An Introduction to the Survey of Higher Plants made by M & J Iliff 2007
In former times Cwm Rhaeadr would have been part of the Mynydd Mallaen moor, whose side valleys are often sheltered and species rich.
The moorland character is revealed by plants like Blechnum (Hard Fern) which is very frequent, Juncus squarrosus (Heath Rush) and Wahlenbergia (Ivy-leaved Bellflower).
It is noticeable that the common hedgerow plants like the Red Campion and Cow Parsley have not been seen.
We know that more recently there have been many small farms on the site, but hardly a trace of any of these remain in the form of common weeds like Nettles and Docks which can usually be found as evidence of habitation.
The only obvious instance consists of two enormous Box trees and a variety of large-flowered Victorian Daffodils growing not far from the buildings presently used by the scouts (Cwm Rhaeadr barns).
Due to the shading effect of the trees the greater part of the species are to be found, fortunately for the passer-by, on the roadside verges: many of these are very species rich, showing a great variety of composites, vetches, clovers and umbellifers and include in the drier parts, an abundance of the small pink Centaury.
The ditches often have an abundance of Rushes and Sedges and the carpet-forming pink Bog Pimpernel.
Perhaps the most varied area is the riverside path from the bridge to the hairpin bend below the waterfall. Adjacent to the bridge is quite a large colony of the graceful, many-branched Equisitum sylvaticum (Wood Horsetail), only appearing in the summer months. Also alongside the path are to be found Solidago (Golden Rod), Wahlenbergia and large clumps of Politricum (Haircrop Moss).
Much of the variety of plantlife in Cwm Rhaeadr lies in its abundance of Mosses and Liverworts which are fully considered in the parallel survey by Mr Ray Woods.