The name of a nothospecies of which the postulated or known parent species belong to different genera is a combination of a nothogeneric name with a nothospecific epithet.
×Heucherella tiarelloides (Lemoine & É. Lemoine) H. R. Wehrh. is considered to have originated from the cross between a garden hybrid of Heuchera L. and Tiarella cordifolia L. (see Stearn in Bot. Mag. 165: ad t. 31. 1948). Its basionym, Heuchera ×tiarelloides Lemoine & É. Lemoine (1912), is therefore incorrect.
The final epithet in the name of an infraspecific nothotaxon of which the postulated or known parental taxa are assigned to different species may be placed subordinate to the name of a nothospecies (but see Rec. H.10B).
Mentha ×piperita L. nothosubsp. piperita (M. aquatica L. × M. spicata L. subsp. spicata); M. ×piperita nothosubsp. pyramidalis (Ten.) Harley (in Kew Bull. 37: 604. 1983) (M. aquatica L. × M. spicata subsp. tomentosa (Briq.) Harley).
