The Argan (Argania spinosa, syn. A. sideroxylon Roem. & Schult.) is a species of tree endemic to the calcareous semi-desert Sous valley of southwestern Morocco. It is the sole species in the genus Argania.
Argan grows to 8-10 metres high, and live to 150-200 years old. They are thorny, with gnarled trunks. The leaves are small, 2-4 cm long, oval with a rounded apex. The flowers are small, with five pale yellow-green petals; flowering is in April. The fruit is 2-4 cm long and 1.5-3 cm broad, with a thick, bitter peel surrounding a sweet-smelling but unpleasantly flavoured layer of pulpy pericarp. This surrounds the very hard nut, which contains one (occasionally two or three) small, oil-rich seeds. The fruit takes over a year to mature, ripening in June to July of the following year.
The arganeraie forests now cover some 8,280 km² and are designated as a UNESCO Biosphere reserve. Their area has shrunk by about 50% over the last 100 years, owing to charcoal-making, grazing, and increasingly intensive cultivation. The best hope for the conservation of the trees may lie in the recent development of a thriving export market for argan oil as a high-value product.