Ilex crenata, also known as Japanese holly or box-leaved holly, is a species of flowering plant in the family Aquifoliaceae, native to eastern China, Japan, Korea, Taiwan, and Sakhalin.
It is an evergreen shrub growing to a height of 3–4 m (rarely 10 m) tall, with a trunk diameter up to 20 cm. The leaves are glossy dark green, small, 10–30 mm long and 10–17 mm broad, with a crenate (wavy) margin, sometimes spiny. The plants are dioecious (having separate male and female plants), with white, four-lobed flowers. The fruit is a black drupe (stone fruit) 5 mm diameter, containing four seeds. It grows well in acidic soil, between a pH of 3.8 and 6.0.[1] [2] [3]
Ilex crenata is grown as an ornamental plant for its dense evergreen foliage, and is a popular plant among bonsai enthusiasts.[4] It is superficially similar in appearance to boxwood (box), and is often used in similar situations, such as low hedging; but it can readily be distinguished from boxwood by its alternate, not opposite, leaf arrangement.[5]
Numerous cultivars have been selected, including plants with the leaves variegated (e.g. 'Golden Gem', 'Shiro-Fukurin'), dark green (e.g. 'Green Lustre'), or greyish-green (e.g. 'Bad Zwischenahn'); with yellow fruit (e.g. 'Ivory Hall'); and with an erect habit (e.g. 'Chesapeake'), spreading (e.g. 'Green Island', 'Hetzii'), or dwarf (e.g. 'Mariesii', 'Stokes').[3] The cultivars 'Golden Gem'[6] and ‘Fastigiata’ (Fastigiata Group)[7] have gained the Royal Horticultural Society's Award of Garden Merit.[8]