Opposite, toothed, scented leaves. Flowers in whorls over the summer. Most preferring a damp soil and often having spreading habits, so appropriate siting is very important. Particularly in smaller gardens, growing in pots, trough or a container with a couple of holes in. A very important herb, found across the Mediterranean. At least over 1000 varieties are available. Interestingly the common name of spearmint, is maybe a corruption of sprire mint, referring to the flower spikes resembling a church spire.
A very complex genus, with much hybridization, but always a more-or-less minty scent to the leaves, which serves to deter insect (and probably mammalian) herbivores - human beings may be the only species to have adjusted their palate to enjoy plant-defence chemicals... This deterrence does not however extend to the flowers, which attract a very wide range of insects, including bees and butterflies: the more open individual flowers than in most genera of the Lamiaceae allow access by all-comers. Most species have a strong tendency to spread vegetatively so that steps should be taken to discourage them from getting 'over the garden fence'.