211 49 



Art. 51. Every one sliould refuse to admit a naine in tlie following cases: 



1. When the naine is applied in tiie plant kingdoni to a group whicli lias 

 an earlier valid nanie. 



2. When it duplicates the name of a class, order, family or genus, or a sub- 

 division or species of the same genus, or a subdivision of the same species. 



3. When it is based on a nionsfrosity. 



4. WHien the group which it désignâtes embraces éléments altogether in- 

 cohérent, or when it becomes a i)ermanent source of confusion or error. 



fi. When it is contrary to the rules of sections 4 and 6. 



Examples. — 1". Cnrelia Adans. (1703) is a name wliich was applied by its author to a ]E;enus 

 wliicli had already received a valid name {Ageratum L. [1753]) {syitonym)\ similarl}- Trtchilia atata 

 N. E. Brown (in Ä^w Bull. [18it6] p. 160) is a name which cannot be maintained becavise it is a 

 synonym of T. pterophylla C. DC. (in Bull. Herb. Bons. 11, 581 [1894]). — 2°. Tapeinanthns, a name 

 giveii by Boissier to a genus of Labiatae was replaced by Thuspeinanta by Th. Durand, because of 

 the existence of an earlier and valid genus, Tapeinanthns Herb, among the Amaryllidaeeae 

 (homonym). Similarly Astragalus rhizanthus Boiss. (Diagn. PI. Or. ser. 1, II, 83 [1843]) was renamed 

 A. cariensis Boiss. because of the existence of an earlier valid homonym, Astragalus rhizanthus Royle 

 Illustr. Bot. Himal. p. 200 (1835). — 4°. The genus Uropedium Lindl. was hased on a monstrosity 

 which is now referred to Phragmopedilum caudatum Rolfe. — 5°. The genus Schrebera L. dérives its 

 cliaracters from the two gênera Cuscuta and Myrica (parasite and host) and must be dropped; and 

 the same applies to Lemairca De Vr. which is made up of éléments taken froni différent familles. 

 Linnaeus described under the name of Rosa villosa a plant which has been referred to several diffé- 

 rent species and of which certain identification seems impossible; to avoid the confusion which results 

 from tlie use of the name Rosa villosa, it is préférable in this case, as in other analogous cases, to 

 abandon the name altogether. 



Art. 52. Tiie name of an order, suborder, family or subfamily, tribe or sub- 

 tribe, must be ciianged when it is taken from a genus which, by gênerai consent, 

 does not belong to the group in question. 



Examples. — If it were to be shown that the genus Portulaea does not belong to the family 

 Portulacaceae, the name Portulacaceae would liave to be changed. — Nees (in Hooker and .Vrnott, 

 Bot. Beechey'i Voy. p. 237 [1836]) gave the name Tristegineac to a tribe of Gramineae, after the genus 

 Tristegis Nees (a synonym of the genus Melinis Beauv.). But Melinis (Tnstegis) having been excluded 

 from this tribe by Stapf (in /"/. Cap. VII. 313) and by Hackel (in Oesterr. bot. Zeitschr. LI, 464), 

 these authors have adopted the name Arundinelleae from the genus Arimdinella. 



Art. 53. When a subgenus, a section or a subsection, passes as such into 

 another genus, the name must be changed if there is already, in that genus, a valid 

 group of the same rank, under the same name. 



When a species is moved from one genus into another, its specific epithet 

 nuist be changed if it is already borne by a valid species of that genus. Similarly 

 when a subspecies, a variety, or some other subdivision of a species is placed under 

 another species. its name must be changed if borne already by a valid form of like 

 rank in that species. 



Examples. — Spartium biflorum Desf. (1798—1800) when transferred by Si)acli in 1849 into 

 the genus Cytisus could not be called Cytisns biflorus, but was renamed Cytisus Fontanesii, because 

 of the préviens existence of a valid species Cytis7is biflorus L'Hérit. (1789). The earliest synonym 

 of Calochortus Xultallii Torr, et (jray (in Pacific Rail. Rep. II, 124 [1855—1856]) is Fritillaria alba 



