POLYGONACEOUS GENERA. 17 
Certain Polygonaceous Genera. 
Some twelve years have passed sincein the Flora Franciscana, 
I indicated, though indistinctly, what was then and has eyer 
since been my opinion that the groups subgenerically known a8 
Bistorta, Persicaria, and Bilderdykia ought all to obtain recog- 
nition as proper genera; a rank which had been universally 
conceded to them up to the time when Linnæus, with his fas- 
cinating but unphilosophic artificialism, introduced what was 
fated to be along epoch of retrogression in the history of natn- 
ral classification. 
During the last nine years, in my herbarium, these and other 
genera allied to them, have been segregated, each under its Own 
name; and I now desire that a more open presentation of my 
ideas along this line of study should be made without further 
delay. 
BistortTa (Cesalpino de Plantis, 167, (1583) has long seemed 
to me one of the most pronounced generic types in this whole 
family, in view of its strong habital and vegetative characters. 
In these respects it has more in common with Lapathum (erro- 
neously called Rumex iu these days) than with any other genus. 
In all but the inflorescence it closely imitates the dock in aspect, 
and like it the herbage wants the pellucid dots or glands that 
mark the genus Persicaria; and this kind of vegetative charac- 
ter is allowed great weight in plant classification generally. 
The contortions of the root in this genus are peculiar, and 
early gave rise to such generic synonyms as Co/ubrina and Ser- 
pentaria; while in England it was of old commonly called 
Snakeweed, as Gerarde testifies. This quaint old author, by the 
way, reports that the herbage was used in some parts of Eng- 
land “as an excellent pot herbe,” and also adds, what all do not 
know, that “it is called Brsrorra of his writhed rootes.” 
The following are some of the authors of renown who may 
be consulted upon this type in the rank of a genus, and under 
this name, since Cxsalpino: Ray, Meth. 1 ed. 68 (1682); Tour- 
LearLerTs, Vol. i, pp. 17-32, Jan. 5, 1904. 
