Portlethen Moss millennia of evaporation, further intensifying the soil acidity, fueled by organic matter decaying, with little drainage outlet. A layer of sphagnum moss would have developed at the benthic level of the bog, and additional sphagnum layers floated in mats atop the bog. At an intermediate level of evolution, thick peat layers formed from decay and carbonisation of the rotting sphagnum. Generations of carex and juncus flourished, leading to further decay of these materials and eventual heightening of the organic mass. Finally, secondary vegetation took root in the spongy sphagnum mats adding greater biomass to the bog.In some cases the heavy
Lough Derravaragh south of this raised bog. Much of the high bog possesses vegetation typical of an Irish Midland raised bog, with such species as ling heather ("Calluna vulgaris") and hare's tail cottongrass ("Eriophorum vaginatum"). The hummock-forming bog moss, "Sphagnum papillosum" has been recorded situated around one third of the high bog as has the more scarce "Sphagnum imbricatum". Overall, sphagnum covers around one-third of the high bog area. The centre of the bog is wet with stagnant water in places. The aquatic bog moss "Sphagnum cuspidatum" has been recorded in the hollows of the bog. There are dried-out channels of the