Wiri Wiri Pepper. 100,000 - 350,000 Scoville Units. Capsicum Chinense. In the northeastern sector of South America rests the small country of Guyana. This is where the relatively rare Wiri Wiri pepper plant comes from. The Wiri Wiri pepper is a 1/2” round pepper that grows upright, and is quite hot. They turn from green, to orange, to red when mature. It is so cherry-like in appearance that sometimes it is called the Hot Cherry or Bird Cherry pepper.