Family: Moraceae
Morus rubra (red mulberry) is a deciduous tree native to eastern and central North America. When the first English colonizers explored eastern Virginia in 1607, they observed an abundance of mulberry trees and noted that the fruits were consumed, sometimes boiled, by the native Powhatan tribes. Today, mulberries are enjoyed fresh, in pastries, and as wine. They are also used in marmalades, liquors, natural dyes, and cosmetics. Native American tribes used bark infusions as laxatives, while root infusions addressed weakness and urinary issues, and sap treated ringworm. The Choctaw people even wove clothing from the inner bark. While potentially naturalizing beyond its native range, there is no documentation of red mulberry being naturalized on any Hawaiian Islands so far. The berries attract birds, aiding seed dispersal, and the tree’s shade tolerance, dense thickets, and highly allergenic pollen contribute to its weediness.
High Risk Traits:
- Broad climate suitability and range
- Range extends into subtropical regions
- Possibly naturalizing outside native range
- Described as a weedy, self-seeder
- Other Morus species are invasive
- Potentially allelopathic
- Pollen from male trees reported to be a severe allergen
- Shade tolerant (although dense shade may inhibit spread)
- Tolerates many soil types
- May form dense thickets (reported from native range)
- Reproduces by seeds and root suckers
- Hybridizes with Morus alba
- Seeds dispersed by birds and intentionally by people
- Tolerates and resprouts after heavy pruning, but reportedly killed by fires
Low Risk Traits:
- Unarmed (no spines, thorns, or burrs)
- Palatable to browsing animals
- Dioecious trees not self-compatible, but some trees reported to be monoecious
- Minimum seed-bearing age is usually about 10 years
- Herbicides may provide effective control if needed