Ilex aquifolium (common holly) is a familiar British native tree with dark evergreen prickly leaves, small greenish flowers, and characteristic red holly berries in autumn and winter (on female trees with a male tree nearby), until they have all been eaten by the birds.
There are many varieties of ilex aquifolium. Ilex aquifolium J. C. van Tol is generally free from spines, and is self pollinating. So a solitary plant will produce berries. Ilex aquifolium 'Argentea Marginata' has broad silver bordered leaves. Ilex aquifolium 'Alaska' has similar leaves and berries to the species, while the plant has a more upright and narrow habit.
Ilex x mersevaea has blue green leaves and red beries, rather similar to ilex aquifolium with bluish leaves.
Ilex crenata (Japanese holly) is a small leaved evergreen, which can be used as a box substitute. There are small white flowers followed by black berries.