48 



is universally regarded as non-valid, or for any other motive either contestable or of 

 little import. (See also art. 57.) 



Examples. — This rule was broken by the change of Staphylea to Staphylis, Tamus to Thamnos, 

 Mentha to Minthe, Tillaea to Tillia, Vincetoxicum to Alexitoxicon\ and by the change of Orobanche 

 Rapum to O. sarothaninophyta, O. Columbariae to O. co lumbar ihaer ens, O. Artemisiae to 0. artemisi- 

 epiphyta. All these modifications (which are contrary to Art. 50) must be rejected. — The name 

 Diplomorpha Meissn. in Regensb. Denkschr. Ill, 289 (1841) must not be substituted for the generic 

 name Wickstroemia Endl. Prodr. fl. Norfolk., 47 (1833) because of the earlier homonyms Wi(c)k- 

 stroemia Schrad. Goett. gel. Anz., 710 (1821) and Wi(c)kstroemia Spreng, in Vet. Akad. Handl. 

 Stockh. 1821, 167, t. 3, for the former is merely a synonym of the genus Laplacea Kunth (1821) 

 and the latter of a subdivision of the genus Eupatorium L. (1753). 



Kecommeudations. See on the subject of homonyms recommendations Vô and XI V/ 

 which suggest that cases of this kind should be avoided for the future. 



Art. 51. Everyone should refuse to admit a name in the following cases: 



1. When the name is applied in the plant kingdom to a group which has 

 an earlier valid name. 



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 monstrosity. 



4. When the group which it designates embraces elements altogether in- 

 coherent, or when it becomes a permanent source of confusion or error. 



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



Examples. — 1°. Carelia Adans. (1763) is a name which was applied by its author to a genus 

 which had already received a valid name (Ageratum L. [1753]) {synonym)^ similarly Trichilia alata 

 N. E. Brown (in Kew Bull. 1896, 160) is a name which cannot be maintained because it is a 

 synonym of T. pterophylla C. DC. (in Bull. Herb. Boiss. II, 581 [1894]). — 2°. Tapeinanthus, a name 

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

 of the existence of an earlier and valid genus, Tapeinanthus Herb, among the Amaryllidaceae; 

 (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 

 Illtcstr. Bot. Himal. p. 200 (1835). — 4^ The genus Uropedium Lindl. was based on a monstrosity 

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

 characters from the two genera Cuscuta and Myrica (parasite and host) and must be dropped; and 

 the same applies to Lemairea De Vr. which is made up of elements taken from different families. 

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

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

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

 abandon the name altogether. 



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

 tribe, must be changed when it is taken from a genus which, by general consent, 

 does not belong to the group in question. 



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

 Portulacaceae, the name Portulacaceae would have to be changed. — Nees (in Hooker and Arnott, 

 Bat. Beechey's Voy. 237 [1836]) gave the name Tristegineae to a tribe of Gramineae, after the genus 

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

 from this tribe by Stapf (in Fl. Cap. VII, 313) and by Hackel (in Oesterr. bat. Zeitschr. LI, 464), 

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



