April 4, 1919] 



SCIENCE 



335 



(Ait. Hort. Kew. 2: 360. 1789) is Chelone 

 Pentstemon (L. Sp. PL 612. 1753; ed. 2. 850. 

 1763) because the later is cited as a synonym 

 under one of the species of Pentstemon. 



Article 6. If a genus, when originally pub- 

 lished, includes more than one species, and no 

 species is definitely designated as type, nor in- 

 dicated according to Article 5, the choice of 

 the type should accord with the following 

 principles : 



(o) Species inquirendae or species doubt- 

 fully referred to the genus, or mentioned as 

 in any way exceptional are to be eccluded from 

 consideration in selecting the type. 



(6) Genera of the first edition of Linnseus's 

 " Species Plantarum " (1753) are usually typi- 

 fied through the citations given in the fifth 

 edition of his "Genera Plantarum" (1754) 

 except when inconsistent with the preceding 

 articles. 



Example.— Arundo (L. Sp. PI. 81. 1753) 

 is typified by A. Donax since this is the species 

 figured by Scheuchzer in the plate cited by 

 Linnaeus (Gen. PI. 35. 1754). 



(c) Species which definitely disagree with 

 the generic description (provided others agree), 

 or which possess characters stated in the 

 generic description as rare or unusual, are to 

 be excluded from consideration in selecting 

 the type. 



n. RECOMMENDATIONS 



Article 7. In the future it is recommended 

 that authors of generic names definitely desig- 

 nate the tjrpe species ; and that in the selection 

 of types of genera previously published, but of 

 which the type would not be indicated by the 

 preceding articles, the following points be 

 taken into consideration : 



(a) The type species should usually be the 

 species or one of the species which the author 

 had chiefly in mind. This is often indicated by 



1. A closer agreement with the generic de- 

 scription. 



2. Certain species being figured (in the same 

 work). 



3. The si)ecific name, such as vulgaris, com- 

 munis, medicinalis or officinalis. 



(b) The type apecies should usually be the 

 one best known to the author. It may be as- 



sumed that an indigenous species (from the 

 standpoint of the author), or an economic 

 species, or one grown in a botanical garden 

 and examined by the author, would usually 

 represent an author's idea of a genus. 



(c) In Linnsean genera the type should 

 usually be chosen from those species included 

 in the first technical use of the genus in pre- 

 Linnfean literature. 



Example. — The type species of Andropogon 

 L. should be chosen from the two species in- 

 cluded by Linnasus in the first use of the name 

 (L. Fl. Leyd. 1740). 



(d) The types of genera adopted through 

 citations of non-binomial literature (with or 

 without change of name) should usually be 

 selected from those of the original species 

 which received names in the first binomial pub- 

 lication. 



Example. — Cypripedium (L. Sp. PI. 951) is 

 typified by C. Calceolus. Under Cypripedium 

 (Gen. PI. 408. 1754) Linnaeus cites Calceolus 

 Toum. 249. Tournefort mentions 5 species, 

 one of which is cited under Cypripedium Cal- 

 ceolus by Linnaeus. 



(e) The preceding conditions having been 

 met, preference should be shown for a species 

 which will retain the generic name in its most 

 widely used sense, or for one which belongs to 

 a division of the genus containing a larger 

 number of species, or, especially in Linnaean 

 genera, for the historically oldest sipecies. 



Example. — Phalaris L. is typified by P. 

 canariensis because it is the only one of the 

 5 Lirmssan species known to the older writers 

 (such as Bauhin) by the name of Phalaris, so 

 far as shown by tihe synonyms given by Lin- 

 naeus. 



(/) Among species equally eligible, the pref- 

 erence should be given to the first known to 

 have been designated as the type. 



ig) If it is impossible to select a type under 

 the conditions mentioned above the first of 

 equally eligible species should be chosen. 



PERMANENT COMMITTEE ON NOMENCL.\TURE 



1. It is recommended that the present com- 

 mittee be enlarged to 9 members and be made 

 a standing committee on Botanical Nomencla- 



