Citrus trifoliata (Japanese Bitter Orange)

The Trifoliate Orange, Citrus trifoliata (syn. Poncirus trifoliata), is a member of the family Rutaceae. The species is unusual among citrus for having deciduous, compound leaves and pubescent (downy) fruit.

It is native to northern China and Korea, and is also known as the Japanese Bitter-orange (karatachi), Hardy Orange or Chinese Bitter Orange.

The plant is a fairly cold-hardy citrus and will tolerate moderate frost and snow, making a large shrub or small tree 4–8m tall. Because of its relative hardiness, citrus grafted onto Citrus trifoliata are usually hardier than when grown on their own roots.