BOTANICAL NOMENCLATURE 



validated by mention of the included families; that of a family is 

 not validated by mention of the included genera ; that of a genus is 

 not validated by mention of the included species. E. g. the generic 

 name Ibidinm Salisbuiy (Trans. Hort. Soc. i, 291: 1812) was published 

 merely with the mention of four included species: as Salisbury sup- 

 plied no generic description, the publication of Ihidium was invalid. 



Art. 42. A name of a genus is not validly published unless it is ac- 

 companied (1) by a description of the genus, or (2) by the citation of 

 a previously and effectively published description of the genus under 

 another name, or (3) by a reference to a previously and effectively 

 published description of the genus as a subgenus, section or other sub- 

 division of a genus. 



An exception is made for the generic names published by Linnaeus 

 in Species Plantarum, ed. 1 (1753) and ed. 2 (1762-63), which are 

 treated as having been validly published on those dates (see Art. 20). 



Note. — In certain circumstances a plate witli analyses is accepted as equivalent 

 to a generic description (see Art. 43). 



Art. 43. The name of a monotypic new genus based on a new species 

 is validated (1) by the provision of a combined generic and specific de- 

 scription (descriptio generico-specifica) , (2) by the provision of a plate 

 with analj^ses showing essential characters; but this applies only to 

 plates and generic names published before January 1, 1908. 



Art. 44. The name of a species or of a subdivision of a species is 

 not validly published unless it is accompanied (1) by a description 

 of the group, or (2) by the citation of a previously and effectively 

 published description of the group under another name, or (3) by a 

 plate or figure w^th analyses showing essential characters; but this 

 applies only to plates or figures published before January 1, 1908. 



Art. 45. The date of a name or of an epithet is that of its valid 

 publication (see Art. 19, 36). For purposes of priority, however, only 

 legitimate names and epithets published in legitimate combinations 

 are taken into consideration* (see Art. 60). In the absence of proof to 

 the contrary, the date given in the work containing the name or epi- 

 thet must be regarded as correct. 



On and after January 1, 1935, only the date of publication of the 

 Latin diagnosis can be taken into account for recent plants except 

 Bacteria. 



For fossil plants, on and after January 1, 1912, the date is that of 

 the simultaneous publication of the description and figure (or, if 

 these are published at different dates, the later of the two dates). 



Botanists will do Avell in publishing to conform to the following 

 recommendations :■ — ■ 



XXI. Not to publish a new name without clearly indicating whether it is the 

 name of a family or a tribe, a genus or a section, a species or a variety; briefly, 

 without expressing an opinion as to the rank of the group to which the name is 

 given. 



Not to publish the name of a new group without indicating its type (see Eecom- 

 mendation IV). 



XXII. To avoid publishing or mentioning in their publications unpublished 

 names which they do not accept, especially if the persons responsible for these 

 names have not formally authorized their publication (see Recommendation XV 



85 



•A legitimate name or epithet is one that is strictly in accordance with the Rules. 



