White Mulberry (Morus alba)

Native to India and central China, this rapidly spreading mulberry tree was introduced across the Americas, Australia, West Asia, and Europe during the early colonial era to feed silkmoth caterpillars. It remains widely cultivated for this purpose, as these caterpillars are bred to produce silk. Moreover, it produces irregularly toothed leaves and small, juicy, red to purple fruits that resemble blackberries in form, though they are not as sweet. The seeds are widely spread by birds who eat this fruit; thus, it has naturalized in many of these places, particularly thriving in mildly acidic, well-drained soils in temperate regions. 

Though fast-growing, white mulberry is small-sized, growing between 30 – 65 feet, and short-lived, usually surviving less than 100 years. Yet, it can readily tolerate poor soils, allowing it to take over anthropogenically disturbed habitats, such as roadsides and old fields. It is now known to displace native species and hybridize with the red mulberry, a native to eastern North America with which it shares a resemblance. In fact, the genetic viability of the red mulberry may be waning as more and more succumb to hybridization with the non-native species. Though it has not yet been reviewed by the Massachusetts Invasive Plant Advisory Group, it has been documented as invasive in other eastern US states.