22 LEAFLETS. 
The characters of this genus are well brought out, though 
under the subgeneric name Kchinocaulon, by Meisner, DC., 
Prodr. xiv. 131. Hasskarl appears to have made more than one 
attempt to obtain recognition for the group as a genus a little 
later than the date of Rafinesque’s publication of the same 
opinion. 
Only three species of TRACAULON have been credited to the 
United States; two of which are correctly presented by Mr, 
Small in his admirable book; but his 7. Beyrichianum is 
doubtless a misapprehension. The real 7. Beyriehianum is 
Brazilian and the plant of our southern borders fails in impor- 
tant points to answer the description ofit. It is P, multangulare, 
H. & A. Comp. to Bot. Mag. ii. 62, and should be called T. MULT- 
ANGULARE. 
Next of kin to our two familiar species of the Eastern and 
Southern United States are three North Asian which in their 
earlier history were confused with ours in nomenclature. They 
are T. SIBIRICUM— P. sagittatum Sibiricum, Meisn., T. SIEBOLDII 
(Meisn.) founded on P. sagittatum Thunb. and T. THUNBERGII 
(Sieb. & Zucc.) based on P, arifolium Thunb. Yet a fourth 
Japanese species is T. HASTATO-TRILOBUM (Meisn.), and even 
antipodal Australia and New Zealand have one which was at 
first confused with our T. arifolium. This is "D strRiaosum 
(R. Br.) 
I subjoin a further list, far from complete, of TRACAULON 
species of various parts of the world, indicating where they were 
published under Polygonum: T. MEISNERIANUM (Ch. & Schl 
Linnea. iii. 40), RUBRICAULE and sTELLIGERUM (Oh. Linnea. 
viii. 130, 131), MURIcATUM (Meisn. Monogr. 74), pERFOLIATUM 
(Linn. Sp. 2 ed. 521), PEDUNCULARE (Wall. Catal. n. 1718), 
PRETERMISSUM (Hook. f. Brit. Ind. v. 47), HISPIDULUM and 
TETRAGONUM (Blume, Bijdr. 535), Maackianum (Regel, Fl. 
Ussur. 127). 
More easily confused with Polygonum, and somewhat similar 
in aspect to such plants as P. zenue, is a small group of Califor- 
nian annuals which the late Mr. Watson segregated under the 
subgeneric name of Duravia. But the characters of solitary 
