The Canadian Encyclopedia — neutral, cited, updated
July 26, 2026Sources cited
Canadianwire.
Canada’s encyclopedia & explainer
Home›Science & Nature›Fruit›Citrus
Science & Nature • Fruit

Citrus

Citrus is a genus of flowering trees and shrubs in the rue family (Rutaceae) that produces fleshy fruits such as oranges, lemons, limes, grapefruits, and mandarins.

By Ethan Anderson| Reviewed by Olivia Bennett, Standards & Fact-Checking Lead| Updated July 26, 2026|2 min read| Fact-checked

Citrus is a genus of flowering trees and shrubs in the rue family (Rutaceae) that produces fleshy fruits such as oranges, lemons, limes, grapefruits, and mandarins. The fruits are typically segmented, juicy, and covered by a thick aromatic rind. Citrus plants are widely cultivated in warm regions and are important food crops worldwide.

Botany

Citrus plants are evergreen trees or shrubs with glossy oval leaves, often thorny stems, and highly fragrant white flowers. Their fruits have a segmented interior filled with juice vesicles and a leathery rind with oil glands.

Fruits and hybrids

Many familiar citrus fruits are the result of extensive hybridization, especially oranges, lemons, grapefruits, and limes. Botanically important species include citron, mandarin, and pomelo, which have played major roles in citrus breeding and classification.

Origin and cultivation

Citrus is native to tropical and subtropical parts of Asia and nearby regions, including Southeast Asia and Australia. Today it is grown in many warm countries and is one of the most widely cultivated fruit groups in the world.

Uses

Citrus fruits are eaten fresh, juiced, and processed into a wide range of food products. They are also valued for their aroma, peel oils, and culinary uses.

Key facts

  • Citrus is a genus in the rue family, Rutaceae.
  • Its fruits are a type of berry called a hesperidium.
  • The genus includes major crops such as oranges, lemons, limes, grapefruits, citrons, pomelos, and mandarins.
  • Citrus plants are usually evergreen trees or shrubs with glossy leaves and many species have thorns.
  • Citrus originated in parts of Asia and the nearby Australasian region and is now cultivated widely in warm climates.
🍁
Canadian context

Citrus is widely available in Canada through imports, and citrus fruits are a common part of Canadian diets, food retail, and juice products.

Frequently asked questions

What is citrus?
Citrus is a genus of flowering trees and shrubs in the family Rutaceae that produces fruits such as oranges, lemons, limes, and grapefruits.
Are citrus fruits berries?
Botanically, citrus fruits are a specialized type of berry called a hesperidium.
Where did citrus originate?
Citrus originated in tropical and subtropical parts of Asia and nearby regions such as Southeast Asia and Australia.
Why do citrus fruits smell strongly?
Their peels contain oil glands that produce aromatic compounds, which give citrus fruits their distinctive scent.
Which fruits are included in citrus?
Common citrus fruits include oranges, lemons, limes, grapefruits, mandarins, citrons, and pomelos.

References

  1. Encyclopaedia Britannica — https://www.britannica.com/plant/Citrus
    Supports: Genus classification, fruit structure, plant characteristics, and common citrus species.
  2. Wikipedia — https://en.wikipedia.org/wiki/Citrus
    Supports: Native range and general overview of the genus.
  3. Encyclopedia.com — https://www.encyclopedia.com/food/encyclopedias-almanacs-transcripts-and-maps/citrus-fruit
    Supports: Origin in Asia, cultivation, common fruits, and uses.