There are several types of grassland within the site and their origination is dependent upon aspect, soil, grazing intensity and how areas of the common have been managed. The site supports several species of rare orchid such as the bee orchid, the frog orchid and the musk orchid. Spoil and scree from disused quarries provide conditions for plants which grow in more open habitats.[1]
The Bouguetia and phillipsiana beds of the upper Middle Inferior Oolite are confined to a very limited outcrop on Cleeve Common. These units, which have distinctive fossil faunas of bivalves, gastropods and brachiopods, are only visible at Rolling Bank Quarry. These outcrops are thus unique and are considered the only examples of part of the Middle Jurassic, Bajocian, time interval in Britain. The Inferior Oolite hill top of Postlip Warren shows the best example of ridge and trough features.[1]