Ponderosa lemon
The ponderosa lemon originated in roughly 1887, and is believed to come from a chance seedling grown in Hagerstown, Maryland. It was later named and introduced to the nursery trade in 1900. Though often referred to as a cross between the lemon and citron, a recent genomic analysis showed it to solely contain pomelo ("Citrus maxima") and citron ("Citrus medica") DNA, perhaps being an F2 hybrid. Thus they cannot derive from true lemons, which have a mandarin orange component.
Gin and tonic
Gin and tonic is traditionally garnished with a slice or wedge of lime, often slightly squeezed into the drink before being placed in the glass. In most parts of the world lime remains the only usual garnish; however, in the United Kingdom it has become common to use lemon as an alternative fruit; use of both fruit together is known as an "Evans". Although the origins of the use of lemons are unknown, their use dates back at least as far as the late 1930s. In addition lemons are often more readily available, and cheaper to purchase, than limes. The use of lemon or lime is a debated issue - some leading brands, such as Gordon's, Tanqueray, and Bombay Sapphire, recommend the use of lime in their gin.