The classic and trusted book "Fifty Common Trees of Indiana" by T.E. Shaw was published in 1956 as a user-friendly guide to local species. Nearly 70 years later, the publication has been updated through a joint effort by the Purdue Department of Forestry and Natural Resources, Indiana 4-H, and the Indiana Department of Natural Resources, and reintroduced as "An Introduction to Trees of Indiana."
A printed copy of the full publication is available for purchase for $7 in the Purdue Extension Education Store. The field guide helps identify common Indiana woodlot trees.
Each week, the Intro to Trees of Indiana web series will offer a sneak peek at one species from the book, paired with an ID That Tree video from Purdue Extension forester Lenny Farlee to help visualize each species as it stands in the woods. Threats to species health as well as also insight into the wood provided by the species, will be provided through additional resources as well as the Hardwoods of the Central Midwest exhibit of the Purdue Arboretum, if available.
This week, we introduce the red mulberry or Morus rubra.
Red mulberry has variable leaves, which can come without lobes (entire) or with two (mitten), three or even five lobes. Regardless of shape, the leaves have serrated margins and pointed tips and are arranged alternately on the twigs. The topside of the dark green leaves is sandpapery to the touch and has a matte or flat finish. The dark green leaves turn a golden yellow in the fall.
Basswood has leaves similar to the unlobed variety of red mulberry, but those leaves are smooth to the touch and have finely toothed margins. White mulberry, which is not native to Indiana, also has similar leaves to its cousin red mulberry, but those leaves are typically bright green and smooth, have more rounded teeth on the margins and feature a shinier upper leaf surface.
The bark of red mulberry is gray or brown in color with long flaky ridges, but may show some orange or tan peeking through the fissures in the bark.
The fruit of red mulberry, which hangs individually only the twig, resembles a small blackberry, with a dark purple or almost black color when ripe, that is favored by both birds and humans. Mulberry fruit is typically produced from mid-June to July.
Red mulberry, which is often found under the canopy of other hardwood trees in moist areas such as river bottoms as well as along wooded slopes, wood’s edges and shady roadways, are typically small understory trees, but can grow between 40 and 60 feet tall. Red mulberries are becoming less common on the landscape than the invasive white mulberry, but can be found growing throughout the eastern United States.
The Morton Arboretum warns that red mulberry is susceptible to a variety of pests, including leaf spots, witches brooms, canker diseases, powdery mildew, spider mites and scale insects.
According to the Wood Database, mulberry is rated as very durable and weighs approximately 43 pounds per square foot. It responds well to both hand and machine tooling, and also turns, glues and finishes well. Due to its small size and scattered distribution, mulberry is seldom harvested commercially for lumber. Common uses are fence posts, furniture and turned objects.
Other Resources:
FNR Know Your Tree Series: Red and White Mulberry in Indiana
Morton Arboretum: Red Mulberry
Fifty Trees of the Midwest app for the iPhone, The Education Store
Native Trees of the Midwest, The Education Store
Shrubs and Woody Vines of Indiana and the Midwest, The Education Store
Investing in Indiana Woodlands, The Education Store
Forest Improvement Handbook, The Education Store
ID That Tree, Purdue Extension-Forestry & Natural Resources (FNR) YouTube playlist
Woodland Management Moment , Purdue Extension-FNR YouTube playlist