246 PITTONIA. 
the equally good and perhaps too nearly equivalent Edwarsia 
has been as universally ignored. 
To the consideration of this point in the history of the 
classification of the group I shall return later. 
3. Identity of BIDENS FRONDOSA, Linn. 
Introductorily to the discussion of this question must be 
given a sketch of theall important pre-Linnzan bibliography 
of the species. 
B. FRONDOSA, Linn. 
! Eupatorium Canadense, flore luteo, H. R. Par. (1661). 
Chrysanthemum cannabinum Americanum, Moris. H. R. 
Bles. (1635). 
C. cannabinum bidens Americanum caule erecto firmo subru- 
bente, Moris. Hist. iii. 17 (1699). 
Bidens Canadensis latifolia flore luteo, Tourn. Elem. 367 
(1694), also Inst. 462 (1700 
Ceratocephalus tripteris et pentapteris folio, flore luteo discoide, 
Americanus, Vaill. Mem. Acad. 327 (1720). 
In the flora of North America, the nearest approach to 
B. tripartita, the type-species of the genus, is made in this 
familiar B. frondosa. Equally with its Old World homologue 
does our plant typify the Candollean section or subgenus 
Platycarpxa, of which the most salient characteristics are 
the flattened and more or less obovate achenes, never 
either contracted or dilated at summit, and merely two- 
edged and two-awned. But this B. frondosa, at least as to 
the definition given it by authors in general during almost 
the whole of the nineteenth century, is an aggregate of at 
‘Neither the anonymous folio, Hortus Regius eaqui nor Mori 
son's Hortus Regius Blesensis has been seen by me, and the citations 
are here taken upon the authority of Tournefort, 
