18 INTERNATIONAL RULES FOR BOTANICAL NOMENCLATURE 
Section 7. On Names raat aRE To BE ResEctED, CHANGED, OR 
Mopiriep. 
Article 50. eee a is authorized to reject, change, or modify 
a name (or combination of names) because it is badly chosen, or 
Baiccsble, or saitlioe is preferable or better known, or because of 
the existence of an earlier homonym which is universally regarded 
as non-valid, or for any other motive either contestable or of little 
import. (See also Article 57. 
Examples.—This rule was broken by the change of Staphylea to 
Staphylis, Tamus to Thamnos, Mentha to Minthe, Tillea to Tillia, 
Vincetoxicum to Alexitowicon; and by the change of Orobanche 
‘apum to 0. sarothamnophyta, O. Columbarie to O. columbariharens, 
O. Artemisia to O. artemtsiepiphyta. All thes odific Ee 
(which are contrary to ie 50) must be rejected.—The nam 
Diplomorpha Meissn. in Regensb, Denkschr. iii. 289 (1841) must it 
be pabbeiiated for the TO name Wickstremia fas eg ti fi. 
re p. 47 (1838), because . ee earlier hom (e)ke- 
chrad. Goett. yel. Anz., p. tae are Dulaskuinasea 
Seen in Vet. Akad. Handl. ae TT , for the 
former is merely a synonym of the genus aes Kunth (1821), 
and the latter of a subdivision of the genus Eupatorium L. (1758). 
enes MMENDATIONS. See on the subject of homonyms Recommen- 
dations V.b and XIV.f, which suggest that cases of this kind 
should be avoided for the future 
Article 51. Every one should refuse to admit a name in the 
following cases :— 
- 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 eee os or : epenae of the same genus, or a sub- 
division of the same speci 
. ity. 
4. When the group which ait aie embraces elements 
yr bee incoherent, or when it becomes anent source of 
rror. 
5. When it is contrary to the rules of Section 
xamples. 1. Carelia eran ae is a ane which was 
applied by its author to a “spi ad already received a valid 
name (Ageratum L. [1758] ) iY ynon vm) similarly Trichilia alata N, 
EK. Brown (in Kew Bull. [1896] p. 160) i 
maintained because it is a sendey ih m of 7. pterophylla C. DC. (in 
Bull, Herb. Boiss. ii. 681 [ [1894] ).—2. Tapeinanthus, a name given 
imilarly 
Astragalus + gegiettre ore _ (Diagn. Pl. Or. ser. 1, ii. 88 r1843)) 
3 iss. because of the existence of an earlier 
valid homonym, here iniibieg rhizanthus Royle =. Bot. Himal. 
P. 200 (1835).—4. The genus Uropedium Lindl. was based on a 
monstrosity which is now referred to Para piopsdiiein caudatum 
