The Oak Marble Gall (also known as 'Oak Nut') is caused by a tiny gall wasp, Andricus kollari. Clusters of Oak Marble Galls can be found on oak twigs. They turn brown as they mature and emergence holes, from which the asexual adults have escaped, can be seen from autumn onwards.
This group captures all the small things which do not come under the other categories. It includes things like mosses, liverworts (together known as ‘bryophytes’) which play a vital role in regulating ecosystems because they provide an important buffer system for other plants, which live alongside and benefit from the water and nutrients that bryophytes collect.
Other small things found on our reserve are plant galls, a gall is an abnormal growth produced by a plant or other host under the influence of another organism.
Most galls are caused by fungi or invertebrates, they can occur on the stems, leaves, flowers, fruits, seeds and roots of plants, and a wide variety of plants are affected, including many very common species. Oaks and willows are particularly rich in galls, both of which grow here at Sevenoaks Wildlife Reserve.
Ordinary Moss, as its name suggests, is one of the UK's most common mosses and is found growing in lawns, on damp ground and in woodlands.
It is usually dark green but can be tinged yellow. It has branching stems that taper, with shiny, oval, pointed leaves that have fine teeth on their edges.
Oak Marble Gall