This variety of uncertain origin is commonly thought to be a hybrid of the lemon and the Seville orange.
It is an old species that was already described in the 17th century by the Sienese Jesuit monk and keen botanist Giovanni Battista Ferrari (c.1584–1655) in his treatise on citrus fruit entitled Hesperides, sive de malorum aureorum cultura et usu libri IV (1646).
It is a vigorous plant, more rustic than the lemon, with assurgent branches and small-medium dark green leaves. The new shoots and flowers are slightly purplish, and the fruit is medium-sized and spherical, turning bright orange when ripe. The acidic juice is similar to that of the lemon.
Acid and faintly bitter with a pleasant fragrance and flavor, the Volkamer Lemon has been known for more than 3 centuries. Since the 1950s, the Volkamer has been used in Italy as a rootstock for more commercial lemon varieties. The fruit itself is quite similar to the rough Lemon or Italian Monachello.