Holly

Appearance

Holly is an evergreen tree growing to 10–25 m tall with a woody stem as large as 40–80 cm, rarely 1 m or more, in diameter The leaves are 5–12 cm long and 2–6 cm broad; they are evergreen, lasting about five years, and are dark green on the upper surface and lighter on the underside, oval, leathery, shiny, and about 5 to 9 cm long. In the young and in the lower limbs of mature trees, the leaves have three to five sharp spines on each side, pointing alternately upward and downward, while leaves of the upper branches in mature trees lack spines.

The flowers are white, four-lobed, and pollinated by bees. Holly is dioecious, meaning that there are male plants and female plants. The sex cannot be determined until the plants begin flowering, usually between 4 and 12 years of age. In male specimens, the flowers are yellowish and appear in axillary groups. In the female, flowers are isolated or in groups of three and are small and white or slightly pink, and consist of four petals and four sepals partially fused at the base.

The fruit is a red drupe, about 6–10 mm in diameter, a bright red or bright yellow, which matures around October or November; at this time they are very bitter due to the ilicin content and so are rarely eaten until late winter after frost has made them softer and more palatable. They are eaten by rodents, birds and larger herbivores. Each fruit contains 3 to 4 seeds which do not germinate until the second or third spring. The fruit only appears on female plants, which require male plants nearby to fertilise them.

Distribution

Today, holly is found in western Asia and Europe in the undergrowth of oak forest and beech forest in particular, although at times it can form a dense thicket as the dominant species. It requires moist, shady environments, found within forests or in shady slopes, cliffs, and mountain gorges.

During the Cenozoic Era, the Mediterranean region, Europe, and northwest Africa had a wetter climate and were largely covered by laurel forests. Holly was a typical representative species of this biome, where many current species of the genus "Ilex" were present. With the drying of the Mediterranean Basin during the Pliocene, the laurel forests gradually retreated, replaced by more drought-tolerant sclerophyll plant communities. The modern "Ilex aquifolium" resulted from this change. Most of the last remaining laurel forests around the Mediterranean are believed to have died out approximately 10,000 years ago at the end of the Pleistocene.

Habitat

Holly is a rugged pioneer species that preserves and enriches the soil facilitating colonization by others. It is an ecological indicator of a well-preserved or recovering area with little human intrusion. It prefers relatively moist areas, up to 600m in elevation, and tolerates Mediterranean summer drought and frost. The plant is common in the garrigue and maquis and is also found in deciduous forest and oak forest.

Pure stands of hollies can grow into a labyrinth of vaults in which thrushes and deer take refuge, while smaller birds are protected among their spiny leaves. After the first frost of the season, hollies' fruit becomes soft and falls to the ground serving as important food for winter birds at a time of scarce resources.

The flowers are attractive as nectar sources for insects such as bees, wasps, flies, and small butterflies.

It is an invasive species on the West Coast of the United States and Hawaii.

Uses

Holly is rarely used medicinally due to its toxicity, but is diuretic, relieves fevers, and has a laxative action.

It contains saponins, the xanthine theobromine, and a yellow pigment, ilexanthin.