Polygala vulgaris, known as the Common Milkwort, is a herbaceous perennial plant of the genus Polygala belonging to the Polygalaceae family. The biological form of Polygala vulgaris is hemicryptophyte scapose, as its overwintering buds are situated just below the soil surface and the floral axis is more or less erect with a few leaves. Polygala vulgaris reaches on average 735 centimetres (2.814 in) in height. The stems have many branches and are woody at the base. It has alternating pointed leaves, almost glabrous, 2 to 4 mm wide and 10 to 20 mm long. Basal leaves are spatulate, with rounded apex, while the upper leaves are lanceolate. The flowers are gathered in long terminal inflorescences. The color of the corolla varies between blue and violet, it can rarely occurs purple forms. The flower's outer three sepals are normally small, green and insignificant, while the inner two sepals are bigger. The inner sepals are usually shorter than the petals.