Maclura pomifera

Osage-orange
Osage-orange foliage and fruit
Scientific classification
Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Magnoliopsida
Order:	Rosales
Family:	Moraceae
Genus:	Maclura
Species:	M. pomifera
Binomial name
Maclura pomifera (Raf.) Schneid.

The Osage-orange (Maclura pomifera) is a plant in the mulberry family Moraceae. It is also known as Osage-apple, mock orange, hedge-apple, horse-apple, hedge ball, bois d'arc, bodark (mainly in Oklahoma and Texas), and bow wood. Common slang terms for it include monkey brain, monkey ball, monkey orange, and brain fruit due to its brainlike appearance.

The species is dioeceous, with male and female flowers on different plants. It is a small deciduous tree or large shrub, typically growing to 8-15 m tall. The fruit, a syncarp of achenes, is roughly spherical, but bumpy, and 7-15 cm in diameter, and it is filled with a sticky white latex sap. In fall, its color turns a bright yellow-green and it has a faint odor similar to that of oranges.

Maclura is closely related to the genus Cudrania, and hybrids between the two genera have been produced. In fact, some botanists recognize a more broadly defined Maclura that includes species previously included in Cudrania and other genera of Moraceae.

Recent research suggests that elemol, one of the major components of oil extracted from fruit of Osage orange, shows promise as a mosquito repellent with similar activity to DEET in contact and residual repellency.

Description

Forty to sixty feet high with short trunk and handsome round-topped head. Juice milky and acrid. Roots thick, fleshy, covered with bright orange colored bark.

The leaves are beautiful singly, but arranged alternately on a slender growing shoot three or four feet long, varying from dark to pale tender green, every one glistening and glittering in the sunlight, they are indeed beautiful. In form they are very simple, a long oval terminating in a slender point. In the axil of every growing leaf is found a growing spine which when mature is about an inch long, and rather formidable. The pistillate and staminate flowers are on different trees; both are inconspicuous; but the fruit is very much in evidence. This in size and general appearance resembles a large, yellow green orange, only its surface is roughened and tuberculated. It is, in fact, a compound fruit such as the botanists call a syncarp, where the carpels, that is, the ovaries have grown together and that the great orange-like ball is not one fruit but many. it is heavily charged with milky juice which oozes out at the slighest wounding of the surface. Although the flowering is diœcious, the pistillate tree even when isolated will bear large oranges, perfect to the sight buth lacking the seeds.

• Bark: Dark, deeply furrowed, scaly. Branchlets at first bright green, pubescent, during first winter they become light brown tinged with orange, later they become a paler orange brown. Branches with yellow pith, and armed with stout, straight, axillary spines.
• Wood: Bright orange yellow, sapwood paler yellow; heavy, hard, strong, flexible, capable of receiving a fine polish, very durable in contact with the ground. Sp. gr., 0.7736; weight of cu. ft., 48.21 lbs.
• Winter buds: All buds lateral. Depressed-globular, partly immersed in the bark, pale chestnut brown.
• Leaves: Alternate, simple, three to five inches long, two to three inches wide, ovate to oblong-lanceolate, entire, acuminate, or acute or cuspidate, rounded, wedge-shaped or subcordate at base. Feather-veined, midrib prominent. They come out of the bud involute, pale bright green, pubescent and tomentose, when full grown are thick, firm, dark green, shining above, paler green below. In autumn they turn a clear bright yellow. Petioles slender, pubescent, slightly grooved. Stipules small, caducous.
• Flowers: June, when leaves are full grown; diœcious. Staminate flowers in racemes, borne on long, slender, drooping peduncles developed from the axils of crowded leaves on the spur-like branchlets of the previous year. Racemes are short or long. Flowers pale green, small. Calyx hairy, four-lobed. Stamens four, inserted opposite lobes of calyx, on the margin of thin disk; filaments flattened, exserted; anthers oblong, introrse, two-celled; cells opening longitudinally; ovary wanting. Pistillate flowers borne in a dense globose many-flowered head which appears on a short stout peduncle, axillary on shoots of the year. Calyx, hairy, four-lobed; lobes thick, concave, investing the ovary, and inclosing the fruit. Ovary superior, ovate, compressed, green, crowned by a long slender style covered with white stigmatic hairs. Ovule solitary.
• Fruit: Pale green globe, four to five inches in diameter, made up of numerous small drupes, crowded and grown together. These small drupes are oblong, compressed, rounded, often notched at apex, filled with milky juice. Seed oblong, the fruit is often seedless.

Distribution

Native to the rich bottom lands of Arkansas, Texas, and Oklahoma. It has been widely naturalized throughout the U.S. and Canada.

Ecological aspects

Osage-orange fruit

The fruits have a pleasant and mild odor, but are inedible for the most part. Although not strongly poisonous, eating it may cause vomiting. The fruits are sometimes torn apart by squirrels to get at the seeds, but few other native animals make use of it as a food source. This is unusual, as most large fleshy fruits serve the function of seed dispersal, accomplished by their consumption by large animals. One recent hypothesis is that the Osage-orange fruit was eaten by a giant ground sloth that became extinct shortly after the first human settlement of North America. Other extinct Pleistocene megafauna, like the mammoth, mastodon and gomphothere may have fed on the fruit and aided in seed dispersal. An equine species that went extinct at the same time also has been suggested as the plant's original dispersal mechanism because modern horses and other livestock will sometimes eat the fruit.

Cultivation

It is native to a deep and fertile soil but it has great powers of adaptation and is hardy throughout the north, where it is extensively used as a hedge plant. It needs severe pruning to keep it in bounds and the shoots of a single year will grow three to six feet long. A neglected hedge will soon become fruit-bearing. It is remarkably free from insect enemies and fungal diseases.

Uses

The sharp-thorned trees were planted as cattle-deterring hedges before the introduction of barbed wire. The fruit is eaten by cattle but is not good for them. The heavy, closely grained yellow-orange wood is very dense and is prized for tool handles, tree nails, fence posts, electrical insulators, and other applications requiring a strong dimensionally-stable wood that withstands rot. Straight-grained osage timber (most is knotty and twisted) makes very good bows. In Arkansas, in the early 19th century, a good osage bow was worth a horse and a blanket. Additionally, a yellow-orange dye can be extracted from the wood, which can be used as a substitute for fustic and aniline dyes. When dried, the wood also makes excellent fire wood that burns long and hot.

Today, the fruit is sometimes used to deter spiders, cockroaches, boxelder bugs, crickets, fleas, and other insects. An article posted by the Burke Museum in Washington State claims that this usage, in the case of spiders, has no evidence to support it.^[2] Unfortunately the article cites no research or studies that test the hypothesis. However, hedge apple oil has been shown to effectively repel cockroaches (University of Iowa, 2004), and the fruit may indeed have an effect of repelling cockroaches and boxelder bugs.

History

The plant is native to an area in the central United States consisting of parts of Kansas, Missouri, Arkansas, southeastern Oklahoma, a narrow belt in eastern Texas, and the extreme northwest corner of Louisiana, but was not common anywhere. The earliers account of the tree was given by a Scottish gentleman, William Dunbar, in his narrative of a journey made in 1804 from St. Catherine's Landing on the Mississippi to the Wishita river. It was a curiosity when Meriwether Lewis sent some slips and cuttings to President Jefferson in March 1804. The samples, donated by "Mr. Peter Choteau, who resided the greater portion of his time for many years with the Osage Nation according to Lewis' letter, didn't take, but later the thorny Osage-orange was widely naturalized throughout the U.S. In 1810, Bradbury relates that he found two trees growing in the garden of Pierre Chouteau, one of the first settlers of St. Louis (apparently "Peter Choteau").

The trees picked up the name bois d'arc, or "bow-wood", because early French settlers observed the wood being used for war clubs and bow-making by Native Americans. The people of the Osage Nation "esteem the wood of this tree for the making of their bows, that they travel many hundred miles in quest of it," Meriwether Lewis was told in 1804.

External links

• Osage-orange factsheet from the United States Forest Service
• Maclura pomifera (Rafinesque) Nuttall
• Facts and Myths Associated with "Hedge Apples" from an Iowa State University website
• Maclura pomifera images at bioimages.vanderbilt.edu
• Anachronistic fruits