I asked my friend Lisa Thoerle about how to properly capitalize a natural hybrid. Here is her response: From the International Code of Nomenclature for algae, fungi, and plants (the ICN, Melbourne Code; and "algae, fungi, and plants" is not capitalized): H.3A.1. In named hybrids, the multiplication sign × belongs with the name or epithet but is not actually part of it, and its placement should reflect that relation. The exact amount of space, if any, between the multiplication sign and the initial letter of the name or epithet should depend on what best serves readability. Note 1. The multiplication sign × in a hybrid formula is always placed between, and separate from, the names of the parents. [L: Note that this is only for formulae] H.3A.2. If the multiplication sign is not available it should be approximated by the lower-case letter “x” (not italicized). Many journals demand a space preceding the specific-level epithet, following the "×." But either no space or one space may be used, and sometimes one space is more clear than no space, e.g., if the epithet begins with a vowel or one cannot use the multiplication sign rather than the letter "x." For capitalization, specific-level epithets of man-made hybrids are capitalized and the names do not follow the ICN rules for naming. Your example of Coelogyne Unchained Melody shows this clearly. For natural hybrids "where at least one parental taxon is known or can be postulated" (ICN H.3.2), things described under ICN rules, the name is not capitalized and follows the usual naming and orthographic conventions (but not all of the requirements for publication), with the addition of the "×." If you want the name for a man-made hybrid, consult the hybrid registry at Kew. If you want the scientific name for a hybrid that has been formally described, use TROPICOS, ipni, the Kew Monocot Checklist, or plantlist. Each has its own strengths and weaknesses. More information and prescriptions can be found in Appendix I, Names of Hybrids, in the ICN. Above, I included only the parts that seemed useful for this discussion. The ICN devotes pages to this matter. There's a whole code for cultivated plants: The International Code of Nomenclature for Cultivated Plants (http://www.actahort.org/chronica/pdf/sh_10.pdf). There might be some interesting stuff there.