Cannabis has long been used for hemp fibre, for hemp oils, for medicinal purposes, and as a recreational drug. Industrial hemp products are made from cannabis plants selected to produce an abundance of fiber. To satisfy the UN Narcotics Convention, some cannabis strains have been bred to produce minimal levels of tetrahydrocannabinol (THC), the principal psychoactive constituent. Many plants have been selectively bred to produce a maximum of THC (cannabinoids) which is obtained by curing the flowers. Various compounds of the plant, including hashish and hash oil, are extracted from the plant.
A fruit tree is a tree which bears fruit that is consumed or used by humans and some animals â all trees that are flowering plants produce fruit, which are the ripened ovaries of flowers containing one or more seeds. In horticultural usage, the term 'fruit tree' is limited to those that provide fruit for human food. Types of fruits are described and defined elsewhere (see Fruit), but would include "fruit" in a culinary sense, as well as some nut-bearing trees, such as walnuts. The scientific study and the cultivation of fruits is called pomology, which divides fruits into groups based on plant morphology and anatomy. Some of those groups are: Pome fruits, which include apples and pears, and stone fruits, which include peaches/nectarines, almonds, apricots, plums and cherries.