Epithet: All words in a combination other than the generic name and rank-denoting terms, e.g. Rebutia heliosa (specific epithet), Rebutia neocumingii subsp. pulquinensis (specific epithet and infraspecific epithet), Astrophytum subgen. Stigmatodactylus (subdivisional epithet). Specific and infraspecific epithets are usually written with an initial lower-case letter, although this is not mandatory. Subdivisional epithets must be written with an initial capital letter.