Article from Bean's Trees and Shrubs Hardy in the British Isles
Recommended citation
'Leucothoe' from the website Trees and Shrubs Online (treesandshrubsonline.
We have published this stub genus article as part of a wider programme of work, beginning in early 2025, to bring the nomenclature of articles in line with modern treatments. Historic Bean text will appear under its correct modern name, with appropriate synonymy and adapted where necessary, until we have funding to update the articles entirely. If you would like to sponsor this genus please contact editor@treesandshrubsonline.org
Now a shadow of its former self, when Bean’s latest (1981) edition was published, Leucothoe contained around 45 deciduous and evergreen species distributed throughout North and South America, and (to a lesser extent) East Asia. Since then the genus has been thoroughly dismantled on phylogenetic grounds, sections having been split off into Agarista (mainly South American), Eubotrys (North American, deciduous) and Eubotryoides (Japanese, deciduous) – see the entries for those genera. As a result, the rump genus Leucothoe has been left with just five species, all evergreen and with an East Asian – North American distribution.
This process of revision and reordering was supported by molecular data and cladistics, but its conclusions notably concur with those of earlier taxonomists – from Nuttall (1843) to Sleumer (1959) – whose observations had gradually established a convincing infrageneric classification so strongly defined that surprise has been expressed that Leucothoe was maintained as a genus for so long (see Waselkov & Judd (2008), who give a detailed account of the taxonomic history).
Leaves alternate. Flowers in axillary or terminal racemes. Calyx of five nearly free lobes, which are imbricate (i.e., overlapping) in the bud. Corolla urn-shaped or cylindrical. Stamens ten, included within the corolla; anthers with or without awns and always without spurs at the base. Seed-vessel a round, flattened, loculicidal capsule.
Some species of Gaultheria closely resemble Leucothoe but can always be distinguished by their fruits. Lyonia differs in having the sepals valvate in the bud (i.e. not or just touching but not overlapping). Pieris also has valvate sepals.
The chief cultural need of the leucothoes is a moist, peaty soil or a sandy lime-free loam with leaf-mould added; they prefer semi-shaded positions. Propagation is by cuttings of half-ripened shoots.