Osage-orange, Horse-apple, Bois D'Arc, or Bodark (Maclura pomifera) is a small deciduous tree or large shrub, typically growing to tall. It is dioeceous, with male and female flowers on different plants. The fruit, a multiple fruit, 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. It is not closely related to the citrus fruit called an orange: Maclura belongs to the mulberry family, Moraceae, while oranges belong to the family Rutaceae.
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.
Osajin and Pomiferin are flavonoid pigments present in the wood and fruit, comprising about 10% of the fruit's dry weight. The plant also contains the flavonol morin.
Recent research suggests that elemol, another component extractable from the fruit, shows promise as a mosquito repellent with similar activity to DEET in contact and residual repellency.
Description
The trees range from high with short trunk and round-topped head. The juice is milky and acrid. The roots are thick, fleshy, covered with bright orange bark.
The leaves are arranged alternately on a slender growing shoot long, varying from dark to pale tender green. 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 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 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 slightest wounding of the surface. Although the flowering is diœcious, the pistillate tree even when isolated will bear large oranges, perfect to the sight but 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. It has a specific gravity of 0.7736 and of the wood has a weight of .
Winter buds: All buds lateral. Depressed-globular, partly immersed in the bark, pale chestnut brown.
Leaves: Alternate, simple, long, 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, in diameter, made up of numerous small
drupes, crowded and grown together. These small drupes are oblong, compressed, rounded, often notched at the apex. They are filled with milky, latex-based juice. The seeds are oblong. The fruit is often seedless, and floats.
Distribution
Osage-orange occurred historically in the
Red River drainage of
Oklahoma,
Texas, and
Arkansas and in the
Blackland Prairies,
Post Oak Savannas, and
Chisos Mountains of Texas. It has been widely naturalized in the United States and Ontario, as well as being occasionally planted.
Ecological aspects
The fruit has a pleasant and mild odor, but is inedible for the most part. Although it is not strongly poisonous, eating it may cause vomiting. However, the seeds of the fruit are edible. The fruit is 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 fruit serves the function of
seed dispersal by means of its 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, such as 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 agent 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 over most of the contiguous United States, 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 long. A neglected hedge will soon become fruit-bearing. It is remarkably free from insect enemies and fungal diseases. 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.
The heavy, close-grained yellow-orange wood is very dense and is prized for tool handles, treenails, 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.
Today, the fruit is sometimes used to deter spiders, cockroaches, boxelder bugs, crickets, fleas, and other arthropods. 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.
History
The earliest account of the tree 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. 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"). It was popular with them because it is strong, flexible and durable. This tree was common along river bottoms of the
Comanchería.
References
External links
Facts and Myths Associated with "Hedge Apples" from an Iowa State University website
Maclura pomifera images at bioimages.vanderbilt.edu
Maclura pomifera (Rafinesque) Nuttall
Flora of North America. Maclura pomifera
Osage Orange information and wood
pomifera
Category:Trees of Michigan
Category:Trees of the United States
Category:Trees of Texas
