Maclura pomifera
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. Ecologists Daniel H. Janzen and Paul S. Martin proposed in 1982 that the fruit of this species might be an example of what has come to be called an evolutionary anachronism—that is, a fruit coevolved with a large animal seed dispersal partner that is now extinct. This hypothesis is controversial.
Maclura pomifera has many common names, including mock orange, horse apple, hedge apple, hedge ball, monkey ball, pap, monkey brains, and yellow-wood. The name bois d'arc has also been corrupted into bodark and bodock.
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. Meriwether Lewis sent some slips and cuttings of the curiosity to President Thomas Jefferson in March 1804. According to Lewis's letter, the samples were donated by "Mr. Peter Choteau, who resided the greater portion of his time for many years with the Osage Nation". Those cuttings did not survive. In 1810, Bradbury relates that he found two M. pomifera trees growing in the garden of Pierre Chouteau, one of the first settlers of Saint Louis, apparently the same person.American settlers used the Osage orange as a hedge to exclude free-range livestock from vegetable gardens and corn fields. Under severe pruning, the hedge apple sprouted abundant adventitious shoots from its base; as these shoots grew, they became interwoven and formed a dense, thorny barrier hedge. The thorny Osage orange tree was widely naturalized throughout the United States until this usage was superseded by the invention of barbed wire in 1874. 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 bois d'arc by early French settlers who observed the wood being used for war clubs and bow-making by Native Americans. Meriwether Lewis was told that the people of the Osage Nation, "So much... esteem the wood of this tree for the purpose of making their bows, that they travel many hundreds of miles in quest of it." The trees are also known as "bodark", "bodarc", or "bodock" trees, most likely originating as a corruption of bois d'arc.
The Comanche also used this wood for their bows. They liked the wood because it was strong, flexible, and durable, and the bush/tree was common along river bottoms of the Comanchería. Some historians believe that the high value this wood had to Native Americans throughout North America for the making of bows, along with its small natural range, contributed to the great wealth of the Spiroan Mississippian culture that controlled all the land in which these trees grew.
Etymology
The genus Maclura is named in honor of William Maclure, a Scottish-born American geologist. The specific epithet pomifera means "fruit-bearing". The common name "Osage" derives from the Osage people, from whom young plants were first obtained, as told in the notes of Meriwether Lewis in 1804.Description
General habit
Mature trees range from tall with short trunks and round-topped canopies. The roots are thick, fleshy, and covered with bright orange bark. The tree's mature bark is dark, deeply furrowed, and scaly. The plant has significant potential to invade unmanaged habitats.The wood of M. pomifera is golden to bright yellow, but fades to medium brown with ultraviolet light exposure. The wood is heavy, hard, strong, and flexible, capable of receiving a fine polish and very durable in contact with the ground. It has a specific gravity of 0.7736 or.
Leaves and branches
Leaves are arranged alternately in a slender growing shoot long. In form they are simple, a long oval terminating in a slender point. The leaves are long and wide, and are thick, firm, dark green, shining above, and paler green below when full grown. In autumn they turn bright yellow. The leaf axils contain formidable spines, which when mature, are about long.Branchlets are at first bright green and pubescent; during their first winter, they become light brown tinged with orange, and later they become a paler orange-brown. Branches contain a yellow pith, and are armed with stout, straight, axillary spines. During the winter, the branches bear lateral buds that are depressed-globular, partly immersed in the bark, and pale chestnut brown in color.
Flowers and fruit
As a dioecious plant, the inconspicuous pistillate and staminate flowers are found on different trees. Staminate flowers are pale green, small, and arranged in racemes borne on long, slender, drooping peduncles developed from the axils of crowded leaves on the spur-like branchlets of the previous year. They feature a hairy, four-lobed calyx; the four stamens are inserted opposite the lobes of the calyx, on the margin of a thin disk. Pistillate flowers are borne in a dense, spherical, many-flowered head, which appears on a short, stout peduncle from the axils of the current year's growth. Each flower has a hairy, four-lobed calyx with thick, concave lobes that invest the ovary and enclose the fruit. Ovaries are superior, ovate, compressed, green, and crowned by a long slender style covered with white stigmatic hairs. The ovule is solitary.The mature multiple fruit's size and general appearance resembles a large, yellow-green orange, about in diameter, with a roughened and tuberculated surface. The compound fruit is a syncarp of numerous small drupes, in which the carpels have grown together; thus, it is more precisely classified as a multiple-accessory fruit. Each small drupe is oblong, compressed, and rounded; it contains a milky latex that oozes when the fruit is damaged or cut. 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.
Distribution
Osage orange's pre-Columbian range was largely restricted to a small area in what is now the United States, namely the Red River drainage of Oklahoma, Texas, and Arkansas, as well as the Blackland Prairies and post oak savannas. A disjunct population also occurred in the Chisos Mountains of Texas. It has since become widely naturalized in the United States and Ontario, Canada. Osage orange has been planted in all of the 48 contiguous states of the United States and in southeastern Canada.The largest known Osage orange tree is located at the Patrick Henry National Memorial in Brookneal, Virginia, and is believed to be almost 350 years old. 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.
Ecological aspects of historical distribution
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. This hypothesis is controversial. For example, a 2015 study indicated that Osage orange seeds are not effectively spread by extant horse or elephant species, while a 2018 study concludes that squirrels are ineffective, short-distance seed dispersers. The claim has been criticized as a "just-so story" that lacks any empirical evidence.The fruit is not poisonous to humans or livestock, but is not preferred by them, because it is mostly inedible due to a large size and hard, dry texture. The edible seeds of the fruit are used by squirrels as food. Large animals such as livestock, which typically would consume fruits and disperse seeds, mainly ignore the fruit.