Ivy belongs to the family Araliaceae, a family of flowering plants to include a diverse array of habitual form such as trees, shrubs and lianas. Within this family lies the genus Hedera, a small group of evergreen climbing plants found across the Northern hemisphere, in which the species ‘Ivy’ (Hedera helix) as we English folk know it lies. But what may not be that well know to people is that there are several subspecies found in the UK, the number of which changes depending on which reference you are reading, however it is generally said that 2 subspecies can be found in the UK:
- H. helix ssp helix
- H. helix ssp hibernica
Next time you’re passing some ivy on your travels, the chances are you are looking at the ssp helix, as this is the most common, but you may be excited to find something more interesting than what you just assume.
Ivy is extremely underrated by people for its value for wildlife. Many dismiss it as a vigorous nuisance, dominating areas of shade and smothering some trees to the extent that they are unrecognisable. But is this such a bad thing? Ivy has many benefits such as adding structural diversity to habitats, providing cover for animals in winter and producing fruits in winter when other food sources are low. As well as this, ivy is known as one of two primary food plants of the holly blue butterfly, a species which is doing well amongst the ranks of butterfly numbers…perhaps helped due to the success of this plant.
The most striking thing to me about ivy is it’s berries. These are poisonous to humans, but act as a really useful food source to birds and mammals which eat the berries and disperse the seeds. Certainly, ivy is a must species for any wildlife garden wanting to attract birds in the winter. Many birds, such as blackbirds and thrushes, eat the berries. As well as this, when ivy is flowering in Sep/Oct, species such as hornets, hoverflies, bumblebees, red admirals, small tortoiseshells and peacock butterflies are known to drink the nectar. Branches and leaves of ivy also provide shelter and nesting sites for birds, and a ready supply of insects can be found living on and around them.
Although often unmistakable, the one confusing thing about ivy to the amateur is that the leaves vary with age. As shown below, only juvenile leaves (non flowering) produce the characteristic lobed leaf margins which we associate with ivy, whereas the mature (flowering) leaf margins are less lobed and more undulate. I must admit this difference has fooled me before!
The important thing to remember is that Ivy is not parasitic, it only receives structural support from it’s host, so is not a threat to healthy trees. Regular maintenance such as trimming back can prevent it from becoming too dominant and suppressing other plant species.