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Ash, a member of the olive family, is a very common tree. Although it is leafless at this time of the year, it is immediately recognizable by its jet black winter buttons. Unlike the sticky and glossy buttons of the horse chestnut from India, the big, pointed knobs of the ash are dry and dull.
The bud at the end of each branch, the terminal bud, is the largest and the largest of the buds. When he opens in the spring, he gives birth to a new branch rather than a leaf. When the bud opens, its scales fold and detach, allowing new growth to emerge and the length of the branch.
In the image above, this year 's big terminal bud is at the top right and bottom left, we can see the scars from the broken scales of last year' s terminal bud encircling the twig and forming a distinct belt scar.
It follows that the distance between this year 's large terminal bud at the top right and last year' s belt scar at the bottom left corresponds to branch growth over the course of the year. 39, last year.
We can look in the twig for the previous scars of the belt, but it is difficult, if not impossible, to see them because they are obscured by the growth of the perimeter of the twig.
But back to the big terminal bud that gives birth to a new branch. Note that he is flanked by two smaller buds. These are leafy buds and they tell us that the ash leaves are opposite: they grow in pairs, one in front of the other.
Also note that the next pair of leaf buds at the bottom of the branch is perpendicular to the pair above and below. Thus, not only are the leaves opposite, but they are alternate: they alternate a pair more and more to the left and right of a pair in front and back, and so on. It's an adaptation to get maximum light.
The shield – shaped scar of last year 's leaf is visible under this year' s leaf bud. The angle between each leaf and its twig is called the armpit. The bud of this year is therefore axillary: it develops in the armpit of the leaf of last year.
Finally, the lenticels are visible along the twig. These are tiny raised bumps covered with cork that form the breathable pores through which the living tissues of the twig internally exchange gases.
All of these features deserve to be examined outside on your local ash tree.
Wexford People
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