Punctuation

Q. Where does punctuation fall in the context of botanical varieties, which are treated with single quotation marks? I have been assiduously changing commas that are inside the final single quote, moving them outside: Excellent garden varieties include Ceanothus ‘dark star’, ‘Yankee Point’, and ‘Joyce Coulter’. But I’m now starting to have doubts.

A. Doubt no more. Please see CMOS 8.129, Horticultural cultivars: “Such names are enclosed in single quotation marks; any following punctuation is placed after the closing quotation mark. If the English name follows the Latin name, there is no intervening punctuation. For examples of this usage, consult any issue of the magazine Horticulture.”