(Britannica.com): “A number of species and varieties of orange are economically important, namely the China orange, also called the sweet, or common, orange (Citrus ×sinensis); the mandarin orange (C. reticulata), some varieties of which are called tangerines; and the sour, or Seville, orange (C. ×aurantium), which is less extensively grown. Common varieties of the sweet orange include the Jaffa, from Israel, the seedless navel, and the Maltese, or blood, orange.”
“Eleanor Gwyn (2 February 1650 – 14 November 1687; also spelled Gwynn, Gwynne) was a prolific celebrity figure of the Restoration period. Praised by Samuel Pepys for her comic performances as one of the first actresses on the English stage, she became best known for being a long-time mistress of King Charles II of England and Scotland. Called “pretty, witty Nell” by Pepys, she has been regarded as a living embodiment of the spirit of Restoration England and has come to be considered a folk heroine, with a story echoing the rags-to-royalty tale of Cinderella. Gwyn had two sons by King Charles: Charles Beauclerk (1670–1726) and James Beauclerk (1671–1680) (the surname is pronounced boh-clair). Charles was created Earl of Burford and later Duke of St. Albans…
…In 1663 the King’s Company, led by Thomas Killigrew, opened a new playhouse, the Theatre in Bridges/Brydges Street, which was later rebuilt and renamed the Theatre Royal, Drury Lane.
Mary Meggs, a former prostitute nicknamed “Orange Moll” and a friend of Madam Gwyn’s, had been granted the licence to “vend, utter and sell oranges, lemons, fruit, sweetmeats and all manner of fruiterers and confectioners wares,” within the theatre. Orange Moll hired Nell (Gwyn) and her older sister Rose as scantily clad “orange-girls”, selling the small, sweet “china” oranges to the audience inside the theatre for a sixpence each. The work exposed her to multiple aspects of theatre life and to London’s higher society: this was after all “the King’s playhouse”, and Charles frequently attended performances. The orange-girls would also serve as messengers between men in the audience and actresses backstage; they received monetary tips for this role and some of these messages would end in sexual assignations…”
Pascal Tréguer writes at wordhistories.net:
“The term China orange denotes the sweet orange, the fruit of Citrus sinensis, originally brought from China. In Food: An Authoritative and Visual History and Dictionary of the Foods of the World (1996 edition), the American journalist and author Waverley Root (1903-82) wrote the following about oranges:
They were rare in early Tudor England but a trifle more familiar by Elizabeth’s time. […] By the time of Charles II the fruit was so common that “orange girls” sold it in theaters, and, at a slightly higher price, themselves.
Therefore, China orange came to be frequently used figuratively to mean anything of minimal value…
Lombard Street in London—so called because originally occupied by Lombard bankers—still contains many of the principal London banks. (Rue des Lombards in Paris has the same origin.)
The phrase therefore expresses a fanciful bet wagering the wealth that is available in the street’s banks against something of trifling value. In its earliest known occurrence, from The Citizen (London, 1763), a farce by the Irish playwright and actor Arthur Murphy (1727-1805), the comparison is between all Lombard Street and an eggshell…”