Citron (scientific name: Citrus medica  L.), also known as枸櫞 or枸櫞子, is an irregularly branched shrub or small tree. New shoots, buds, and flower buds are dark purplish-red. Leaves are simple, rarely with unifoliate compound leaves; the leaf blades are elliptical or ovate-elliptical, with shallow blunt lobes at the margins. The raceme bears up to 12 flowers, with 5 petals. The fruit is elliptical, nearly round, or spindle-shaped with tapered ends, weighing up to 2000 grams. The peel is pale yellow, rough, and difficult to peel. The flesh is colorless, nearly transparent or pale creamy yellow, crisp, sour or slightly sweet, and fragrant. The seeds are small, smooth, with creamy white cotyledons, and are polyembryonic or monoembryonic. The flowering period is from April to May, and the fruiting period is from October to November.