General:
Annual herb from a taproot; stems erect, 20-80 cm tall, coarse, branched when well developed, 4-angled, bristly-hairy, including red-tipped glandular-hairs, below nodes.

Leaves:
Opposite, egg-shaped to lanceolate, 3-10 cm long, 1-5 cm wide, coarsely blunt-toothed, tips pointed, bases rounded or wedge-shaped, stiff-hairy; stalked.

Flowers:
Inflorescence of several dense axillary flower clusters, subtended by upper leaves; corollas tubular, purple or pink or white with dark markings, 15-23 mm long, the upper lip arched and entire, the lower 3-lobed, spreading, the middle lobe flat, entire, often nearly as wide as long, bearing 2 nipple-like protuberences on the upper side near base, its network of dark markings restricted to the base, not reaching the margins; calyces about 1 cm long at flowering, somewhat larger in fruit, the erect spine-tipped teeth about equaling tube, the tube strongly 5-ribbed, hairy within; stamens 4, anthers hairy.

Fruits:
Nutlets, 4 clustered together, egg-shaped, 3-4 mm long, smooth.

Notes:
Galeopsis tetrahit originated from G. pubescens Bess. and G. speciosa Mill. by hybridization and polyploidy. The species may have arisen more than once, and may owe some of its variability to various origins.

Source:  The Illustrated Flora of British Columbia