A vocabulary of landscape — a landscape of words 1467 entries

alder-carr

AWL-der KAR
Wet woodland dominated by alder, standing on waterlogged peat or floodplain silt — dark, tangled, footing unreliable, the ground between the trunks holding pools and tussocks and fallen wood. It is a stage rather than an end state: Alder colonizes bog, dries it enough for other species, and is then shaded out by what it made possible.
Etymology
Alder is Old English alor. The word doing the work here is carr, from Old Norse kjarr, brushwood or thicket, often in the compound kjarr-mýrr, a marsh grown over with scrub. It came into Middle English as kerr or carr.
Notes
Not a fen, which is open, and not a bog, which is acid and fed by rain rather than groundwater. The largest tracts in Britain are on the Norfolk Broads, which are themselves flooded medieval peat diggings — a habitat sitting on top of an industry nobody remembered until the 1950s.