Rough lemon (Citrus × jambhiri Lush.) is the fruit and the tree of a citrus hybrid. Like the rangpur, it is a cross between mandarin orange and citron.
Rough lemon is a cold-hardy citrus and can grow into a large tree.
The rough lemon is mostly rind, making it less edible than other citrus. As a result, the rough lemon is mainly used for citrus rootstock,[1] however areas of South Africa and India do consume it. There are several cultivars of rough lemon that can serve as a citrus rootstock, including 'Florida',[2] 'Schaub',[3] and 'Vangassay' rough lemon.[4] The process for using the rough lemon as a citrus rootstock would start with mashing up the rough lemons. The mashed up rough lemons would then be put in a furrow, which is a long trench. This yellow mash would produce seedlings, which would end up growing into orange or grapefruit trees through shield budding, also known as T budding.