- Name also: Sweet Gale, Bog-myrtle
- Family: Bog Myrtle Family – Myricaceae
- Growing form and height: Small, erect shrub. 0.5–1 m (1.5–3.5 ft.).
- Flower: Small, lacking perianth. Male and female flowers usually in separate inflorescences and on separate individuals. Male inflorescence a yellowish-green, spike-like catkin. Female inflorescence a yellowish-brown spike. Stigmas purple red.
- Leaves: Narrowly obovate, serrate (with saw-like teeth) at the top, greyish-green with yellow glands, hairy beneath. Margins turned downwards.
- Buds: Small, brown, cone-shaped.
- Fruit: Dry drupe, borne in cone-like groups.
- Habitat: Shores of lakes and the sea; rarely bogs, eutrophic and mesotrophic fens.
- Flowering time: April–May. Flowers before coming into leaf.
Most of the species in the family Myricaceae are subtropical. In the Tertiary it was well represented also in Europe but nowadays bog myrtle, also known as sweet gale, is the only European species in its family. It is a poisonous and aromatic plant which strongly favours oceanic climate. It spreads efficiently by means of runners. There are resin vessels in its leaves, stem, and inflorescences from which essential oils are secreted. Their odour can best be felt when rubbing the leaves.
Bog myrtle was earlier used instead of hops for flavouring beer. It made the beer stronger but also caused a worse hangover and headache. Shoots and bark has been used for tanning and the leaves, roots, and flowers in dyeing as they yield a yellow colour. Bog myrtle leaves were also mixed with pipe tobacco to make it stronger. In addition, it was used as a herbal medicine, and to repel moths and vermin.