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- A hybrid may get a normal botanical name; this will usually be the option of choice for naturally occurring hybrids.
- A hybrid may also be indicated by a formula listing the parents. Such a formula uses the multiplication sign "×" to link the parents.
- A hybrid name is indicated by a multiplication sign "×" placed before the name or epithet, as the case may be.
A hybrid name is a botanical name, and is treated like other botanical names, for most purposes. The multiplication sign is not part of the actual name and is to be disregarded for nomenclatural purposes such as synonymy, homonymy, etc. This means that, say, Drosera ×anglica for nomenclatural purposes is to be treated as Drosera anglica. A taxonomist could decide to use either form of this name: Drosera ×anglica to emphasize that it is a hybrid, Drosera anglica to emphasize that it is a species.
A hybrid name is unlike other botanical names in that it does not necessarily refer to a cohesive unit but applies to all progeny of the parents, no matter how much the variation. So, Magnolia ×soulangeana applies to all progeny from the cross Magnolia denudata × Magnolia liliiflora, and from the crosses of all their progeny, as well as from crosses of any of the progeny back to the parents. This covers quite a range in flower colour.
The multiplication sign should be put before the name in case of intergeneric hybrid and otherwise before the relevant epithet. Only when a multiplication sign is not available (e.g., on some typewriters), a small letter "x" may be used as a replacement. Examples:
- Dianthus ×allwoodii (the equivalent formula is Dianthus caryophyllus × Dianthus plumarius). This is an "interspecific hybrid" (a hybrid between two species in the same genus): the multiplication sign goes before the epithet.
- ×Heucherella tiarelloides (the equivalent formula is Heuchera sanguinea × Tiarella cordifolia). This is an "intergeneric hybrid" (a hybrid between two different genera): the multiplication sign is placed before the generic name. This generic name is a so-named "nothogeneric name" and is a condensed formula, formed from the generic names of the parents: e.g., ×Heucherella combines Heuchera and Tiarella).
Note that the name for a graft-chimaera uses an addition sign "+".
The provisions in the ICBN that deal with hybrid names are Art H.1 to H.12.