196 



America as an introduced plant. Curtiss' collections in Florida 

 (Nos. 3690 and 5973) well represent the American plant, as do 

 the similar ones of Jenman from Guiana. Parkeria is one of 

 five generic names which have been independently proposed 

 for this group of plants and was based on Parker's original collec- 

 tion in Guiana, a duplicate sheet of which appears in the herba- 

 rium of Columbia University. 



PoLYPODiUM GLYCYRRHiz.A. D. C. Eaton. Am. Jour. Sci. II. 



22: 138. 1856 



This properly takes the place oi P. falcatuuiY^€i\o^^, 1854, 

 (not P. falcatum Linn. f. 1781) and of P. occidentale Maxon, 

 1904, the latter taken up from a still earlier varietal name of 

 Hooker. 



The abandonment of the validity of varietal names * was the 

 principal compromise on the part of the adherents of the Ameri- 

 can code at the Vienna Congress. The above nomenclature is 

 therefore in accord with both the Vienna and the American 

 codes, and is based on the correct principle that species are the 

 units of classification. 



Paltonium laxceolatum (L.) Presl, Epim. Bot. 156. 185 1, 

 appears to be the proper name for Pteris lanccolata L. {Tacnitis 

 lanccolata Kaulf.), for which we proposed Blume's subgeneric 

 name Clieilograuime in 1900. 



Pteris multifida Poir. Encyc. Bot. 5: 714. 1804 

 The above name should be used for the plant commonly 

 called Ptens serndata Linn. f. (1781). The earlier Pteris serrii- 

 lata Forsk. (1775) renders Linnaeus' name untenable. In this 

 case there is an even stronger reason : in reducing P. serndata 

 Linn. f. to synonymy under P. imdtijida, Mr. Christensen con- 

 tinues an error most of us have followed without actually looking 

 up the type locality of Linnaeus' plant. As a matter of fact Pteris 

 serndata is not only not a synonym of Pteris midtifida at all ; it 



*This principle was adopted in America by a small majority in 1893-4 and in 

 practice has worked havoc with many otherwise valid specific names. Probably two 

 thirds of the opposition to the Madison modification of the Rochester rules arose 

 from the adoption of this one principle. 



