Ichang Lemon is an Ichang papeda crossed with a pummelo (Citrus ichangensis x Citrus maxima). It originated in China, where it is called Shanguan, which means "fragrant ball". This very vigorous and spreading tree is quite ornamental, resembling a grapefruit tree with large wide leaves with a flared petiole. It produces clusters of large bumpy seedy yellow grapefruit like fruits, which can be used like lemons. The fruit is extremely juicy with each one producing as much as a half cup of juice. When over ripe, it tastes like grapefruit and is quite edible with a little sugar. The Ichang lemon is very hardy, enduring temperatures down to 10F and below with no permanent damage as long as it is protected from the wind. Uses: Eating, Cooking, Juice.- Silica
Taken from "Hardy Citrus For The Southeast".