42 Rhodora [Marcu 
The formula consists of the names of the two parents, in alphabeti- 
cal 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. 
Examples: 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. 
Examples: X Salix Straehleri — S. aurita X cinerea X repens or S. (au- 
rita X repens) 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 B Lamarckii (= M. longifolia X rotundifolia). 
The preponderance 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 supercanum 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, Catalogus plantarum hispanicarum, 
elc. ab A. Blanco lectarum, Parisiis, Jul. 1850 in folio).— Non-effective publi- 
cation at a publie 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 
Médecine de Paris, vol. V, lre partie. 
