Their Irish name An Sliabh Riabhach, anglicized 'Slieve Reagh', means "the brindled mountain(s).

[1] The southern part of the hills is largely afforested with conifer plantations, on the northern side there is extensive heathland and blanket bog.

The blanket bog occurs in most of the flatter areas and features such species as heather (Calluna vulgaris), with deergrass (Trichophorum cespitosum), hare’s-tail cottongrass (Eriophorum vaginatum), common cottongrass (Eriophorum angustifolium), bilberry (Vaccinium myrtillus) and crowberry (Empetrum nigrum).

The dry heath is more species-rich, with bell heather (Erica cinerea), green-ribbed sedge (Carex binervis), tormentil (Potentilla erecta), bent grasses (Agrostis spp.)

[3] The Ballyhoura Mountain Bike Park situated near under Seefin and Blackrock is the largest Trail network of its kind in Ireland.