Its evergreen nature has made this tree very important in ritual over the millennia, for whereas the winter appears to bring about the death of deciduous trees, to be followed by a rebirth in spring, holly appears immortal. Of course holly does lose its leaves, but at a fairly constant rate throughout the year and anyone attempting to crawl under a holly tree becomes quickly aware of this when hands and knees receive sharp prickly reminders, especially as the dead leaves are slow to rot.
By bearing its tough, waxy leaves throughout the winter holly is able to take advantage of early spring sunshine but the downside is that its leaves are available to hungry animals which can, and do, browse the trees. Interestingly, studies in south-eastern Spain, reported in the Botanical Journal of the Linnean Society, have shown that when holly is browsed there is a rapid response at molecular level, with far spinier leaves being produced. This tendency for leaves on higher branches to be free of spines has been known for centuries and a vague memory led me to a poem by Robert Southey. In it he wrote:
No grazing cattle, through their prickly round,
Can reach to wound;
But, as they grow where nothing is to fear,
Smooth and unarmed the pointless leaves appear.
The Holly Tree, Robert Southey 1774-1843
Be that as it may, even the smooth leaves are tough and unpalatable to many animals and are avoided where better browsing is available. Even insects tend to eschew (rather than chew!) the leaves but one exception is the fly, Phytomyza ilicis. Here its very familiar mine is photographed on a spine-free holly leaf, but they are just as happy on a spiny leaf as, for this insect, the spines are irrelevant. (The caterpillars of the Holly Blue butterfly, Celastrina argiolus, normally restrict their diet to the flowers and buds.)
Phytomyza ilicis on a holly leaf in the churchyard at Norton,
Northants. 22 October, 2016
Cherry Laurel is familiar in gardens, often being used for
hedging. Daventry, 21 October, 2016