Breaking bud of Aesculus hippocastanum

Expanding shoot of the horse chestnut, Aesculus hippocastanum. The picture shows a breaking terminal bud, and illustrates how the tree protects itself against cold winter conditions. At the bottom of the picture, folding back, are the scales that covered the shoot in its dormant period.They are covered with a shiney water-repellent sticky resin (dark brown) During dormancy, only these resin-covered tips of the scales are exposed to the atmosphere. In the picture centre and above, other scales have expanded more, and are less resinous (orange hue). The developing leaves are tightly packed together with further insulation in the form of hairs ( pale green, above centre ). Although widely planted throughout Europe as an amenity tree, in its native regions of Greece, Bulgaria and Macedonia, horse chestnut is classified as Near Threatened, and it may already be extinct in Albania