Each country in the European Union has its own definition of a forest and the European Commission has defined forestland as having at least 20% canopy closure (10% in the Mediterranean forests) and a minimum area of 0.5 ha. (1 ha. = 0.01 kmÂ²). Elsewhere, the definition of a tree can vary.
Lunula: the crescent-shaped area at the base of the human fingernail.
A cannula needle is a stainless steel, hollow needle encased by a hollow plastic tube. The needle closely resembles a medical syringe tip, except that the needle isn't always attached to a plastic barrel for extracting fluids or tissue.