REVISION OF RUMEX. 75 
species recognized by me as occurring within our flora, 
eleven were characterized and named by Linneeus in the first 
edition of the Species Plantarum, and only five have been 
named by American botanists. As a rule, though 
puzzling to the novice, they are well marked, and I have 
been able to complete my revision of the principal American 
material without seeing the necessity of designating any 
forms as new, though it may be that those mentioned 
under salicifolius and crispus will ultimately demand recog- 
nition as separate species. As illustrating the degree to 
which one so disposed may multiply species, it may be 
stated that in a very limited local flora (that of Lyon, 
France), Gandoger in 1875 (fide Just, ii1, 685, ) described 
sixteen new species, which other botanists are disposed to 
consider only forms or hybrids of familiar species. The 
practice of applying new specific names to known hybrids 
is also calculated to increase unwarrantably the enumerated 
speciesof a given region, since some of the docks and sor- 
rels are known to hybridize quite freely. 
One of our twenty-one species is merely a ballast intro- 
duction ; seven others are Old World weeds ; two ( Acetosa 
and salicifolius) are apparently arctic-alpines of wide dis- 
tribution, while the other eleven belong essentially to the 
North American flora. 
Among the more important references to the specific 
delimitation of docks, aside from the monographs already 
referred to, should be noted: — Trimen, various papers in 
Journal of Botany, about 1873; Haussknecht, Oesterr. 
Bot. Zeitschrift, 1876, xxvi. (Just, 1876, part 2, 963 and 
988 ), and Mittheil. Geogr. Ges. f. Thiringen, Jena, 1884, iii. 
56-79 (Just, xii. part 2, 592), — where many hybrids are 
named; Murbeck, Beitr. z. Kenntn. der Flora von Siidbos- 
nien u. d. Hercegovina, in Lunds Universitets Aarsskrift, 
1891, xxvii.; and Rechinger, Oesterr. Bot. Zeitschr., 1891, 
400. 
~The chief biological interest in the genus comes from 
the protective acidity of the sorrels and some docks and the 
