Woody > Ilex > Ilex opaca > Ilex opaca
Ilex opaca
American Holly
Origin: Ilex opaca originally was used as a representation of friendship in the winter solstice celebrations. Today, because of its shiny green foliage and red berries, Ilex opaca is a representation of Christmas celebrations, and is often brought indoors for the holiday.
Mike's
Opinion
"
An excellent specimen plant and is often used for hedging. Brilliant Christmas themed colours make Ilex opaca popular in the holiday season. Widely considered one of the most interesting Holly trees by gardeners, because of its dense pyramidal shape. Since the berries on the female plants are the most sought after feature of Ilex opaca, grouping or planting in windbreaks or hedges is optimal as one male pollinate up to three females.
Michael Pascoe, NDP., ODH., CLT., MSc. (Plant Conservation)
"
| Family |
| Aquifoliaceae |
| Genus |
| Ilex |
| Species |
| opaca |
| Category |
| Woody |
| Type |
| Tree (evergreen) |
| Pronunciation |
| USDA Hardiness Zone |
| 5 - 9 |
| Canadian Hardiness Zone |
| 5a - 8a |
| Temperature (°C) |
| -26- ( -4) |
| Temperature (°F) |
| -14 - 24 |
| Height |
| 15 m |
| Spread |
| 10 m |
Photographs
Cultivars
click to expand
Description and Growing Information
Flowering Period
| General Description |
| Dense pyramidal shape with elliptic, dark green, spiked leaves. Female plants have an abundance of orange to red berries in autumn. |
| Landscape |
| Ilex opaca is often used in groupings or as a specimen plant and is widely considered one of the nicest Holly trees because of its dense pyramidal form, myriad of red berries and lustrous green foliage. |
| Cultivation |
| Ilex opaca thrives in acid soil in full sun, however it will tolerate partial shade. The plant prefers well drained, moist, loose, organic rich soil and is tolerant of road salt and pollution but will not tolerate harsh winds.Ilex opaca requires no regular pruning. |
| Shape |
| The tree has a densely pyramidal shape. |
| Growth |
| Medium |
| ID Characteristic |
| The plants most notable features are the orange - red berries that appear on female plants, and the deep green, spiked foliage. |
| Pests |
| It may be susceptible to many pest and diseases, the most prominent being scale and leaf miner, but also including red mite, leaf spots, canker, tar spot, twig dieback and powdery mildew. |
| Habitat |
| Ilex opaca thrives in most soils, however it does best in soils that are moist, loamy, and well-drained. It prefers acid soil and is tolerant of salt and pollution. |
| Bark/Stem Description |
| I. opaca has smooth, uninteresting bark, grey in colour and often susceptible to lichens growth which does not adversely affect the plant. |
| Flower/Leaf Bud Description |
| The vegetative buds on I. opaca are ovoid shaped, approximately 1.5-3 mm in length. Buds are greenish – brown in colour and lightly pubescent. |
| Leaf Description |
| The leaves on I. opaca are dark green, spiked, elliptic and approximately 4 -9 cm long and 2- 4.5 cm wide. |
| Flower Description |
| Approximately 5 mm, dioecious, four lobed, white flowers appear on Ilex opaca from April to June, later than most evergreens. Male flowers are staminate appearing in groups of three, while female flowers are pistillate. |
| Fruit Description |
| The fruit on I. opaca is round, bright red fruit and is 6- 13 mm in diameter. Ilex opaca fruit reaches full maturity in October on a 3 mm stalk and remains on female plants through the winter into the spring. |
| Colour Description |
| It is notably deep green with bright orange – red berries. |
| Texture Description |
| Ilex opaca has a medium texture. |
| Propagation |
| Seed propagation is quite common, the embryos require further maturing and must experience a 60 day warm period at 20 °C, after which the seed begins to germinate. I. opaca will root adequately through hardwood cuttings in autumn to the middle of winter. It is beneficial to collect cuttings from a plant that has a dark terminal bud as it has reached full maturity and will root with more success. |
References
Dirr, Michael A. Dirr’s Encyclopedia of Trees and Shrubs. Portland, Oregon: Timber Press. 2011.
Rodd, Tony, and Geoff Bryant. Plant Finder. Richmond, Ontario: Firefly Books Ltd. 2007
top