About the reserve

Both reserve areas lie within an extensive area of ancient semi-natural woodland and contain a variety of woodland plants typical of base-rich soils. Botanically-rich fen vegetation has developed, which includes marsh helleborine and fragrant orchid, as well as various sedges and mosses. This wetland vegetation then intergrades with plants of moist woodland edge, such as marsh thistle, bluebell and nettle-leaved bellflower. The waters of the adjacent Pentaloe Brook are well-oxygenated and unpolluted, and contain a number of interesting species, including bullhead, river limpet and a variety of stonefly and mayfly larvae.  

In recent years, the surrounding conifers have been cleared, and the Glen now has a more open and sunny aspect. This makes it more attractive to butterflies like silver-washed fritillary and the scarce wood white. Pentaloe is also home to a very rare and distinctive crane-fly, Gonomyia (Protogonomyia) alboscutellata, only known from three other sites in Britain.