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Pterocarpus indicus Willd.

Family Name: Fabaceae (Leguminosae)
Synonyms: Lingoum indicum (Willd.) Kuntze; Lingoum wallichii (Wight & Arn.) Pierre; Pterocarpus wallichii Wight & Arn; Pterocarpus zollingeri Miq
Common Name: Angsana, Sena, Burmese Rosewood, Philippine Mahogany, Andaman Redwood, Red Sandalwood, Padouk, Padauk, Narra, Pokok Sena, 紫檀木, 青龙木, 印度紫檀

Pterocarpus indicus, locally known as Angsana, is an iconic tree commonly cultivated along the roads of Singapore. The spreading dome-shaped crown and drooping branches provide shade to pedestrians. When in bloom, the tree puts on an impressive yet short-lived display where the whole crown is covered with vibrant yellow flowers. The fruit pods are disc-like and dispersed by the wind.

Full Sun: 6-8h Moderate Water Coastal Roadside Tree / Palm Fragrant Ornamental Flowers Tree

Name

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

Classifications and Characteristics

Plant Division Angiosperms (Flowering Seed Plants) (Dicotyledon)
Plant Growth Form Tree (Big (>30m))
Lifespan (in Singapore) Perennial
Mode of Nutrition Autotrophic
Plant Shape Rounded, Weeping / Pendulous
Maximum Height 40 m
Tree or Palm – Trunk Diameter 2 m

Biogeography

Native Distribution India, China, Laos, Cambodia, Vietnam, Thailand and Malesia.
Native Habitat Terrestrial
Preferred Climate Zone Tropical, Sub-Tropical / Monsoonal
Local Conservation Status Exotic

Description and Ethnobotany

Growth Form It is an evergreen to semi-deciduous tree, up to 40 m tall with plank-like buttresses. It has spreading dome-shaped crown and drooping branches. The bark is grey-brown, finely fissured and scaly. It may produce red sap when cut. The trunk is often multi-stemmed near the base.
Foliage Leaves are alternate, odd-pinnate (imparipinnate) and 20 – 25 cm long. The leaf stalk (petiole) is 1.5 – 4 cm long. Each leaf has 5 – 11 leaflets which are broadly ovate to elliptic shaped (4 – 15 cm long and 2 – 9 cm wide). The terminal leaflet is larger than the other leaflets. Each leaflet has 8 – 10 pairs of lateral veins and the midrib is flat or impressed above. The tip of the leaflet is abruptly acuminate to mucronate while the base is rounded to broadly cuneate. Stipule is lanceolate (1 – 1.5 cm long) and falls off early. Young leaves are sparsely hairy, becoming smooth and hairless (glabrous) as they mature.
Flowers Occurring on the upper leaf axils and terminal ends of the branches, the inflorescence is a branched cluster (panicle) or a raceme, about 10 – 20 cm long. The flower is bright yellow, fragrant and about 1.5 cm long. Each flower comprises of five petals, namely one broadly ovate to orbicular standard petal, two oblong wing petals and two oblong keel petals. Within the keel, there are 10 stamens which occur in 2 bundles of 5 (diadelphous).
Fruits Fruit pod is disc-like (3 – 5 cm diameter), with a central seed-bearing portion and a flattened wing surrounding the central part. Each pod contains about 1 – 2 seeds within. Young fruit pods are green with golden hairs and gradually becoming pale brown and smooth as they ripen. The fruit pods do not split open even when ripe (indehiscent). The seed is brown, and oblong to kidney-shaped (0.8 – 1 cm long and 0.4 – 0.5 cm wide).
Habitat It is found along margins and open areas of evergreen forest, up to 600 m altitude.
Similar It closely resembles Pterocarpus macrocarpus . The leaflets and fruit characters help to tell the two species apart. The mature leaflets of Pterocarpus indicus are broadly ovate to elliptic shaped and glabrous on both surfaces. In addition, the midrib is flat or impressed above. On the other hand, Pterocarpus macrocarpus has ovate to oblong leaflets and sparse hairs on the lower surface of the leaflets. The midrib is raised above. The fruit pod of Pterocarpus indicus is smaller (3-5 cm diameter) while Pterocarpus macrocarpus fruit pod is bigger (5-10 cm in diameter)
Associated Fauna Flowers are pollinated by insects.
Cultivation It thrives in moist sandy loam or clay loam soil, and can tolerate compacted clayey soils found in urban sites. It can be propagated by seeds and stem cutting. Seeds germinate better when they are extracted from the indehiscent fruit pods before sowing. Widely used as 'instant tree' in Singapore during 1960s, it is a popular shade tree thanks to its rapid growth and ability to root from large branch-cuttings. Many Angsana trees in Singapore are unfortunately severely affected by fungal epidemic (Fusarium Wilt) during 1980s. It is also prone to being attacked by leaf-mining caterpillars of a moth (Neolithocolletis pentadesma). During severe infestation, the leaves may become unsightly and even completely defoliated. The use of systemic soil drench or trunk-injection pesticides may help to control the caterpillar infestation.
Etymology The genus ‘Pterocarpus’, in Greek, means winged seed. The species epithet 'indicus' refers to India, one of the places where it occurs naturally.
Ethnobotanical Uses Medicinal ( In Laos and Vietnam, leaves and bark are used as a folk remedy to treat vomiting and nausea. The red exudates, also known as Dragon’s Blood, is used in traditional folk medicine to treat diarrhoea and dysentery. )
Timber & Products ( The wood is hard, durable, easy to work with and does not blunt tools rapidly because it contains very little or no silica. The timber is reddish brown with darker irregular streaks and is highly prized for its decorative wood pattern. The wood is used for panelling, cabinetry, cart wheels, carving, construction, furniture, canoe, and musical instruments. Fresh and dry sawdust may produce an aromatic scent, and may cause nose or throat irritation.)
Cultural / Religious ( It is recognised as the national tree of the Philippines in 1934. Heritage Tree: There are 10 individuals of Pterocarpus indicus listed as Heritage Trees in Singapore. They are found all over various parts of Singapore. To find out more about these trees, please visit the Heritage Tree Register.)
[Others]: The mature leaves are used as shampoo in Laos and Vietnam. In Indonesia, the flowers and very young leaves are reportedly edible.

Landscaping Features

Landscaping When in bloom, the tree puts on an impressive display where the whole crown is covered with vibrant yellow flowers. These flowers often only last for a day and fall off the next morning, creating yellow carpets on the ground.
Desirable Plant Features Ornamental Flowers, Fragrant (Flowers) (Day)
Plant & Rootzone Preference - Tolerance Fertile Loamy Soils, Well-Drained Soils, Easy to Grow, Saline Soils / Salt Spray
Landscape Uses Roadside Tree / Palm, Coastal, Shade Providing Tree / Palm
SGMP Treatment
Usage Hazard - Cons Remarks Branches are weak and prone to be broken during storms.
Plant & Rootzone Preference or Tolerance Remarks It thrives in moist sandy loam or clay loam soil, and can tolerate compacted clayey soils found in urban sites.

Fauna, Pollination and Dispersal

Fauna Pollination Dispersal Associated Fauna Caterpillar Moth Food Plant
Pollination Method(s) Biotic (Fauna) (Insects (Bee))
Seed or Spore Dispersal Abiotic (Wind)

Plant Care and Propagation

Light Preference Full Sun
Water Preference Moderate Water
Plant Growth Rate Fast to Moderate
Maintenance Requirements Moderate
Operational Notes
Diseases Many Angsana trees in Singapore are unfortunately severely affected by fungal epidemic (Fusarium Wilt) during 1980s. It is also prone to being attacked by leaf-mining caterpillars of a moth (Neolithocolletis pentadesma). During severe infestation, the leaves may become unsightly and even completely defoliated. The use of systemic soil drench or trunk-injection pesticides may help to control the caterpillar infestation.
Propagation Method Seed, Stem Cutting
Propagule Establishment Remarks Cuttings of branches root easily.

Foliar

Foliage Retention Evergreen, Drought / Semi-Deciduous
Mature Foliage Colour(s) Green
Mature Foliage Texture(s) Smooth
Foliar Type Compound (Odd-Pinnate)
Foliar Arrangement Along Stem Alternate
Foliar Attachment to Stem Petiolate
Foliar Shape(s) Non-Palm Foliage (Ovate, Elliptical)
Foliar Venation Pinnate / Net
Foliar Margin Entire - Wavy / Undulate
Foliar Apex - Tip Acuminate, Mucronate
Foliar Base Rounded / Obtuse, Cuneate
Typical Foliar Area Notophyll ( 20.25cm2 - 45 cm2 )
Leaf Area Index (LAI) for Green Plot Ratio 4.0 (Tree - Dense Canopy)

Non - Foliar and Storage

Trunk Type (Non Palm) Woody
Mature Bark Texture Fissured, Scaly
Stem Type & Modification Woody
Root Type Underground

Floral (Angiosperm)

Flower & Plant Sexuality 1 Bisexual Flowers
Flower Colour(s) Yellow / Golden
Flower Texture(s) Thin
Flower Grouping Cluster / Inflorescence
Flower Location Axillary, Terminal
Flower Symmetry Bilateral
Individual Flower Shape Papilionaceous / Pea-shaped
Inflorescence Type Raceme, Panicle
Flowering Period A Few Times Yearly
Flowering Opening Time Daytime
Flower Lifespan on Plant 1 Day
Flowering Habit Polycarpic
Flowering Period Remarks Ocassional mass-blooming triggered by unknown factors, possibly dry weather and cool nights.

Fruit, Seed and Spore

Mature Fruit Colour(s) - Angiosperms and Gymnosperms Brown
Mature Fruit Texture(s) Papery
Fruit Classification Simple Fruit
Fruit Type 1 Indehiscent Dry Fruit
Mature Seed Colour(s) Brown
Seed Quantity Per Fruit Few (1-5)

References

References

Balslev, H. and Chantaranothai, P. (2018). Leguminosae-Papilionoideae. In: Santisuk, T., Chayamarit, K. and Balslev, H. (eds) Flora of Thailand, vol 4 part 3.1. Pp. 221-371. Bangkok: The Forest Herbarium, Department of National Parks, Wildlife and Plant Conservation

Gardner, S., Sidisunthorn, P., & Chayamarit, K. (2016). Forest Trees of Southern Thailand. Volume 2 (Eu – Me). The Forest Herbarium, Bangkok, The Royal Botanic Gardens, Kew. Pp. 749−1530. Bangkok: Kobfai Publishing Project

Hoang Van Sam, Nanthavong, K. & Kessler, P.J.A. (2004). Trees of Laos and Vietnam: a field guide to 100 economically or ecologically important species. Blumea 49: 201–349

Lemmens, R.H.M.J. and Soerianegara, I. (eds). (1993). Plant Resources of South-East Asia Volume 5 (1). Timber trees: Major commercial timbers. Indonesia: Prosea Foundation. 610 pages.

Whitmore, T.C. (1972). Leguminosae. In: Whitmore, T.C. (ed) Tree Flora of Malaya: A Manual for Foresters, vol. 1. Kuala Lumpur: Longman Sdn. Bhd.

 

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Master ID 1800
Species ID 3093
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: 05 January 2022.
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