47 



Becommendations. Authors who make the changes discussed in article 49 should note 

 the following recommendations in order to avoid a change of name in case of a change of rank 



XXIX. 1". When a sub-tribe becomes a tribe, when a tribe becomes a subfamily, when 

 a subfamily becomes a family, etc., or when the inverse changes occur, do not alter the root of a 

 name but only the termination (-mae, -eae, -oideae, -aceae, -ineae, -ales, etc.), unless, in the new position, 

 one of the obstacles indicated in the articles of section 7, supervenes, or the new designation becomes 

 a source of error, or there is some other serious reason against it. 



2 ". When a section or a subgenus becomes a genus, or the inverse changes take place, 

 retain the old names, unless this results in two genera of plants having the same name, or the 

 existence of two subdivisions of the same name in the same genus, or one of the obstacles indicated 

 in the articles of section 7 supervenes. 



3 °. When a subdivision of a species becomes a species or the inverse change occurs, retain 

 the original epithets, unless this results in two species bearing the same name in the same genus, or 

 two subdivisions bearing the same name in the same species, or unless any of the obstacles indicated 

 in section 7 supervenes. 



Art. 49^'^ Among Fungi with a pleomorphic life-cycle the different successive 

 states of the same species (anamorphoses, status) can bear only one generic and 

 specific name (binomial) that is the earliest which has been given, starting from Fries, 

 Systema, or Persoon, Synopsis, to the state containing the form which it has been 

 agreed to call the perfect form, provided that the name is otherwise in conformity 

 with the rules. The perfect state is that which ends in the ascus stage in the Asco- 

 mycetes, in the basidium in the Basidiomycetes, in the teleutospore or its equivalent 

 in the Uredinales, and in the spore in the Ustilaginales. 



Generic and specific names given to other states have only a temporary 

 value. They cannot replace a generic name already existing and applying to one or 

 more species, any one of which contains the "perfect" form. 



The nomenclature of Fungi which have not a pleomorphic life-cycle follows 

 the ordinary rules. 



Examples. — The names Aecidium Pers., Caeoma Link and Uredo Pers. designate different 

 states (aecidiosporic with or without pseudoperidium, uredosporic) in the group Uredinales. The generic 

 name Melampsora Cast. \Obs. II, 18 (1843)], applied to a genus which is defined by means of the 

 teleutospores, cannot therefore be replaced by the name Uredo Pers. [in Römer Neu. Mag. I, 93 

 (1794)] since the name Uredo is already used to designate a state. — Among the Dothideaceae 

 (Ascomycetes) a species of the genus Phyllachora Nitschke, P. Trifolii (Pers.) Fuck. Syntb. 217 

 1869—70) has an older synonym, Polythrincium Trifolii G. Kunze Myk. Heft. I, 13, t. 1 f. 8 (1817) 

 based on the conidial state of this species. The name Polythrincium cannot displace that of Phyllachora 

 because it represents an inferior state. — The name Phoma Fries emend. Desm. has been given to a 

 group of Fungi Imperfecti (Deuteromycetes), several members of which have been recognised as the 

 spermogonial state of species of the genus Diaporthe (Valsaceae, Ascomycetes): thus Phoma Ailantht 

 Sacc. belongs to Diaporthe Ailanthi Sacc, Phoma alnea (Nitschke) Sacc. to Diaporthe alnea Fuck., 

 Phoma detrusa (Fries) Fuck, to Diaporthe detrtisa Sacc. etc. But the perfect state of many species 

 of the 'genus' Phoma is not known and in some cases probably does not exist. Hence the practical 

 necessity for retaining the name Phoma to designate the group of Fungi Imperfecti in question. 



Section 7. On names that are to be rejceted, changed or modified. 

 Art. 50. No one is authorised to reject, change or modify a name (or com- 

 bination of names) because it is badly chosen, or disagreeable, or another is pre- 

 ferable or better known, or because of the existence of an earlier homonym which 



