Asa Gray made clear the distinction between subgenus and section in the preface of the second edition of his Manual of Botany of the Northern United States (1856). He failed to distinguish between the two infrageneric ranks in the 1848 edition. In 1856, subgenera were published with the symbol § followed by the epithet in capitalized letters while the epithets at sectional rank appear following the symbol § with only the initial letter capitalized. This clarification does not change the nomenclature of the correct name for the subgenus to which the herbaceous-stemmed smilaxes of North America and also eastern Asia belong, and whose subgeneric name is Smilax subgenus Luiste Raf. (1840).