Ligustrum spp. are deciduous, semi-evergreen, or evergreen shrubs and small trees in the Oleaceae (olive family). There are approximately 50 Ligustrum species that are native to Europe, North Africa, and Asia. Ligustrum spp. have been cultivated and developed into several horticultural varieties, and were introduced to North America as a common hedge in landscaping. Some Ligustrum spp. can grow to 5 m tall and have a stem diameter of 2.5-25 cm. Ligustrum spp. bark is whitish-tan to gray in color and smooth in texture. Slender twigs are straight, rounded or four-angled below the nodes, and gray-green in color. Winter buds are ovoid with two outer scales. Terminal buds are present.
Foliage
The simple leaves are elliptic to ovate in shape, oppositely arranged on slender twigs, often leathery and thick. The leaf margins are smooth and entire.
Flowers
Flowers have both male and female parts, and the corollas are white. The calyx is small, obconic or campanulate, and 4-toothed. Each flower has petals that are fused into a tube below with four separate lobes above. Flowers are borne on small panicles terminating the main axis and on short lateral branches. Bloom time is usually June-July.
Fruit
The fruit is a subglobose or ovoid drupe containing 1-4 seeds. Fruit clusters generally ripen during September and October and persist through the winter. Mature specimens can produce hundreds of fruit.
Ecological Threat
Ligustrum spp. can easily escape cultivation to invade adjacent areas and can form dense monospecific thickets. Several Ligustrum species have become common invaders of cultivated landscapes, disturbed areas and wildlands throughout the U.S.