Skullcaps are identified by the distinctive shield or helmet-shaped projection on the calyx that gives the genus its common name, derived from the Latin scutella, meaning a small dish or saucer. The genus spans a wide range of habits and habitats, with species suited to moist marshy margins, dry slopes, and everything in between. Most produce blue or blue-purple two-lipped flowers on square four-angled stems, and the majority are avoided by deer and rabbits because the foliage carries a pronounced bitter taste.

For gardeners, the most useful cultivated forms prefer full to partial sun in fertile, moist soil and do particularly well near ponds or in boggy margins. Drought-tolerant species like S. incana widen the genus's usefulness considerably, extending its reach into drier garden situations where most mint-family plants struggle. The plants spread by both rhizomes and seed, and the genus is remarkably free of serious insect and disease problems across its range from zones 3 through 9.