Seeds from Citrus japonica Meiwa Kumquat. This sweet kumquat is a small round citrus fruits known for their edible skin and their tart flavor. Distinguished by their more round shape and their sweetness. Often referred to as the sweet kumquat entirely edible, rind, flesh by eating both the skin and flesh will its sweet-tart flavor balance be experienced. They do make excellent indoor container plants. Zones 8 to 11.