The cucumber (Cucumis sativus) is the fruit of a creeping vine native to India, where it has been grown since around 1500 BCE and brought to the Mediterranean around a thousand years later. The cucumber is a fruit - it's in the same family as the squash and in the same genus as the muskmelon. 

There are five main varieties of cucumber, which are broadly broken down into slicing types and pickling types. Pickling cucumbers are small and warty, with thin skins that are pale green to green in color. They are typically pickled, either in brine or through a lactic acid fermentation. Smaller versions of these cucumbers are commonly called gherkins, which are actually a related species -- Cucumis anguria. In France, tiny gherkins called cornichons are typically served with pate or charcuterie. Slicing cucumbers, like the typical supermarket cucumber (which is waxed) or the often plastic-wrapped English cucumber (which is not) are typically eaten raw, especially in salads.

Cucumbers have a high water content and a central column of seeds, which are immature and edible. The aroma of cucumber develops when it is chewed or cut, and has a faintly melon-y, watery aldehydic aroma that is cool and clean. The [ingredient=cucumber-peel peel] of most cucumbers has a high concentration of bitter chemicals called cucurbitacins, which discourage pests. 

In cocktail usage, cucumbers offer a refreshing aroma and flavor to drinks. Cucumber is often paired with gin (and in fact, some gins are flavored with cucumber), but interestingly enough, violet pairs very well with cucumber. 

Some popular cocktails containing Cucumber

  • Gin Garden — Gin, Apple juice, Cucumber, Elderflower syrup
  • Cucumber Lavender Sour Punch — Gin, Ginger liqueur, Crème Yvette, Lemon juice, Simple syrup, Cucumber, Lavender Tea
  • The Lady Chesdin — Gin, Dry vermouth, Orange bitters, Peychaud's Bitters, Bitters, Celery bitters, Cucumber, Onion, Sugar cube, Lime
  • Pliny's Tonic — Gin, Lime juice, Simple syrup, Cucumber, chili tincture, Mint
  • Juke Cup — Falernum, Rhum Agricole, Ginger beer, Lime juice, Honey syrup, Cucumber, Pineapple
  • Ma Cherie — Fino sherry, Herbal liqueur, Falernum, Lime juice, Pineapple Gum Syrup, Salt Solution, Celery stalk, Cucumber
  • Us and Them — Rye, Aquavit, Bianco Vermouth, Absinthe, Cucumber
  • Caesarea Cocktail — Gin, Aperol, Simple syrup, Basil, Cucumber, Lemon
  • Veracruz — Tequila, Dry white wine, Lime juice, Aloe vera liqueur, Simple syrup, Hellfire Habanero Shrub, Cucumber
  • Respect your Elderflowers — Gin, Elderflower liqueur, Lemon juice, Simple syrup, Cucumber