Hazel

The hazels (Corylus) are a genus of deciduous trees and large shrubs native to the temperate northern hemisphere. The genus is usually placed in the birch family Betulaceae,   though some botanists split the hazels (with the hornbeams and allied genera) into a separate family Corylaceae.

Wandlore
A sensitive wand, hazel often reflects its owner’s emotional state, and works best for a master who understands and can manage their own feelings. Others should be very careful handling a hazel wand if its owner has recently lost their temper, or suffered a serious disappointment, because the wand will absorb such energy and discharge it unpredictably.

The positive aspect of a hazel wand more than makes up for such minor discomforts, however, for it is capable of outstanding magic in the hands of the skillful, and is so devoted to its owner that it often ‘wilts’ (which is to say, it expels all its magic and refuses to perform, often necessitating the extraction of the core and its insertion into another casing, if the wand is still required) at the end of its master’s life (if the core is unicorn hair, however, there is no hope; the wand will almost certainly have ‘died’).

Hazel wands also have the unique ability to detect water underground, and will emit silvery, tear-shaped puffs of smoke if passing over concealed springs and wells.