The Lamiaceae (known as the Labiatae to those of us that like the traditional names) has around 3200 species and 200 genera. 

Despite being one of the larger families, the Lamiaceae is also one of the easier families to recognize, most of the time. First of all, its members tend to be smelly—not fragrant, smelly—but not always unpleasantly smelly. Think of mint, catnip, and thyme. In some cases, the odor can be detected easily; in others, the plants have to be bruised or crushed before the compounds involved are released in sufficient quantity for the human nose to detect them. Walking through or over the plant provides adequate damage for this purpose. Another character people seem to remember easily is Opposite leaves and square stems. WARNING: this combination occurs occasionally in some other families, so look for another character before placing a bet on your answer.

The other distinctive pair of features to look for is a strongly bilaterally symmetric corolla and four nutlets. Remember, the Boraginaceae, another family that produces four nutlets, has a radially symmetric corolla, so you need to look at both the corolla shape and the fruit.

The Lamiaceae is global in distribution, with a particularly high concentration occurring in the Mediterranean region. In general, species of the Lamiaceae tend to grow in open habitats, and are often associated with a Mediterranean climate. Many of the species in the maquis vegetation of the Mediterranean belong to the Lamiaceae.

Vegetatively, the Lamiaceae are herbs or sub-shrubs, with opposite and decussate leaves and square stems. There are no stipules. The plants almost always have numerous glandular hairs. It is these that release the aromatic compounds that our noses detect.

Both the calyx and the corolla are united, but it is the corolla that is always strongly bilaterally symmetric, having a distinct upper and lower lip, i.e., the flowers are said to be bilabiate, a term that means 'two-lipped'. It is this characteristic that is the basis of the traditional name, Labiatae.

Although most flowers have an androecium and gynoecium, the stamens are often reduced or modified and sterile, making the flowers functionally pistillate. Such flowers are often smaller and paler than the bisexual flowers. There are 2 or 4 stamens, which may or may not be of the same length. The gynoecium consists of a single, bicarpellate pistil with a superior ovary and, generally, a two-forked style. The ovary of the Lamiaceae resembles that of the Boraginaceae m consisting of two locules, each with two ovules. As the ovary matures, the ovary wall coheres to the ovule walls so, at maturity, the fruit consists of four nutlets.

There are lots of specialized pollination mechanisms in the Lamiaceae. In some, the stamens are held within the enfolding lobes of the corolla until an insect lands on the corolla. At that point, the stamens are suddenly released and the pollen bursts out of the anthers, all over the insect. In others, the pollinator pushes on a connective which effectively prevents access to the nectar; but, in doing so, the other end of the staminal arm pivots and dumps pollen on the insect's back.

The smells associated with the Lamiaceae are from terpenes. Many of these compounds are effective in suppressing the growth of other species. Some have been shown to suppress the germination of grasses in the Californian chaparral.  Chemical warfare is normal among plants.