Citrus ×taitensis, commonly known as Rough Lemon, is an evergreen tree resulting from the artificial hybridization of C. medica (citron) and C. reticulata (mandarin orange). It is characterized by its thick, bumpy rind and is primarily used as a rootstock for other citrus cultivars due to its hardiness and disease resistance. Rough Lemon typically grows to a height and width of 12-20 feet (4-6 meters), with a rounded canopy and dense foliage. The leaves are glossy green, and the tree produces fragrant white flowers followed by large, yellow, rough-skinned lemons throughout the year, with the main fruiting season in late winter to early spring.

The Rough Lemon tree is valued for its vigorous growth and adaptability to various soil types, making it an excellent rootstock choice. It is also grown for ornamental purposes in gardens and landscapes where space allows. This species requires full sun exposure to thrive and prefers well-drained soils with regular watering, although it can tolerate some drought once established. While it is not commonly grown for fruit production due to the poor quality of its lemons, it is an important component in the cultivation of more desirable citrus varieties. Gardeners should be aware that Rough Lemon can be susceptible to common citrus pests and diseases, such as citrus canker and root rot. It is also important to note that the tree has thorns, which can be a hazard in garden settings.CC BY-SA 4.0