in case the usage symbol "^" was already present. The right-hand parenthesis, ")", 

 implies that the synonym is a valid name (that, usually, occurs only outside the 

 United States) by our contributor's view, but which, in a wider view, is the parent 

 taxon of the accepted name in the list. The symbol ")" does not replace ">". The 

 symbol "N" is used typologically to mean that the name of a synonym has been used 

 for a set of specimens (taxon) excluding the true type of the name. The symbol "N" 

 has also been used to separate paired names which are not considered taxonomic 

 synonyms by the consultants. Taxonomic symbols precede usage symbols where the 

 latter have been retained. 



The default prefix is an asterisk, when the relationship between a pair of names 

 is unspecified. Prefixes referring to types are generally lacking in the Gramineae, 

 the Compositae, and groups for which there is no consultant. 



Many names in the synonymy list, which are not differentiated specifically, are 

 valid names for extralimital taxa. These have been misapplied to US taxa, been 

 wrongly attributed to the United States among the source manuals , or been included 

 by mistake. 



Certain synonymy is implied, though unstated. Infraspecific names may lack 

 synonyms. Such trinomials are referable: first, to accepted identical trinomials of 

 a different rank; second, to the accepted type variety or subspecies of the parent 

 species; or third, to an accepted name of the same final epithet within the correct 

 species name for other synonym names of the parent species. 



For genera, the system of prefixes is less elaborate. A generic name is followed 

 by a synonym if it is illegitimate (prefixes "=" or "*") . Synonym genera that are 

 taxonomic segregates of other genera that have been conserved are depicted as less 

 than (<) the conserved genera. The sign "=" rather than 'W' is used for contypicity 

 of generic names. 



Accepted Infraspecific Taxa of Nonresident Taxa 



On the continent, absence of "distribution" shows that we REJECT THE TYPE VARIETY 

 of a species (for the U.S.), but accept certain infraspecific taxa. In "H", or the 

 "C" and "V" regions, absence of all the symbols "N" (native), "I" (introduced), or 

 ">c" (unknown) in the first position of "Habit" implies the same. 



Checklist Usage Notes 



Certain genera have been chosen over others. However, in some instances certain 

 acceptable taxa have never been recombined with names in the proper genus. In these 

 cases, the names have been accepted in the genus v^ere they are validly published. 

 Thus, for example, Dentaria has been sunk into Cardamine in the Cruci ferae except 

 for two varietal names. Similarly, Chamaesyce and Galarhoeus are considered as part 

 of Euphorbia by our consultant, Michael T. Huft, but certain taxa have published 

 names only in the former genera. Derek Burch, who has also corresponded with us, 

 considers the characteristics of Chamaesyce distinct enough to warrant generic 

 recognition. 



