40 



Examples: X Salix capreola = Salix aurita x caprea; Digitalis lutea Ç x purpurea (J; 

 Digitalis lutea (J x purpurea Ç. 



Art. 32. Intergeneric hybrids (between species of different genera) or pre- 

 sumably such, are also designated by a formula, and, when it seems useful or necessary, 

 by a name. 



The formula consists of the names of the two parents, in alphabetical order. 

 The hybrid is associated with the one of the two genera which precedes the 

 other in alphabetical order. The name is preceded by the sign x. 



Example: x Ammophila baltica = Ammophila arenaria x Calamagrostis epigeios. 



Art. 33. Ternary hybrids, or those of a higher order, are designated like 

 ordinary hybrids by a formula and a name. 



Example: X Salix Straehleri = S. aurita x. cinerea x. repens or S. (aurita x. repensj 

 X cinerea. 



Art. 34. When there is reason to distinguish the different forms of a hybrid 

 (pleomorphic hybrids, combinations between different forms of collective species etc.) 

 the subdivisions are classed under the hybrid like the subdivisions of species under 

 a species. 



Examples: x Mentha villosa ß Lamarckii {== M. hngifolia x rotundifolid). The prepon- 

 derance of the characters of one or other parent may be indicated in the formulas in the following 

 manner: Mentha longifolia "^^ x rotundifolia, M. longifolia x <:^ rotundifolia, Cirsium super canum 

 X rivulare, etc. etc. The participation of a particular variety may also be indicated. Example- 

 Salix caprea x daphnoides var. pulchra. 



Recommendation. 



XVII. Half-breeds, or presumably such, may be designated by a name and a formula. 

 Names of half-breeds are intercalated among the subdivisions of a species preceded by the sign x. 

 In the formula the names of the parents are in alphabetical order. 



Section 4. The publication of names and the date of each name or 



combination of names. 



Art. 35. Publication is effected by the sale or public distribution of printed 

 matter or indelible autographs. 



Communication of new names at a public meeting, or the placing of names 

 in collections or gardens open to the public, do not constitute publication. 



Examples. — Effective publication without printed matter: Salvia oxyodon Webb and Heldr. 

 was published in July 1850 in an autograph catalogue and put on sale (Webb and Heldreich, Cata- 

 logus plantarum hispanicarum, etc. ab A. Blanco lectarum, Parisiis, Jul. 1850 in folio). — Non-effective 

 publication at a public meeting: Cusson announced his establishment of the genus Physospermum 

 in a memoir read at the Société des Sciences de Montpellier in 1773, and later in 1782 or 1783 at 

 the Société de Médecine de Paris, but its effective publication dates from 1787, in the Mémoires 

 de la Soc. Roy. de Medicine de Paris, vol. V, l'« partie. 



Art. 36. On and after January 1, 1908, the publication of names of new 

 groups of recent plants will be valid only when they are accompanied by a latin 

 diagnosis. 



