The citron is a fragrant citrus fruit, botanically classified as Citrus medica by both the Swingle and Tanaka systems. Citron was the first of the citrus fruits to appear in the Mediterranean Basin.
Citrus medica is a slow-growing shrub or small tree that reaches a height of about 8 to 15 ft (2 to 5 m). It has irregular straggling branches and stiff twigs and long spines at the leaf axils. The evergreen leaves are green and lemon-scented with slightly serrate edges, ovate-lanceolate or ovate elliptic 2.5 to 7.0 inches long. Petioles are usually wingless or with minor wings. The flowers are generally unisexual providing self-pollination, but some male individuals could be found due to pistil abortion.
Three compounds were isolated from Citrus medica L. var. sarcodactylis (Noot) Swingle. The structures were identified as limettin(I), stigmasta-5, 22-dien-3-ol(II) and palmilic acid(III) on the basis of UV, MS, IR, 1HNMR, 13CNMR and DEPT.