feed within the leaf) which leads to a brown blotch with black frass. Later, two successive cones are formed by folding the tip of a leaf downwards. In Britain, 14 galls have been recorded on ash. The British Plant Gall Society defines a gall as "... an abnormal growth produced by a plant under the influence of another organism". Ash dieback Ash dieback is caused by the fungus Hymenoscyphus fraxineus which was previously known as Chalara fraxinea. Research into the genetics of the resistance of ash (Fraxinus excelsior) has shown that resistance does occur in European populations, but at least for the samples tested, it is neither common nor strong. Due to the importance of F. excelsior as a host, Jönsson and Thor 2012 find that rare/threatened lichens face an unusually high (0.38) coextinction risk probability vis-a-vis the host tree in the wooded meadows of Gotland, Sweden. Genome The genome of Fraxinus excelsior is being sequenced by two groups of scientists in the United Kingdom. A group at Queen Mary University of London led by Richard Buggs are sequencing the self-pollinated offspring of a tree from Worcestershire, held by the Earth Trust. A group at the John Innes Centre and The Genome Analysis Centre led by Allan Downie are sequencing "Tree 35" from Denmark, discovered by Erik Kjær, which has survived 8 years of ash dieback. Uses The resilience and rapid growth made it an important resource for smallholders and farmers. It was probably the most versatile wood in the countryside with wide-ranging uses. Until World War II, the trees were often coppiced on a 10-year cycle to provide a sustainable source of timber for fuel and poles for building and woodworking. The colour of the wood ranges from creamy white to light brown, and the heart wood may be a darker olive-brown. Ash timber is hard, tough and very hard-wearing, with a coarse, open grain and a density of 710 kg/m3. It lacks oak's natural resistance to decay, and is not as suitable for posts buried in the ground. Because of its high flexibility, shock resistance, and resistance to splitting, ash wood is the traditional material for bows, tool handles, especially for hammers and axes, tennis rackets, and snooker cue sticks, and it was extensively used in the construction of early aircraft. Ash was commonly used green for making chair frames which would be seated with another timber or