From Wikipedia, the free encyclopedia.Coprosma robusta, commonly known as karamu, is a flowering plant in the family Rubiaceae, which is endemic to New Zealand. It can survive in many climates, but is most commonly found in coastal areas, lowland forests, or shrublands. Karamu can grow to be around 6 meters (20 feet) tall, and grow leaves up to 12 centimeters (4.7 inches) long. Karamu is used for a variety of purposes in human culture. The fruit that karamu produces can be eaten, and the shoots of karamu are sometimes used for medical purposes.