Oxydendrum arboreum

Scientific name: Oxydendrum arboreum

Author: Augustine-Pyramus de Candolle (1778–1841)

Common name: Sorrel Tree, Sourwood, Lily-of-the-valley Tree

Family: Ericaceae


Oxydendrum arboreum   


Experience autumn magic even though winter has officially started! The Rhododendron species beds RS110 to RS115 start at the Restaurant end of the Visitor Centre and surround the barbecue area on its northern and eastern sides.

Here you will find our collection of rhododendron and azalea species, many of which have been collected from their natural habitat or, as we often say, ‘from the wild’. Other members of the plant family Ericaceae, to which the rhododendrons and azaleas belong, are also displayed in these beds. It is interesting to see just how many members of this plant family produce good autumn colour, including species of Agapetes, Enkianthus and Lyonia.

Our feature plant is a short, flat walk along the first path on your left as you walk beside the RS Beds, from the Visitor Centre to the barbecue area.

It also belongs to the diverse Ericaceae plant family and has previously been placed in the Andromeda and then Lyonia genera. Now considered to be the only member of the genus Oxydendrum, it is therefore said to be a monotypic genus. The Greek oxys sharp and dendron tree refer to the sour or acid-tasting foliage alleged to slake thirst, provide a tonic, act as a diuretic and possibly be of use to treat fever.

Well-drained, gravelly, acid soils on stream-side ridges from Pennsylvania west to Indiana and south to Florida in eastern USA are 'home' to these small trees with deeply furrowed bark and fragrant white flowers. In cultivation they have a reputation for being fussy about their requirements. However, they are slow growing, seldom reach 20 metres in height, have a graceful arched form, summer flowers and autumn colour. Such attributes recommend them as a specimen tree in full sun or semi-shade areas. Seed sown in autumn or spring, or softwood cuttings taken in summer are the usual propagation methods.