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Costus woodsonii


Costus woodsonii Maas

Family Name: Costaceae
Common Name: Scarlet Spiral Flag, Red Button Ginger


Family Name
Genus Epithet
Species Epithet
Name Authority
Name Status (botanical)
Common Names

Classifications and Characteristics

Plant Division Angiosperms (Flowering Seed Plants) (Monocotyledon)
Plant Growth Form Herbaceous Plant
Lifespan (in Singapore) Perennial
Mode of Nutrition Autotrophic
Maximum Height 1 m to 2 m
Maximum Plant Spread / Crown Width 0.6 m to 1 m


Native Distribution Nicaragna to Colombia
Native Habitat Terrestrial (Primary Rainforest, Secondary Rainforest)
Preferred Climate Zone Tropical

Description and Ethnobotany

Growth Form It is a perennial herbaceous plant about 1-2 m tall, with a clump forming growth habit.
Foliage The broadly elliptical leaves (15 cm long, 8 cm wide) are hairless, glossy and spirally arranged along the stems.
Stems Round, succulent stems are produced by an underground horizontal stem known as a rhizome. The aboveground stems are erect to leaning and loosely spiraled.
Flowers The inflorescence is cylindrical with a tapered tip (6-10 cm long) and occurs at the stem tip. The bracts are tightly overlapped, bright red and waxy. The reddish-orange, tubular flowers have a yellow-orange lip near the apex. They emerge at the top of the inflorescence, 1-3 at a time from between the bracts.
Fruit The dry, dehiscent fruit is known as a capsule. It is woody and approximately round to egg-shaped. 
Associated Fauna Ants are attracted to the extrafloral nectaries which occur between the bracts and supply nectar. The ants do not pollinate the tubular flowers, but they may help to protect the developing fruits from damage by fly larvae.
Cultivation It grows best in rich, moist soil in semi-shade, being susceptible to sunburn under hot afternoon sun. Feed once a month with a balanced fertilizer such as one with a NPK ratio of 15-15-15.
Etymology The specific epithet 'woodsonii' honours Dr. Robert Woodson Jr. (1904-1963), curator of the Missouri Botanical Garden Herbarium.
Ethnobotanical Uses Edible Plant Parts : Edible Flowers

Landscaping Features

Desirable Plant Features Ornamental Flowers
Landscape Uses General, Parks & Gardens, Small Gardens, Coastal, Flowerbed / Border, Container Planting

Plant Care and Propagation

Light Preference Semi-Shade
Water Preference Occasional Misting, Lots of Water
Rootzone Tolerance Moist Soils, Well-Drained Soils, Saline Soils / Salt Spray, Fertile Loamy Soils
Diseases It is generally resistant to disease.
Propagation Method Stem Cutting (Tip, Herbaceous), Division, Aerial Plantlet
Propagation Method Remarks The stem can be cut into several pieces for propagation. Plantlets form at the base of withered inflorescences.


Mature Foliage Colour(s) Green
Mature Foliage Texture(s) Smooth, Glossy / Shiny
Prominent Young Flush Colour(s) Green
Young Flush Texture(s) Smooth
Foliar Type Simple / Unifoliate
Foliar Arrangement Along Stem Spiral
Foliar Attachment to Stem Sessile
Foliar Shape(s) Non-Palm Foliage (Elliptical)
Foliar Venation Parallel
Foliar Margin Entire
Foliar Apex - Tip Acute
Leaf Area Index (LAI) for Green Plot Ratio 3.5 (Shrub & Groundcover - Monocot)

Floral (Angiosperm)

Flower Colour(s) Red, Orange, Yellow / Golden
Flower Grouping Cluster / Inflorescence
Flower Location Terminal

Fruit, Seed and Spore

Mature Fruit Colour(s) White, Red
Mature Fruit Texture(s) Smooth
Mature Seed Colour(s) Black

Image Repository



Master ID 580
Species ID 1875
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: 14 October 2021.