In the scientific classification of species, the genus name is capitalized and the species name is not, but both names are italicized. The scientific naming conventions for varieties and cultivars are that the variety term is lower case and italicized and the cultivar term is not italicized, but the latter is capitalized and placed in single quotation marks. To complicate matters, a trademarked name is not part of the scientific name but is used in marketing. See outside link here.

When neighbors hear that our magnolia is a southern magnolia, they are skeptical about whether it will survive in the Philadelphia climate. There are several southern magnolias in the city, some of which are doing quite well. Most of these are in protected microclimates, e.g. a sunny southern exposure near a building that provides wind protection. Varieties (naturally occurring variants) cand cultivars (human selected and bred variants) may have features that enhance cold hardiness. More compact dense growth and shorter mature height are some of these features.