Morus rubra, commonly known as the red mulberry, is a species of mulberry native to eastern and central North America. It is found from Ontario, Minnesota, and Vermont south to southern Florida, and west as far as southeastern South Dakota, Nebraska, Kansas, and central Texas. There have been reports of isolated populations (very likely naturalized) in New Mexico, Idaho, and British Columbia.
Red mulberry is a deciduous tree, growing to 10–15 m (35–50 ft) tall, rarely 20 m (65 ft), with a trunk up to 50 cm (20 in) in diameter. It is a small to medium-sized tree that reaches a height of 70 feet and lives up to 125 years.
The leaves are alternate, 7–18 cm (2 3⁄4–7 in) long (rarely to 36 cm or 14 1⁄4 in) and 8–12 cm (3 1⁄4–4 3⁄4 in) broad (about twice as big as the white mulberry's leaves), simple, broadly cordate, with a shallow notch at the base, typically unlobed on mature trees although often with 2-3 lobes, particularly on young trees, and with a finely serrated margin. Unlike the leaves of white mulberry (M. alba) which have a lustrous upper surface, the red mulberry leaf upper surface is noticeably rough, similar in texture to fine sandpaper, and the underside is densely covered with soft hairs. The leaf petiole exudes milky sap when severed. The leaves turn yellow in Autumn. Red mulberry is hardy to subzero temperatures, relatively hardy to drought, pollution, and poor soil, though the white mulberry is hardier.
The flowers are relatively inconspicuous: small, yellowish green or reddish green and opening as leaves emerge. Male and female flowers are usually on separate trees although they may occur on the same tree.
The fruit is a compound cluster of several small achenes surrounded by a fleshy calyx, similar in appearance to a blackberry, 2–3 cm (3⁄4–1 1⁄4 in) long. It is initially pale green, ripening to red or dark purple. The berries are widely sought after by birds in spring and early summer in North America; as many as 31 species of birds have been recorded visiting a fruiting tree in Arkansas.
The berries are edible and very sweet. The first English colonists to explore eastern Virginia in 1607 mentioned the abundance of both mulberry trees and their fruit, which was eaten (sometimes boiled) by the native Powhatan tribes. Today, mulberries are eaten raw, used in the fillings of pastries, and fermented into wine.
- Duhamel du Monceau, H.L., Traité des arbres et arbustes, Nouvelle édition [Nouveau Duhamel], vol. 4: t. 23 (1809) [P.J. Redouté] drawing: P.J. Redouté lithograph Tassaert family: Moraceae subfamily: Moroideae tribe: Moreae 202746 ruber, rubra, rubrum 202746 ruber, rubra, rubrum Illustration contributed by: Real Jardín Botánico, Madrid, Spain
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- M. P. Nepal* and D. J. Wichern, "Taxonomic Status Of Red Mulberry (Morus Rubra, Moraceae) At Its Northwestern Boundary", Proceedings of the South Dakota Academy of Science, Vol. 92 (2013), p. 19 ff., http://sdaos.org/wp-content/uploads/pdfs/2013/19-29.pdf, accessed July 2019
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- Jackson, J. L. and R. Kannan. 2018. Avian frugivory in a fruiting mulberry tree (Morus rubra) in Arkansas. J. Arkansas Acad. Sci. 72:38-46. |https://scholarworks.uark.edu/cgi/viewcontent.cgi?article=3310&context=jaas
- Little, Elbert L. (1994) . The Audubon Society Field Guide to North American Trees: Western Region (Chanticleer Press ed.). Knopf. p. 426. ISBN 0394507614.