"Evergreen" keeps its leaves all year round. Needle-leaves trees such as pine come to mind first, but there are also evergreen broad-leaves trees. The example is the cold camellia whose flowers you can enjoy at this time of year. Is it a common feature of evergreen broad-leaved trees that the leaves are thick? The lifespan of the leaves is usually about one year, but those of some conifers exceed 10 years.