44 Rhodora [Marcu 
Boiss. previously described; Stipa L. Sp. Pl. ed. 1, 78 (1753), valid because 
accompanied by a description in the Genera Plantarum ed. 5, no. 84 (1754).— 
The following are not valid: Egeria Neraud (Bot. Voy. Freycinet, p. 28 (1826), 
published without diagnosis or reference to a description previously made 
under another name; Acosmus Desv. mentioned incidentally as a synonym 
of the genus Aspicarpa Rich. by De Candolle (Prodr. 1, 583 [1824]); Zatar- 
hendi Forsk. Fl. Aeg. Arab., p. CXV (1775), based only on the enumeration 
of 3 species of the genus Ocimum without indication of characters. 
Art. 39. The date of a name or of a combination of names is that 
of their effective publication. In the absence of proof to the contrary, 
the date placed on the work containing the name or combination of 
names is regarded as correct. On and after January Ist, 1908, the 
date of publication of the latin diagnosis only can be taken into account 
in questions of priority. 
Examples. — Mentha joliicoma Opiz was distributed by its author in 1832, 
but the name dates from 1882 (published by Déséglise Menth. Op. in Bull. 
soc. étud. scient. Angers, 1881-1882, p. 210); Mentha bracteolata Op. Seznam, 
p. 65 (1852) without description, takes effect only from 1882, den it was 
published with a description (Déséglise 1. c., p. 211). There is some reason for 
supposing that the first volume of Adanson's Familles des Plantes was published 
in 1762, but in absence of certainty the date 1763 on the title-page is assumed 
to be correct. The different parts of Willdenow's Species Plantarum were 
published as follows: vol. I, 1798; vol. IT, 2, 1800; vol. III, 1, 1801; vol. III, 
2. 1803; vol. III, 3, 1804; vol. IV, 2, 1806; and not in the years 1797, 1799, 
1800, 1800, 1800 and 1805 respectively, as would appear from the title-page 
of the volumes: it is the earlier series of dates which takes effect. ^ lie 
third volume of the Prodromus florae hispanicae of Willkomm & Lange, 
the title-page of which bears the date 1880, was published in four parts, pp. 
1-240 in 1874, pp. 241-512 in 1877, pp. 513-736 in 1878, p. 737 to the actis 
1880, and it is these dates which take effect. ‘ 
Recommendations. Botanists will do well, in publishing, to conform to 
the following recommendations: 
VIII. Not to publish a name without clearly indicating whether it is 
the name of a family or a tribe, a genus or a section, a species or a variety; 
briefly, without expressing an opinion on the nature of the group to which 
they give the name. 
XIX. To avoid publishing or mentioning in their publications unpublished 
names which they do not accept, — if the. persons responsible for these 
names have not formally authorised their publication (see Rec. XIV, e). 
XX. When publishing new names in works written in a modern language 
(floras, catalogues etc.) to publish simultaneously the latin diagnoses which 
will make the names valid from the point of view of scientific nomenclature. . 
XXI. To give the etymology of new generic names and also of specific 
names when the meaning of the latter is not obvious. 
XXII. To indicate precisely the date of publication of their works and 
that of the placing on sale or the distribution of named and numbered plants 
when these are accompanied by printed diagnoses. In the case of a work 
appearing in parts, the last published sheet of a volume should indicate the 
precise dates at which the different fascicles or parts of the volume were 
published, as well as the number of pages in each. 
XXIII. When works are published in periodicals to require the editor 
to indicate on the separate copies the date (year and month) of publication 
and also the title of the periodical from which the work is extracted. 
XXIV. Separate copies should always bear the pagination of the periodical 
of which they form a part; if desired they may also bear a special pagination, 
