Naranjilla Lulo Solanum Quitoense

You never know what you are going to find in downtown Washington, D.C. We found this growing in a collection of American plants next to the National Museum of the American Indian.  It is a Naranjillia or Solanum Quitoense. Here is a more complete explanation from Wikipedia: Solanum quitoense of this South and Central American plant.

Solanum quitoense, known as naranjilla (Spanish pronunciation: [naɾaŋˈxiʎa], "little orange") in Ecuador and Panama and as lulo ([ˈlulo], from Quechua) in Colombia, is a subtropical perennial plant from northwestern South America. The specific name for this species of nightshade means "from Quito." 

The naranjilla plant is attractive, with large elongated heart- or oval-shaped leaves up to 45 cm in length. The leaves and stems of the plant are covered in short purple hairs. Naranjilla are delicate plants and must be protected from strong winds and direct sunlight. They grow best in partial shade. 

The fruit has a citrus flavour, sometimes described as a combination of rhubarb and lime. The juice of the naranjilla is green and is often used as a juice or for a drink called lulada.