Belfast Botanic Gardens Tree Archive

There are not many conifers that are deciduous; that drop all their needles in winter. Another in the Botanic Gardens is - the dawn redwood - and this month's tree, the swamp cypress, is superficially similar. However, the swamp cypress lacks the dramatic conical shape of the dawn redwood and has a much more graceful spreading shape. The Botanic Gardens specimen is still young, but its shape is already distinct from the dawn redwood. The leaves are also slightly different, the swamp cypress leaves tapering uniformly to a point, where the dawn redwood leaves remain parallel almost to the tip then narrow in sharply to a point. A distinctive and unique feature of the swamp cypress is the development of aerial roots in older plants. These structures, pneumatophores sometimes called 'knees', rise up from the ground around the trunk allowing the tree roots to absorb oxygen from the air and to trap sediment. This enables the tree to live in waterlogged soils and swamps. However the swamp cypress is not restricted to swamps and grows well in dry soils.