[2] The specific epithet pulegioides highlights its similarity to another species within Lamiaceae, Mentha pulegium (pennyroyal).

It is rather similar to wild thyme (Thymus serpyllum) but it is larger, the leaves are wider and all the stems form flowering shoots.

The leaves are in opposite pairs with short stalks, and the linear ovate blades have tapering bases and untoothed margins.

The usually pink or mauve flowers form rounded umbels and each has a tube-like calyx and an irregular straight-tubed, hairy corolla.

Numerous cultivars have been selected, of which 'Aureus',[5] with lemon-scented gold leaves, and 'Bertram Anderson'[6] have both gained the Royal Horticultural Society's Award of Garden Merit.