POLTGONACEOUS GENERA. 17 



Certain Polygonaceous Genera. 



Some twelve years have passed since in the Flora Franciscana, 

 I indicated, though indistinctly, what was then and has ever 

 since been my opinion that the groups subgenerioally known as 

 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 Linnaeus, with his fas- 

 cinating but unphilosophic artificialism, introduced what was 

 fated to be a long epoch of retrogression in the history of natu- 

 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. 



Bistorta (Oaesalpino 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 in 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 Colubrina 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 Bistorta 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 Oaesalpino: Kay, Meth. 1 ed. 68 (1682); Tour- 



Lbaflkts, Vol. i, pp. 17-32, Jan. 5, 1904. 



