Citrus limon (L.) Osbeck

A small evergreen tree with short spines. It grows to 7 m high and spreads to 3 m across. It branches freely. Young branches are often reddish. Leaves are about 5-12 cm long. They are green and drawn out to a point, with notched edges. The leaf stalk is usually not winged. The leaves do not have much of a scent. The flowers are white, with 5 petals and have a strong sweet smell. They are 4-5 cm across. The fruit is oval shaped and with a knob at the end. Fruit can be 7-15 cm long. The skin is fairly thin, rough and light yellow. The flesh is sour and the seeds are oval.

A subtropical plant. Trees do not do well on the coast in the tropics but they grow well at about 1300 m and will grow up to 2200 m altitude in Papua New Guinea. They prefer a light to medium, well drained soil. They are drought resistant but most varieties are frost tender. They need a temperature above 3-5°C for growth. They suit warm temperate regions. In Brisbane Botanical Gardens. It suits hardiness zones 9-11.

The fruit is mostly too sour to eat fresh but the juice is used to make drinks. The juice is used in tea, ice cream, sauces, salads, salad dressings and marinades. It can be a coagulant in cheese making. The peel is used as seasoning in chocolate. The peel is candied in syrup. The inner parts of the peel and pulp are used for low-methoxyl pectins used for sugarless fruit jams and jellies. The dried leaves are added to teas for flavouring. The flowers are eaten in ice cream, fritters and jams. Caution: Large doses can erode teeth enamel and cause dermatitis.

Many trees are seedlings. Better trees are grafted.