POLTGOKAOEOUS GBNBRA. 23 



flowers, one only in the axil of each bract of the spike, the per- 

 sistent styles, and, more important than all else, the absence of 

 that articulation at base of the leaf -blade which marks Polygo- 

 num., — these are three generic characters, and I propose for the 

 group generic rank under the name Dukavia. The species as 

 far as known have received specific names under Polygonum as 

 follows : D. Califoekica (Meisn. in DC, xiv. 100), Bidwelli^, 

 Grebnei (Wats. Am. Acad. xiv. 394, 395); of the same genus, 

 apparently, is the large suffrutescent species D. Bolandeei 

 (Brewer ex Gray, Am. Acad. viii. 400). 



For the small assemblage of the convolvulaceous Polygoneaa, 

 long ago aptly denominated Climbing Buckwheat by country 

 people — and surely less unreasonably reduced to Fagopyrum by 

 pre-Linnseans, than to Polygonum by Linnseus — I indicated in 

 the Flora Franciscana that the generic name is Bildekdykia, 

 Dumortier. 



I do not admire uncouth personal names in botany, and regret 

 that Tiniaria, used by Mr. Small, has not priority. 



Dumortier, whose Florula Belgica is very scarce — and as im- 

 portant for Polygonese in particular as it is rare — places these 

 plants, where they truly seem to belong, next to Fagopyrum ■ 

 and in his view the group has a better claim to the status of a 

 genus, than either Bistorta or Persicaria, both of which remain 

 with him but sections of Polygonum. 



Two species, B. Convolvulus and dumetorum are named by 

 him. Some of the others that go with them are B. scandens 

 (Linn. Sp. 523), oilikodis (Michx. Fl. i. 341), CRISTATa (E. & 

 G. PI. Lindh, 51) and ptbrocarpa (Wall. Catal. n. 1690). 



The Japanese P. muliifiorum, commonly associated with the 

 above I have not seen; but the description reads as if it might, 

 perhaps, constitute a generic type. 



During some sixteen centuries was Persicaria recognized 

 universally as a genus distinct from Polygonum. Liunseus, the 

 great father of confusion as to genera of plants, reduced the 

 species to Polygonum ; but ever since there has been a succession 

 of authors who have protested against this, and reasserted Per- 



