Swamp Cypress (Taxodium distichum)

Exotic non native.  This attractive fast-growing conifer likes moist to wet, sheltered sites.  It provides a beautiful contrast to evergreens in the autumn, turning rusty red/gold.  Its feathery green new foliage appears early summer. Attractive mangrove-like aerial roots are a real feature, allowing the tree to breathe underwater. Deciduous. Hardy.
 
These are sold in 10 litre pots and will be over 1m tall.  When mature, this tree can grow to 25 metres.