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Ocimum americanum

Family Name: Lamiaceae (Labiatae)
Common Name: Lime Basil, American Basil, Hoary Basil, 灰罗勒
Full Sun: 6-8h Moderate Water Fruit & Vegetable Herb & Spice Woody Herbaceous


Family Name
Genus Epithet
Species Epithet
Common Names

Classifications and Characteristics

Plant Division Angiosperms (Flowering Seed Plants) (Dicotyledon)
Plant Growth Form Shrub (Herbaceous)
Lifespan (in Singapore) Perennial
Mode of Nutrition Autotrophic
Maximum Height 0.5 m


Native Distribution Africa, China, Indian Subcontinent, Indo-China, Malesia
Native Habitat Terrestrial
Preferred Climate Zone Tropical, Sub-Tropical / Monsoonal

Description and Ethnobotany

Growth Form Small herbaceous plant with erect growth habit.
Foliage Gland-dotted on both surface.
Stems Stem and branched quadrangular, yellowish green, densely white-pilose in young plant.
Flowers Small, white to light blue flowers (1 cm long) are composed of an upper and lower lip, the lower lip being slightly larger. White stamens are slightly longer than the lower lip. Terminal inflorescence is composed of flowers in whorled arrangement. The flowers are similar to that of Ocimum basilicum, but the upper lip of the calyx is shorter (2 - 3 mm long compared to 4 - 6 mm long). The inside of the calyx is also densely hairy above the fruits.
Fruits Small, 1-seeded fruits are known as nutlets. In water the nutlet-wall produces a thick white cover of slimy threads within several minutes.
Habitat Often found in tropical climates, growing on roadsides, in fields, in teak forests, and in open waste place close to settlements.
Ethnobotanical Uses Edible Plant Parts (Edible Leaves)
Food (Fruit & Vegetable : Compared to sweet basil (O. basilicum) shrubby basil (O. gratissimum) and holy basil (O. tenuiflorum), which are very fragrant, O. americanum is mild in flavor. It is cultivated for the young leaves, which are eaten raw as a vegetable side-dish in Indonesia, Malaysia and Thailand.;Herb and Spice : The fragrant leaves are also added to various dishes with fishy or disagreeable smell. )
Medicinal ( In traditional medicine, hoary basil is used for several ailments. Decoctions are used for coughs, pounded leaves are used for respiratory problems, the whole plant is used in baths to treat rheumatism, renal colic and calcification.)
[Others]: The essential oil of the plant is used in soap and cosmetics.

Landscaping Features

Landscape Uses General, Parks & Gardens, Container Planting
Thematic Landscaping Economic Garden

Plant Care and Propagation

Light Preference Full Sun
Water Preference Moderate Water
Diseases No serious diseases and pets have been reported.
Propagation Method Seed


Foliage Retention Evergreen
Mature Foliage Colour(s) Green
Mature Foliage Texture(s) Smooth
Foliar Type Simple / Unifoliate
Foliar Arrangement Along Stem Opposite
Foliar Attachment to Stem Petiolate
Foliar Shape(s) Non-Palm Foliage (Lanceolate, Elliptical)
Foliar Margin Entire
Foliar Base Acute, Cuneate

Floral (Angiosperm)

Flower Colour(s) Blue, White
Flower Grouping Cluster / Inflorescence
Flower Location Terminal

Image Repository



Master ID 30737
Species ID 5057
Flora Disclaimer The information in this website has been compiled from reliable sources, such as reference works on medicinal plants. It is not a substitute for medical advice or treatment and NParks does not purport to provide any medical advice. Readers should always consult his/her physician before using or consuming a plant for medicinal purposes.
Species record last updated on: 19 August 2021.