Clarke's Pool Meadows Nature Reserve (also a Site of Special Scientific Interest) comprises two fields on level ground at the top of a low hill just beyond the eastern edge of the Forest of Dean, one mile from the River Severn, and underlain by Old Red Sandstone which results in a mix of neutral and slightly acidic soils. As the fields have been managed for many years as traditional pasture, without use of fertilisers or pesticides, this has created an ideal habitat for a great variety of grassland wildflowers; of the rarer species, by far the most abundant is green-winged orchid, with approximately 45,000 plants blooming here between April and May, while the reserve is also home to twayblade and meadow saffron, together with various commoner species such as yellow rattle, cowslip and pignut.
The wildflowers are found mostly in the larger, eastern field, which has been occupied by pasture for the longest period; the smaller, western field was cultivated until sometime in the 19th century, though the presence of indicator species of ancient woodland in the hedgerow and thin belt of trees between the two, such as bluebell and wood anemone, suggests that all this area was originally forested. The hedgerows and adjacent taller undergrowth provide habitat for several species of animals including field vole, green woodpecker and barn owl.
The meadow is named for a small pool along the eastern edge, in summer rather hidden by the undergrowth. Clarke was, and is, a common surname for people in the nearby village of Blakeney, but it is not recorded which person the pool commemorates.
Because of the abundant, varied wildflowers and the undisturbed nature of the soil, this site is recognised as one of the finest hay meadows in the county, and it became a nature reserve in 1997, the same year as the SSSI designation.
The entrance to Clarke's Pool Meadows Nature Reserve, at the south side of the eastern field, is a short distance along a country lane east of the A48, half a mile south of Blakeney, and is identified by a faded Gloucestershire Wildlife Trust noticeboard, describing some of the plants and animals found here. In the spring an unofficial path develops around the perimeter of the two fields, and visitors are requested not to wander all over the grassland in order to protect the wildflowers. The grass is cut for hay in late summer, after which a few late-blooming species appear, including the meadow saffron. About half an hour is sufficient to visit the reserve and inspect the various flowers. The densest concentration of orchids, both green-winged and twayblade, is towards the east and north sides of the eastern field. The former also occurs in the less common all-white version, contrasting with the usual dark purple. Occasionally a single plant produces flowers in both shades.