Numbers refer to page numbers. Infrageneric epithets have been entered directly under the generic name to which they belong, preceded by the indication of their rank (subg., sect., etc.). Infraspecific epithets have been entered under the specific name to which they belong, preceded by the indication of their rank (subsp., var., forma, etc.). Synonyms have been printed in italics. Page numbers in bold type denote main treatment; page numbers with an asterisk refer to a drawing, those with + denote a map.