Morus alba is a small, 30-50 ft. (9.1-15.2 m) tall, deciduous tree that invades disturbed areas throughout the United States.
Foliage
The alternate leaves are polymorphic (variably shaped), 2-8 in. (5.1-20.3 cm) long and shiny with blunt teeth and heart-shaped bases. Young bark, the bark along the roots, and the inner bark along the trunk are often bright orange in color. Older bark is gray with narrow, irregular fissures.
Flowers
Flowering occurs in April. Plants are normally dioecious (male and female flowers on separate plants). Male flowers are small, green and occur in 1-2 in. (2.5-5.1 cm) long catkins. Female flowers are inconspicuous and crowded in short spikes.
Fruit
Fruits are multiple-seeded berries. They can range in color from black to pink or even white when ripe.
Ecological Threat
Morus alba is very similar to the native red mulberry (Morus rubra), but may be distinguished by the leaves. Morus alba leaves have glossy surfaces whereas the leaves of Morus rubra do not. Morus alba is found throughout the United States, where it invades old fields, urban lots, roadsides, forest edges, and other disturbed areas. It poses an ecological threat by displacing native species, possibly hybridizing with and transmitting a root disease to the native Morus rubra. Morus alba is native to Asia and was introduced in colonial times as a food source for silkworms.