John McPhee's 1967 book Oranges is fascinating.
The taste and aroma of oranges differ by type, season, country, state, and country, and even as a result of the position of the individual orange in the framework of the tree on which it grew. Ground fruit -- the orange that one can reach and pick from the ground -- is not as sweet as fruit that grows high on the tree. Outside fruit is sweeter than inside fruit. Oranges grown on the south side of a tree are sweeter than oranges grown on the east or west sides, and oranges grown on the north side are the least sweet of the lot. The quantity of juice in an orange, and even the amount of Vitamin C it contains, will follow the same pattern of variation. Beyond this, there are differentiations of quality inside a single orange. Individual segments vary from one to another in their content of acid and sugar. But that is cutting it pretty fine. Orange men, the ones who actually work in the groves, don't discriminate to that extent. When they eat an orange, they snap out the long, thin blades of their fruit knives and peel it down, halfway, from the blossom end, which is always sweeter and juicier than the stem end. They eat the blossom half and throw the rest of the orange away.
The color of an orange has no absolute correlation with the maturity of the flesh and juice inside. An orange can be as sweet and ripe as it will ever be and still glisten like an emerald in the tree. Cold -- coolness, rather -- is what makes an orange orange. In some parts of the world, the weather never gets cold enough to change the color; in Thailand, for example, an orange is a green fruit, and traveling Thais often blink with wonder at the sight of oranges the color of flame. The ideal nighttime temperature in an orange grove is forty degrees. Some of the most beautiful oranges in the world are grown in Bermuda, where the temperature, night after night, falls consistently to that level. Andrew Marvell's poem wherein the "remote Bermudas ride in the ocean's bosom unespied" was written in the sixteen-fifties, and contains a description, from hearsay, of Bermuda's remarkable oranges, set against their dark foliage like "golden lamps in a green night."
Some oranges that become orange while they are still unripe may turn green again as they ripen. When cool nights finally come to Florida, around the first of the year, the Valencia crop is fully developed in size and shape, but it is still three months away from ripeness. Sliced through the middle at that time, a Valencia looks something like a partitioned cupful of rice, and its taste is overpoweringly acid. But in the winter coolness, the exterior surface turns to bright orange, and the Valencia appears to be perfect for picking. Warm nights return, however, during the time of the Valencia harvest. On the trees in late spring, the Valencias turn green again, growing sweeter each day and greener each night.
Oranges and orange blossoms have long been symbols of love. Boccoccio's Decameron, written in the fourteenth century, is redolent with the scent of oranges and orange blossoms, with lovers who wash in orange-flower water, a courtesan who sprinkles her sheets with orange perfume, and the mournful Isabella, who cuts off the head of her dead lover, buries it in an ample pot, plants sweet basil above it, and irrigates the herbs exclusively with rosewater, orange-flower water, and tears. In the fifteenth century, the Countess Mathilda of Württemberg received from her impassioned admirer, Dr. Heinrich Steinbowel, a declaration of love in the form of a gift of two dozen oranges. Before long, titled German girls were throwing oranges down from their balconies in the way that girls in Italy or Spain were dropping handkerchiefs. After Francis I dramatically saved Marseilles from a Spanish siege, a great feast was held for him at the city's harborside, and Marseillaise ladies, in token of their love and gratitude, pelted him with oranges. Even Nostradamus was sufficiently impressed with the sensual power of oranges to publish, in 1556, a book on how to prepare various cosmetics from oranges and orange blossoms. Limes were also used cosmetically, by ladies of the French court in the seventeenth century, who kept them on their persons and bit into them from time to time in order to redden their lips. In the nineteenth century, orange blossoms were regularly shipped to Paris in salted barrels from Provence, for no French bride wanted to be married without wearing or holding them.
Paradoxically, many societies have believed that the worst thing that could happen to an orange tree was the touch of a woman. If a woman were even to go near one, some thought, the foliage would wilt and fall away, the fruit would drop, and the tree would die. A Spanish Moor of the twelfth century, whose name was Abu Zakariya Yahya Ibn el-Awwam, wrote a basic text called The Book of Agriculture, which contained material on citriculture that was remarkably accurate and complete, until he brought up the matter of women. "Women should not be allowed to come near citrus trees," he wrote, "unless they are in a state of absolute purity and unimpaired health." According to the same writer, however, the woman stood to gain much from the very tree she was capable of destroying. "If a woman eats an orange," he added, "it will banish all evil thoughts from her mind."