Styrax japonicus (野茉莉; also エゴノキ, egonoki),[2] also known as the Japanese snowbell, is a species of flowering plant in the family Styracaceae, native to Korea, Japan, and Southern China. Growing to 12 m (39 ft) tall by 8 m (26 ft) broad, it is a graceful, spreading deciduous tree with oval, upward-facing leaves which occasionally turn yellow or orange before falling in autumn. Masses of slightly fragrant, bell-shaped white flowers hang from the branches in summer, followed by fruits (drupes) which resemble olives in both shape and colour.[3][4]
It is hardy down to −15 °C (5 °F), but prefers a sheltered position in full sun or dappled shade, with acidic or neutral soil.[3]
Due to its plentiful flowers, the tree has been widely cultivated in Western gardens.[5] Properties such as analgesic,[6] hypoglycaemic,[7] and antibacterial[8][9] effects have been observed in extracts and isolates from the flowers, stem-bark, and leaves, respectively.
Etymology
Styrax japonicus is a member of the Styracaceae family, with the authority of Siebold & Zuccarini. Styrax is a genus whose members produce aromatic resins. The Latin specific epithet japonicus means "from Japan".[5]
The Japanese common name, egonoki (野茉莉; エゴノキ), originates from how the fruit annoys the throat and tongue when put in the mouth — egui (えぐい) or egoi (えごい) describes something that evokes a repulsive, bitter flavor.[10][11]
Description
The appearance of Styrax japonicus ranges from a large shrub to a small tree.
Raceme arrangement of
Styrax japonicus flowers.
Leaves
Leaves are simple in alternate arrangement. They are upward-facing with an oblong shape, dark green and shiny.[12]
Flowers
The flowers of S. japonicus are pendulous and arranged in a raceme inflorescence. When in bloom, they evoke a light fragrance. The petals are commonly colored white; however, the petals of the 'Pink Chime' cultivar is pink.[12] The five-petaled, bell-shaped corolla is around 2-3 cm long and typically blooms in late spring. The corolla is surrounded by 5-toothed calyx.[13] They are perfect and perigynous with prominent yellow stamens.
Unripe fruits of
Styrax japonicus.
Fruit
The gray-green drupe-like capsule fruits of S. japonicus are around 2 centimetres (0.79 in) long, appearing around August and September.[12] Long stalks extend from each drupe and attach with star-shaped calyx. Each fruit contains one seed.[14]
Distribution and habitat
Distribution
Styrax japonicus is native to Korea, Japan, and Southern China. It has the largest distribution out of the members in the genus Styrax.[13][15] An attractive landscape tree, it can be found commonly within parks and gardens.
Habitat
Generally pest-resistant and disease-resistant,[12] weaker trees may be susceptible to the ambrosia beetle.[16] It is cold hardy to −15 °C (5 °F),[3] with a classification of USDA hardiness zones ranging from 5-8, depending on the cultivation[16] and provenance.[15]
S. japonicus prefer acidic or neutral soil.[3] They should be planted with full sun or part sun/part shade exposure,[12] protection from cold and dry wind, and provided consistently moist soil.[14]
There is no known threat to the conservation of the species. The IUCN Red List of Threatened Plants ranks S. japonicus as "Least Concern", last assessed in 2019.[1]
Cultivation
The first introduction of Styrax to the West was by Richard Oldham in 1862.[17] Styrax japonicus is known to be one of the most cultivated species in North American and European gardens[13] and one of the most common Styrax cultivars.[15] It has been cultivated for its pendulous forms, flower color, dwarfism, foliage colorization (such as burgundy leaves), and temperature tolerance.[13]
In particular, the Japanese name Benibana (ベニバナ) Group, refers to cultivars with pink flowers and is inclusive of the cultivar 'Pink Chimes'.[15][18] Japanese gardeners use the term Beniego (ベニエゴ) to describe this cultivar.[19]
The cultivar 'Fargesii', with larger flowers and leaves than the typical species, has gained the Royal Horticultural Society's Award of Garden Merit.[20][21]
Pink-hued flowers of
Styrax japonica 'Pink Chimes'.
Common Cultivars include:
- 'Angyo Dwarf'
- 'Carillon'
- 'Crystal'
- 'Emerald Pagoda'
- 'Evening Light'
- 'Fargesil'
- 'Fragrant Fountain'
- 'Issai'
- 'Pink Chimes'
- 'Snow Cone'
