General:
Perennial herb from a stout taproot, white-woolly; stems ascending, 30-100 cm long, 4-angled, generally several; thyme-scented, cultivated for tea, flavouring.

Leaves:
Opposite, round to broadly egg-shaped, 2-5.5 cm long, about as wide, bases lobed to round, tips blunt, green and wrinkled above, white-woolly below, margins blunt-toothed; lower long-, upper short-stalked; uppermost leaves not much reduced.

Flowers:
Inflorescence of broad, many-flowered axillary clusters; corollas tubular, whitish, 8-15 mm long, slightly exserted from calyces, lips 2, about equal, the upper lip erect and narrowly 2-lobed, the lower lip spreading with broadly rounded central lobe; calyces star-shaped with ring of long hairs in throat, soft-hairy, the tube 4-5 mm long, the teeth 10, narrow, eventually widely spreading, sometimes unequal, tips spine-hooked.

Fruits:
Nutlets, 4 clustered together, egg-shaped, smooth.

Source:  The Illustrated Flora of British Columbia

If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

Illustration Source:  The Illustrated Flora of British Columbia