Maclura pomifera, commonly known as the Osage orange ( ), is a small deciduous tree or large shrub, native to the south-central United States. It is a member of the mulberry family, Moraceae. It typically grows about tall. The distinctive multiple fruit resembles an immature orange, is roughly spherical, bumpy, in diameter, and turns bright yellow-green in the fall. The fruit excretes a sticky white latex when cut or damaged. Despite the name "Osage orange", it is not related to the orange.

Due to its latex secretions and woody pulp, the fruit is not usually eaten by humans and rarely by foraging animals.

Maclura pomifera has many common names, including mock orange, horse apple, and hedge apple.

History

The earliest account of the tree in the English language was given by William Dunbar, a Scottish explorer, in his narrative of a journey made in 1804 from St. Catherine's Landing on the Mississippi River to the Ouachita River. By providing a barrier that was "horse-high, bull-strong, and pig-tight", Osage orange hedges provided the "crucial stop-gap measure for westward expansion until the introduction of barbed wire a few decades later".

The trees were named ("bow-wood") The trees are also known as "bodark", "bodarc", or "bodock" trees, most likely originating as a corruption of . They liked the wood because it was strong, flexible, and durable, The wood is heavy, hard, strong, and flexible, capable of receiving a fine polish and very durable in contact with the ground. The seeds are oblong. Although the flowering is dioecious, the pistillate tree when isolated will still bear large oranges, visually perfect, but lacking the seeds. The fruit has a slightly cucumber-like flavor. It has since become widely naturalized in the United States and Ontario, Canada. Another historic tree is located on the grounds of Fort Harrod, a Kentucky pioneer settlement in Harrodsburg, Kentucky.

The tree was transferred and planted in many parks in Europe. It is found in Bulgaria and Serbia.

Ecological aspects of historical distribution

thumb|Evidence of a seed predator (February in Kansas).thumb|Mound of a single fallen fruit sprouting seeds (April in Illinois)

Because of the limited original range and lack of obvious effective means of propagation, the Osage orange has been the subject of controversial claims by some authors to be an evolutionary anachronism, whereby one or more now extinct Pleistocene megafauna, such as ground sloths, mammoths, mastodons, or gomphotheres, fed on the fruit and aided in seed dispersal. An equine species that became extinct at the same time also has been suggested as the plant's original dispersal agent because modern horses and other livestock sometimes eat the fruit. while a 2018 study concludes that squirrels are ineffective, short-distance seed dispersers. because it is mostly inedible due to its large size (about the diameter of a softball) and hard, dry texture. Large animals such as livestock, which typically would consume fruits and disperse seeds, mainly ignore the fruit. Loggerhead shrikes, a declining species in much of North America, use the tree for nesting and cache prey items upon its thorns.

Cultivation

Maclura pomifera prefers a deep and fertile soil, but is hardy over most of the contiguous United States, where it is used as a hedge. It must be regularly pruned to keep it in bounds, and the shoots of a single year will grow long, making it suitable for coppicing. A neglected hedge will become fruit-bearing. It is remarkably free from insect predators and fungal diseases.

Chemistry

Osajin and pomiferin are isoflavones present in the wood and fruit in a roughly 1:2 ratio by weight, and in turn comprise 4–6% of the weight of dry fruit and wood samples. Primary components of fresh fruit include pectin (46%), resin (17%), fat (5%), and sugar (before hydrolysis, 5%). The moisture content of fresh fruits is about 80%.

Uses

thumb|upright|A tree [[felling|felled in 1954 exhibits little rot after more than six decades.]]

thumb|upright| Typical bright-yellow newly cut wood

The Osage orange is commonly used as a tree row windbreak in prairie states, which gives it one of its colloquial names, "hedge apple". The sharp-thorned trees were also planted as cattle-deterring hedges before the introduction of barbed wire, and afterward became an important source of fence posts. In 2001, its wood was used in the construction in Chestertown, Maryland, of the schooner Sultana, a replica of .

The heavy, close-grained, yellow-orange wood is dense and prized for tool handles, treenails, fence posts, and other applications requiring a strong, dimensionally stable wood that withstands rot. Although its wood is commonly knotty and twisted, straight-grained Osage orange timber makes good bows, as used by Native Americans.

Osage orange wood is more rot-resistant than most, making good fence posts. Its dense grain structure makes for good tonal properties. Production of woodwind instruments and waterfowl game calls are common uses for the wood.

Compounds extracted from the fruit, when concentrated, may repel insects, but the naturally occurring concentrations of these compounds in the fruit are too low to make the fruit an effective insect repellent. In 2004, the EPA insisted that a website selling M. pomifera fruits online remove any mention of their supposed repellent properties as false advertising.

Traditional medicine

The Comanche formerly used a decoction of the roots topically as a wash to treat sore eyes.

References

  • Maclura pomifera images at bioimages.vanderbilt.edu