Agonis flexuosa, commonly known as Western Australian peppermint, Swan River peppermint, peppermint and willow myrtle, is a species of tree that grows in the southern half of Western Australia. It is easily the most common of the Agonis species, and is one of the most recognisable trees of Western Australia, being commonly grown in parks and on road verges in Perth.

Agonis flexuosa occurs mainly as a small tree, usually less than 10 metres tall, although it may grow to 15 metres. It has fibrous brown bark, and long, narrow, dull green leaves, with tightly clustered inflorescences of small white flowers in the axes. It grows in a weeping habit, and looks remarkably like the weeping willow from a distance. It is most readily identified by the powerful odour of peppermint that is emitted when the leaves are crushed or torn.

Agonis flexuosa occurs in a sub-coastal strip from just north of Perth south and then east beyond Bremer Bay. It flowers between August and December.

The species name flexuosa means "full of bends", referring to the zig-zag course of the stem, which changes direction at each leaf node. It was originally placed in the Leptospermum genus by Sprengel in 1819, but Schauer placed it in Agonis in 1844.

There are two recognised varieties: Agonis flexuosa var. flexuosa and Agonis flexuosa var. latifolia. The cultivar Agonis flexuosa 'Nana' is a dwarf form that is commonly seen in Perth as a hedge.

References

Flora of Western Australia | Myrtales