1919] REHDER, NEW SPECIES, VARIETIES AND COMBINATIONS 49 



lated individuals showing slight variations but possessing the chief charac- 

 ters of the form in question. This is probably the idea underlying the rule 

 that Latin names like *' nanus, fastigiatus " are allowed, while proper Latin 

 names are proscribed, because the framers of that rule, though not clearly 

 stating it, apparently considered these Latin names to be group names. 



Horticulturists therefore should use names differing in form from botani- 

 cal names, if they desire to have the name stand for exactly the plant they 

 intend to name. This agrees with the way j)lant breeders generally look on 

 the named forms they distribute and the practice is well adapted for the 

 purpose it serves and should not be interfered with. A horticultural name 

 lapses when the plant disappears from cultivation, while a botanical name 

 remains still valid in such a case and should be used again, if at any time a 

 form appears answering to the description of the original form. 



A name like Thuja occidentalis L aurea Nicholson may be applied to dif- 

 ferent yellow-leaved forms differing in the shade of yellow and perhaps 

 slightly in other characters, but a name like '' Meehan's Golden '' stands 

 for an individual form and for Its vegetative progeny; if this plant had been 

 named " Meehanii " one would be justified in treating it as a botanical 

 name and make it a synonym of T, occidentalis aurca^ or if that latter name 

 did not exist, make it the t^T>e of a group of yellow-leaved forms in which 

 it would lose its individuality. 



In some instances names of new horticultural forms have been published 

 consisting of two not connected Latin words, e. g. Chamaccijparis pisifera 

 var. plumosa aurea; this name stands for a form which is different from C. 

 pisifera plumosa and also from C. pisifera aurea. According to the rules of 

 botanical nomenclature a varietal name can be used only once under the 

 same species, while according to the rules of horticultural nomenclature 

 varietal names consisting of two or three words are allowed, though one is 

 probably correct in assuming that this rule really is Intended for names in 

 the vulgar tongue like " Madame Casimir Perler " or " Mrs. Pollock." If 

 w^e consider " plumosa aurea " a horticultural name. It can he used, but may 

 be -^Titten C pisifera plumosa aurea or C. pisifera "plumosa aurea " to 

 bring out the fact by the difference in type or by the qviotatlon marks that 

 the varietal name is not a part of the botanical name. If, however, " plu- 

 mosa aurea " is considered a botanical name, it must be changed, as It Is 

 contrary to the rules of botanical nomenclature, and a new name chosen, 

 consisting of a single word. It seems rather doubtful if It Is advisable to 

 coin new names for all cases where the name of a horticultural variety con- 

 sists of two or more words, and therefore, it Is probably better to leave and 

 use these names as they are, indicating only by the manner of ^^Titing and 

 quoting them, that they are not part of the botanical name and that the 

 whole name is not a combination in the nomenclatorial sense of the term. 

 Of the modifications concerning hybrids, the most important adopted by 

 the Horticultural Congress is contained in art. xiii. which reads: " Bigeneric 

 hybrids are also designated by a name and a formula. The generic name is 

 formed by the combination of the generic names of the parents. . • . 



