interiores. 
Specimens from Ontario have been distributed with the herbarium 
name V. Macounzi Britton. They represent an extreme form with 
rather rugose, thinly pubescent leaves, and with reduced inflores- 
cence, and should not be taken as a specific type, unless the form is 
eventually regarded as distinct from the western psilophyte. 
(vi) Species-group Jnteriores 
Heads large, 18-55-flowered; involucral scales appressed, at 
least at the base, spreading or recurved at the apex, usually acute 
or acuminate, more or less pubescent; pappus tawny or purple- 
tawny; leaves broad, serrate, tomentose beneath. The two species 
are characteristic of the Ozark region, and extend but little beyond 
its limits north into Iowa and south into Texas. 
82. VERNONIA INTERIOR Small, Bull. Torrey Club 27: 279. 
Involucral scales greenish-purple, lanceolate, acute or short- 
acuminate, thinly canescent and ciliate, regularly imbricated, ap- 
pressed at ‘the base, the tips erect or very slightly spreading. 
Type locality: ‘*On plains and prairies, Missouri and Kansas 
south to Texas.” 
Distribution: from southeastern Nebraska and southern Iowa 
south to central Texas. 
A well-marked species of little variability, except in the invo- 
lucral scales. One sheet in the National Herbarium, Crevecoeur 
30, from Onaga, Kansas, has few heads in a dense corymb, with 
