Ilex crenata, the Japanese holly or box-leaved holly (Japanese: イヌツゲ inutsuge) is a species of flowering plant in the family Aquifoliaceae, native to eastern China, Japan, Korea, Taiwan, and Sakhalin.
It is an evergreen shrub or small tree growing to a height of 3–5 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 3.7 and 6.0.
Ilex crenata is grown as an ornamental plant for its dense evergreen foliage, and is a popular plant among bonsai enthusiasts. 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.
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'). The cultivars 'Golden Gem' and ‘Fastigiata’ (Fastigiata Group) have gained the Royal Horticultural Society's Award of Garden Merit.
- ^ "Ilex crenata". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA). Retrieved 2018-01-12.
- ^ Osaka hundred trees: Ilex crenata Archived 2009-06-08 at the Wayback Machine (in Japanese; google translation)
- ^ Okayama Science University: Ilex crenata Archived 2007-10-11 at the Wayback Machine (in Japanese; google translation)
- ^ a b Huxley, A., ed. (1992). New RHS Dictionary of Gardening. Macmillan ISBN 0-333-47494-5.
- ^ "Japanese Holly Bonsai". BonsaiDojo.net. 31 January 2014.
- ^ "RHS Plant Selector". Royal Horticultural Society. Archived from the original on 2013-06-15. Retrieved 2013-05-20.
- ^ "RHS Plantfinder - Ilex crenata 'Fastigiata'". Retrieved 7 March 2018.
- ^ "AGM Plants - Ornamental" (PDF). Royal Horticultural Society. July 2017. p. 52. Retrieved 9 March 2018.