![]() ![]() They have rusty brown, over-lapping scale leaves (which protect the bud throughout the winter months. Buds tend to be clustered near the end of the winter twig. When this happens, strange shaped galls form that can be green, yellow or red in colour. Sometimes galls form, for example when the wasp, Andricus quercuscalicis lays its eggs in the young acorns of pedunculate oaks. In some years, oak trees produce acorns in vastly increased numbers - the so called mast years. In the sessile oak, the acorns appear to sit on the twigs. Branches begin dying near the top of the tree, and clusters of honey colored. One to four acorns are attached to each peduncle. Above- ground symptoms are undersized, discolored and prematurely dropping leaves. The acorns are up to 2-2.5 cm in length, and (in the pedunculate oak) are attached to a peduncle / acorn stalk (3-7cm in length). When the female flowers are fertilised, they will develop into acorns. The female flowers are very small and found in the axils of the leaves. The male flowers are drooping catkins and their pollen is dispersed by the wind. The Oak produces male and female flowers. The bark of a younger oak is shown for comparison collection of oak buds on twig Bark on mature oakBark on younger trees bark on y ounger tree Flowers and Fruits The bark may support a rich lichen flora. ![]() The bark is grey and on older trees fissures may be seen. They have rusty brown, over-lapping scale leaves. simple leaf of oak with lobes and petiole petioles not obvious petioles well defined distinct petioles small hairs near main vein Buds, Bark & Stemīuds tend to be clustered near the end of the winter twig (see image below). Leaves of the sessile oak may have fine hairs on the underside, more noticeable on the main vein or midrib of the leaf. In the pedunculate oak, the lobes tend to taper into the stem so that the leaf stalk / petiole is barely noticeable. There are 5 to 7 lobes on each side of the leaf. The leaf margin / edge is lobed and wavy. In the pedunculate oak, the leaf stalks (petioles) are quite short (less than 0.5cm) whereas in the sessile oak the leaf stalks are much more obvious (1 to 1.5 cm in length). The two (main) species of oak differ in the length of the leaf stalk / petiole. The leaves are arranged alternately around the stem. There are two main types / species, S essile Oak ( Quercus petraea) and Pedunculate Oak ( Quercus robur), and they cany hybridise. It has been used in building, for example in cruck frame structures, young wood can stain the hands, due to the presence of tannins). The wood of oak trees is good to work with, as it cleaves well. Oak is a keystone species in many habitats. The species supported range from hundreds of insects and spiders, dozen or birds, fungi, lichens etc. Such veteran oaks support an incredible range of other organism, in excess of 2000 other species interact / are dependent on oak trees in some way. ancient trees being 500 or more years old. Oaks are long lived trees, many become veterans. ![]()
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