Bergamot mint is a generally erect glabrous perennial growing to about 3' tall.  There is considerable disagreement or lack of consistency regarding the actual taxonomy of this species.  The Jepson Manual lists M. citrata as a synonym for M. Xpiperita, which is generally recognized as a hybrid of M. spicata (spearmint) and M. aquatica (water mint).  The X in the name stands for a hybrid species.  Munz's Flora of Southern California has piperita as a pure species, but does not include citrata.   L.H. Bailey's Manual of Cultivated Plants lists both piperita and citrata as pure species, as does Abrams' Illustrated Flora of the Pacific States.   Both of these older sources may just not have recognized that piperita was a hybrid species. The USDA Plants Database lists both Mentha citrata and M. piperita ssp. citrata as synonyms of M. aquatica.  Although the taxonomy is a mess, Xpiperita and citrata are obviously very closely related, but since there do seem to be differences between them, it seems to me to make the most sense to treat this taxon as a form, variety or subspecies of Xpiperita (peppermint).  And since I am treating it separately, it makes sense to call it by its own name.  The leaves are petioled and at least when young are ovate to suborbicular, and quite obtuse.  Later the plant's upper leaves do tend to be somewhat more lanceolate and almost acute-tipped.  The leaves are also shallowly serrate, a feature that again becomes more pronounced with age. The stems are often purplish (see the last picture), but this coloration appears to be reduced at anthesis. This mint produces whorls of rose-purple to white flowers at narrowly-spaced nodes in thick dense terminal heads or spikes, and sometimes (but not always) also in the upper leaf axils.  It grows in moist ground or other wet places like stream edges or drying streambeds, blooming from July to November, and is naturalized from Europe.

Click here for Latin name derivations: 1) Mentha   2) Xpiperita  3) citrata.
Pronunciation: MEN-tha pi-per-EYE-ta si-TRAY-ta.
Click here for Botanical Term Meanings.