The site consists of areas of calcareous fen wetland and associated carr woodland and meadow along the Little Ouse river which marks the county boundary.

It is notable for being an internationally important site for the rare black bog rush Schoenus nigricans and saw sedge Cladium mariscus plant species.

[8] Dominant species tend to be black bog rush Schoenus nigricans, saw sedge Cladium mariscus and purple moor grass Molinia caerulea, with species such as fen orchid Dactylorchis praetermissa, devil’s bit scabious Succisa pratensis, long-stalked yellow sedge Carex lepidocarpa, quaking grass Briza media, parnassus Parnassia palustris and a number of rare mosses also found in these areas.

Different plants are associated with this vegetation, increasing biodiversity to include species such as hemp agrimony Eupatorium cannabinum, purple loosestrife Lythrum salicaria and great hairy willowherb Epilobium hirsutum.

[8] Surrounding meadowlands and ditches support other species, including, for example, ragged robin Lychnis flos-cuculi, marsh marigold Caltha palustris.