Alongside the River Taff in Sophia Gardens, Cardiff there are a number of planted Holm Oaks Quercus ilex. These are evergreen oaks have leaves with a very downy underside, which according to Edlin is
‘..to slow air movement through breathing pores.'(Edlin p112)
and is a characteristic of other evergreen oaks such as Cork Oak and Live Oak. None of these are native to Britain but apparently Q ilex has been getting itself into trouble by self setting and ‘invading’ grassland, and is increasingly being seen as an invasive non native species.
To the casual observer, Q ilex is often confused for Holly Ilex aquifolium, due to both its evergreen nature and the fact that it has variable leaves which may also have short spines. Q ilex however has the distinctive downy undersides of the leaves whereas I aquifolium is glabrous (without hairs) throughout.