POLYGONACEOUS GENERA. 21 
the type specimens from Cameron Pass at an altitude of 11,700 
feet, collected by C. F. Baker, 16 July, 1896. 
Of all the new species of Bistorta here proposed the types are 
in my own herbarium ; and doubtless many more species not yet 
described exist in other herbaria. The characters on which 
species may be established—those of rootstock, leaf, spikes and 
especially their bracts—are herein sufficiently indicated, and 
other students of the group will carry forward the work here 
begun upon our North American forms. 
The genus is one of many which while but feebly represented 
in the floras of Europe and eastern North America, exhibit a 
multiplicity of species in those of both Asia and western America; 
and I next subjoin a partial list of such Asian species as accord 
perfectly with the type as to vegetative characters and a simple 
and terminal spike; taking for their names under BISTORTA the 
same that have been already assigned them under Polygonum : 
B. BULBIFERA (Royle, Trans. Linn. Soc. xviii. 94), SPHAEROS- 
TACHYA and STENOPHYLLA (Meisn. Monogr. 53, 52), CONFUSA 
(Meisn. in Wall. PI. As. Rar. iii. 53), PERPUSILLA (Hook. f. Ic. 
Pl. t. 1490). 
Also Asian, and of this genus as to habit and floral charac- 
ters, but branched above and bearing several spikes: B. SPECIOSA 
(Meisn. Monogr. 66), AMPLEXICAULIS (Don. Prodr. 70) and 
OXYPHYLLA (Wall. Catal. n. 1715); and lastly two species of 
Asian mountains that are suffrutescent, bear graceful spikes of 
intensely red flowers, are hardy in England and highly orna- 
mental under cultivation in Kew Gardens: B. AFFINIS (Don. 
l. c.) and VACCINIIFOLIA (Wall. l. c. n. 1695). 
From Bistorta, the distribution of which is rather northern 
and subalpine, the transition to the almost subtropical genus 
TRACAULON is every way abrupt. No thoughtful and unbiased 
mind would be likely to regard the two groups of species as 
members of one and the same genus; and in the early history 
of the typical species they were associated with Fagopyrum or 
else Helxine rather than with Polygonum ; so even with Linn- 
æus at the first. 
