INTERNATIONAL RULES FOR BOTANICAL NOMENCLATURE 15 
er ee _ more species than the others, the name is Teserved for 
a ie: it. 
sa phcis The Helianthemum contained, according to 
Daal (in DO. Pied. i. "'266_ 284 [1824] ), 112 well-known species 
distributed in nine sections; several of these sections have since 
been raised to generic rank (Fwmana Spach, Tuberaria Spach), but 
the name Helianthemum has been kept for the divisions grouped 
round the section Euhelianthemum. The genus Convolvulus L. em 
ivi into tw 
a much larger number of eee In the same way, Salisbury tin ie 
Trans. Linn. Soc. vi. $17 [1802] ), in wea ge Erica vulgaris 
from the genus Erica, under the e Calluna, kept the name 
Erica for the large number of species le 1% ott. 
Article 46. When two or more groups of the same nature are 
united, the name of the oldest is retained. If the names are of the 
sam a a te, the author chooses, and his choice cannot be modified 
y ince authors 
Examples. Hooker f. and Thomson (Fl. Ind., p. 67 [1855] ) 
pulse the genera Wormia Rottb. and Capeliia Bl. ; eg gave the 
fect 1788, while Capellia dates from 1825. In case of union of 
the two genera Cardamine ~ Dentaria, which were founded at the 
same time by Linneus (Sp. Pl. ed. 1, pp. 653 and 654 [1753]; Gen. 
Pl. ed. 5, n. 36 Ds the Slee genus matt: be called Carda- 
mine, because me was chosen by ot Ape Crucif., 
p. 126 [1769}), hi wad the first to suggest the a 
Saree 
XXVI. Authors who have to choose peg two generic names 
should note the following ageneap ndatio 
two names of the e date, to pirate the one which was 
first accompanied by the Seacdpbion of a speci 
2. Of two names of the same date, both ea by 
descriptions of species, to prefer the one which, eh e author 
made his choice, inginies the Po arger number of spec 
cases uality from these oo ois of view, to — 
prefer the more coiett aad scoropsiats & nam 
ne . Bide several genera are united a gmialy or 
uffix (Stachys me Stachyotypus). vee prefixes or suffixes lapse 
ian the subdivisions are raised to generic rank. _ 
XXVIII. When several species are united as subspecies or 
varieties under a collective name, that subdivision that was first 
distinguished or described may retain its name (example: Sazifraga 
