WHORTLEBERRY, a vernacular name corrupted from the Latin myrtillus, under which appellation, according to Prior, the berries of the common myrtle were employed in the Middle Ages for culinary purposes. In more modern times the term has been applied to various species of Vaccinium, particularly to V. Myrtillus, also known as the bilberry. The berries of this plant have a considerable similarity to those of the myrtle. Several species of Vacciniurn occur on moorlands throughout the northern hemisphere. They are low shrubs allied to heaths, usually with evergreen leaves and with small bell-shaped or urn-shaped flowers, which have an inferior ovary surmounted by five calyx lobes. The stamens, though in a single row, are double the number of the corolla lobes. The anthers have usually two horns at the back and are generally prolonged at the top into two longish tubes, each with a hole at the extremity, through which the pollen escapes. The fruit is a globular or ovoid, many-seeded berry. I'. Jfyrtillus and V. uliginosuna have blue berries ; V. Vitis ithca, the cowberry, has red fruits. A hybrid between V. Hyrtillus and V. Vitis idtra, called IT intermedium, occurs in Shropshire and Staffordshire. The cranberry (Oxycoccus) is very closely allied to the whortleberry.