The fen meadow, in which blunt-flowered rush, Juncus subnodulosus, is dominant, grades into open flushes.

These are, in particular, Monkey-flower, Purple Moor-grass and Blunt-flowered Rush.

In the community in the western part of the mire, Blunt-flowered Rush, Purple Moor-grass (Molinea caerulea) and Carnation Sedge (Carex panicea) are abundant species, and this part of the mire is characterised by the presence of a number of species which favour base-rich conditions.

The fen meadow, in which blunt-flowered rush, Juncus subnodulosus, is dominant, grades into open flushes.

The larvae feed on the seeds of Juncus articulatus, Juncus effusus, Juncus inflexus, Juncus subnodulosus, Juncus acutiflorus and Juncus conglomeratus.

Yanal Bog, a calcicolous mire near Sandford is designated for its plant communities, within which grow Black Bog-rush (Schoenus nigricans) and Blunt-flowered Rush (Juncus subnodulosus), two plant species rare in southwest England.

The plant communities of the mire are nationally rare in Britain, and support two species, Black Bog-rush (Schoenus nigricans) and Blunt-flowered Rush (Juncus subnodulosus), which have restricted distributions in south-west England, and a number of species which are localised in the Avon area.