Rambo is the name of two apple varieties.
The origins of the Rambo may date back to the American colony of New Sweden, when in 1637 Peter Gunnarsson Rambo, a Swedish immigrant, arrived on the Kalmar Nyckel. In "Addenda to the Diary," published with the 1963 edition of Peter Kalm's Travels in North America, 1747-51, the editor includes notes of Kalm's interview with Mr. Peter Rambo, grandson of Peter Gunnarsson Rambo, where it is stated that the original Peter Rambo, when he emigrated, had brought apple seeds and several other tree and garden seeds with him in a box. The first Rambo apple tree may have been produced from one of these seeds, or could have been developed by one of his descendants. There is no certainty, since the earliest documented mention of the apple variety's origin occurs in William Coxe's A View of the Cultivation of Fruit Trees, and the Management of Orchards and Cider, published in 1817. Coxe wrote only that the Rambo was much cultivated in Delaware, Pennsylvania, and New Jersey and took "its name from the families by whom it was introduced into notice." Since apple trees do not grow true from seed, and Rambo brought seeds, not scionwood, if the first Rambo tree grew from one of those seeds, the variety would be one of the first truly American apples.
The greenish yellow apple with dull red stripes ripens from mid-summer to early fall. Little known today, the Rambo was once widely grown, but in a limited geographical range from the mid-Atlantic states west into the middle Prairie states. The apple was beloved for its distinctive flavor and aroma, as well as its versatility. The apple has been rated very good to excellent for fresh eating, cooking and baking, jelly, and drying. In Varieties of Apples in Ohio (1915), the "little old-fashioned Rambo" was said to have been found "in almost every old orchard in Ohio." The Rambo belongs to the era when people bought apples from local suppliers and grew apple trees in their backyard. Even a hundred years ago, the Rambo was not widely grown commercially. It was considered to be too small and not red enough to be marketable. In addition, its productivity was inconsistent; it did not have a long storage life; and it was too tender for shipping long distances.
The name Rambo was most likely derived from Peter Gunnarsson's Swedish home on Ramberget (or "Raven Mountain") on the island of Hisingen, which today is part of Gothenburg, but in Gunnarsson's time was mostly farmland. One translation of "bo" from Swedish to English is "resident."
So as not to confuse the Rambo apple with the unrelated Summer Rambo, the Rambo has also been called the Winter Rambo. Other names given to the Rambo over the years include Romanite, Bread and Cheese (perhaps after Bread and Cheese Island in Delaware), Seek-No-Further, Delaware, and Striped Rambo.
Summer Rambo 
The Summer Rambo is French in origin and, like the Rambo, was introduced to North America in colonial times. In North America, the apple was first called Summer Rambour and Rambour Franc. In France, where there are a dozen or more Rambour varieties, it is known as Rambour d'Ete. The name Rambour is said to have originated in the village of Rambure in Picardy. The name of the apple evolved from Summer Rambour to Summer Rambo sometime before the 1850s.
The Summer Rambo has a squat shape, and its skin is greenish-yellow flushed or blushed with red, making it confusingly similar to the Rambo.
The Summer Rambo has a crisp, mildly tart flavor. As is the case with most summer apples, the Summer Rambo is not a keeper, and because of that never became widely produced commercially. It still is popular in parts of the country in early August at pick-your-own orchards, farmers markets, and roadside stands.
In popular culture 
According to author David Morrell, the apple provided the name for the hero of his novel, First Blood, which gave rise to the Rambo film franchise. The novelist's wife brought home a supply of the fruit as he was trying to come up with a suitable name for the protagonist.
James Whitcomb Riley, the Hoosier Poet, sentimentalized the Rambo in his poem, The Rambo-Tree which appeared in his 1902 collection The Book of Joyous Children. The poem includes the repeating chorus:
For just two truant lads like we,
When Autumn shakes the rambo-tree
There's enough for you and enough for me
It's a long, sweet way across the orchard.
A similar sentiment was expressed by "Uncle Silas" in his column for the September 1907 issue of The American Thresherman: "What has become of the good old apples we used to eat in the long ago down on the farm? The Rambo, the best apple that ever grew in an orchard, is fruit vouchsafed only in memory. [In Missouri,] no apple was ever enjoyed like the Rambo.... A boy would go farther to swipe Rambo apples, and subject his pantaloons to greater exposure from ugly dogs than he would for any other kind, and boys know on which tree the best apples grow. A drink of cider without any fixin', made of Rambo apples, will go farther down and awake the molecules of mankind in a greater degree than any other kind of cider. The world is growing wiser, but not in raising Rambo apples."
A story that has been perpetuated that the Rambo was the favorite apple of Johnny Appleseed is false. Johnny Appleseed did not grow or sell any grafted varieties, and for the Rambo or any other variety to be perpetuated, it must be grafted. As Michael Pollan indicates in his chapter on the apple in Botany of Desire, John Chapman (1774–1845), for religious reasons related to the doctrines of Emanuel Swedenborg, believed grafting was an unnatural practice. Chapman was given the nickname "Appleseed" pejoratively for his highly unusual practice of planting trees from seed. The apples grown from seed are almost all small and poorly flavored, so with very rare exceptions, his trees would have been good for making hard cider only. Back when the frontier only extended as far west as the state of Indiana, that worked fine for Johnny Appleseed, since cider was a staple and the pioneers didn't have any other choice in suppliers. The apple tree in Nova, Ohio, that is more than 175 years old, can either be the last surviving apple tree that Johnny Appleseed planted or it can be a Rambo tree. It cannot be both, despite any marketing claims.
- http://books.google.com/books?id=O-gCAAAAYAAJ Apples of New York
- http://books.google.com/books?id=1rMzAQAAIAAJ The Book of Joyous Children.
- Beach, Spencer Ambrose. Apples of New York., 2vols, J.B. Lyon, 1905.
- Coxe, William. A view of the cultivation of fruit trees, and the management of orchards and cider., 253pp, M. Carey and Son, 1817.
- Kalm, Pehr, 1716-1779. Peter Kalm's travels in North America; the America of 1750; the English version of 1770, rev. from the original Swedish and edited by Adolph B. Benson, with a translation of new material from Kalm's diary notes., 797pp, Dover, 1966. NOTE: "The hitherto untranslated portion has been done into English by Miss Edith M. L. Carlborg and the present editor."