Lucerne (Medicago sativa) is thought to have originated somewhere in north-western Iran and north-eastern Turkey. Varieties range from winter-dormant, through to winter-active lucerne.
Prime hay is the classification given to hay that has good green colour, plenty of intact leaf, and relatively finesoft stems. It may contain up to 10% of other plant material, such as grass, but should be free of prohibited weeds and mould, fungi, or weather damage. There is actually a grade above prime, Choice, that is more pure, and of a higher standard all around. These classifications do not specify age, but most people assume prime hay to be prime green, which is as fresh as possible (generally less than a month).