The curry tree (Murraya koenigii) is a tropical to sub-tropical tree in the family Rutaceae, which is native to India.
Its leaves are used in many dishes in India and neighbouring countries. Often used in curries, the leaves generally go by the name "curry leaves", though they are also translated as "sweet neem leaves" in most Indian languages (as opposed to ordinary neem leaves which are bitter).
It is a small tree, growing 4–6 m (13-20 feet) tall, with a trunk up to 40 cm diameter. The leaves are pinnate, with 11-21 leaflets, each leaflet 2–4 cm long and 1–2 cm broad. They are highly aromatic. The flowers are small, white, and fragrant. The small black shiny berries are edible, but their seeds are poisonous.
The species name commemorates the botanist Johann König.
The leaves are highly valued as seasoning in southern and west-coast Indian cooking, and Sri Lankan cooking, especially in curries, usually fried along with the chopped onion in the first stage of the preparation. They are also used to make thoran, vada, rasam and kadhi. In their fresh form, they have a short shelf life, and they don't keep well in the refrigerator. They are also available dried, though the aroma is largely inferior.
The leaves of Murraya koenigii are also used as a herb in Ayurvedic medicine. They are much valued as an anti-diabetic, antioxidant, antimicrobial, anti-inflammatory, hepatoprotective, anti-hypercholesterolemic, etc. They also contain iron.
Although most commonly used in curries, leaves from the curry tree can be used in many other dishes to add flavor. In Cambodia, Khmer toast the leaves in open flame or roasted it to a crunch and crushed it into a soured soup dish called Maju Krueng.
In the absence of tulsi leaves, curry leaves are used for rituals and pujas.
Seeds must be ripe and fresh to plant; dried or shriveled fruits are not viable. One can plant the whole fruit, but it's best to remove the pulp before planting in potting mix that is kept moist but not wet.
Stem cuttings can be also used for propagation.
A 2011 study of girinimbine, a carbazole alkaloid isolated from this plant, found that it inhibited the growth and induced apoptosis in human hepatocellular carcinoma, HepG2 cells in vitro.