New leaves of tarata or lemonwood (Pittosporum eugenioides) in the form of overwintering buds are protected by these overlapping bud scales. Most woody plants of the northern hemisphere form overwintering buds to protect new leaves from the cold, or to prevent them from drying out. But this adaptation is uncommon in New Zealand’s milder climate. Of 45 genera, only three have numerous, reasonably large bud scales – Pittosporum, Aristotelia, and the tree species of Metrosideros (pōhutukawa and rātā). Southern beech (Nothofagus) trees have many overlapping bud scales. Most buds of woody, flowering plants species in New Zealand have no protection or only partial protection (hairy leaves or a secretion). Unprotected buds are a feature of plants of the tropics.