Treen is a generic term given to useful domestic objects (such as pestle and mortars for grinding herbs and spices) or gifts (e.g. love tokens like Welsh love spoons). These objects are generally made out of beautiful country timbers.
Other examples include dairy bowls (often made out of sycamore), string boxes and snuff boxes.
Typical timber used was lignum vitae, popular for its hardwaring quality (incidentally, it’s the only wood that sinks), yewood, boxwood and such like.
Often owing to extensive use and the hardness of the timber, these objects have developed the most wonderful colour and patina.