Orange (Sweet Orange, Mandarin, or related Citrus species)
Kingdom: Plantae, Division: Tracheophyta, Class: Magnoliopsida, Order: Sapindales, Family: Rutaceae, Genus: Citrus, Species: C. sinensis · Rutaceae (Rue or Citrus family) · Simple (though evolutionarily reduced from a compound leaf), evergreen
Species
Citrus sinensis
Leaf Type
Simple (though evolutionarily reduced from a compound leaf), evergreen
Family
Rutaceae (Rue or Citrus family)
Shape
Elliptical to ovate with an acute to obtuse apex and rounded base
Size
Approximately 2 to 3 inches long, typical of many mature Citrus species leaves
Margin
Crenate to remotely serrulate or nearly entire
Arrangement
Alternate
Rarity
Very Common in cultivation and agricultural zones globally
Color & Pattern
Deep rich green on the upper surface, slightly paler on the underside, glabrous with no notable variegation
Venation Pattern
Pinnate and reticulate, with a prominent midrib and distinct lateral veins arching upward
Texture & Surface
Leathery (coriaceous), glabrous, and glossy on the upper surface with embedded translucent oil glands typical of the Rutaceae family
Description
This is a simple, evergreen leaf belonging to the Citrus genus, likely a sweet orange or related citrus fruit tree. The plant forms a small, dense, rounded evergreen tree or shrub with fragrant white flowers and highly valued hesperidium fruits. The leaves are leathery, aromatic when crushed due to oil glands, and persist on the tree for multiple years.
Key Features
Leathery texture, translucent oil dots visible against light, winged or narrowly margined petiole, distinct citrus aroma when crushed, and persistent evergreen nature
Habitat
Subtropical and tropical regions, thriving in full sun, well-draining slightly acidic to neutral soils, and moderate to high moisture with regular watering
Geographic Range
Native to tropical and subtropical Asia, widely cultivated globally in Mediterranean and subtropical climates worldwide
Condition Notes
The press-mounted leaf is in fair to good dried condition, showing slight curling along the margins and preservation flattening typical of a standard herbarium specimen
Interesting Facts
Citrus leaves contain specialized essential oil glands that release fragrant aromatic compounds when bruised. The sweet orange is a hybrid of ancient origin, likely between the pomelo and mandarin.
Medicinal & Uses
Citrus leaves and essential oils are widely used in traditional remedies, aromatherapy, perfumes, and flavoring. The fruits are rich in Vitamin C and consumed globally
Ecological Role
Serves as an important larval host plant for various swallowtail butterfly species (such as the Orchard Swallowtail), while flowers provide nectar for bees and other pollinators
Similar Species
Other Citrus species such as lemons (Citrus limon), limes (Citrus aurantiifolia), and grapefruits (Citrus paradisi), which can be distinguished by differences in petiole wing size, leaf shape, and aroma
Foraging Tips
Look in agricultural groves, backyard orchards, or conservatory greenhouses in warm climates. Crush the leaf gently to check for the distinct citrus fragrance
Toxicity Warning
Non-toxic for humans regarding the leaves, though certain essential oils concentrated from citrus can cause mild skin irritation or photosensitivity in sensitive individuals