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Cratoxylum formosum (Jack) Dyer

Family Name: Hypericaceae
Common Name: Pink Mempat, Derum, Mempat, Entemu, Geronggang Biabas, Gerunggung, Kemutul, Kemutun, Mempitis, 越南黄牛木

Cratoxylum formosum (Pink Mempat) can grow up to 45 m tall in the wild but is much shorter in cultivation as an ornamental. This tree is native to Singapore and is preferred by the Archduke butterfly caterpillar as a food plant. You can easily spot this beauty when it is in full bloom, with a crown of light-pink flowers nestled among a flush of reddish foliage.

Full Sun: 6-8h Moderate Water Caterpillar Food Plant Native to Singapore Fruit & Vegetable Roadside Tree / Palm Ornamental Flowers Tree

Name

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

Classifications and Characteristics

Plant Division Angiosperms (Flowering Seed Plants) (Dicotyledon)
Plant Growth Form Tree (Big (>30m), Small (6m-15m))
Lifespan (in Singapore) Perennial
Plant Shape Rounded
Maximum Height 10 m to 45 m

Biogeography

Native Distribution South Andaman Islands, south China, Indochina, south Thailand, Sumatra, Malaysia, Singapore, Bangka Island, the Philippines, Borneo, Java, and Sulawesi
Native Habitat Terrestrial (Primary Rainforest, Secondary Rainforest, Monsoon Forest, Freshwater Swamp Forest, Riverine)
Preferred Climate Zone Tropical, Sub-Tropical / Monsoonal
Local Conservation Status Native to Singapore (Endangered (EN))

Description and Ethnobotany

Growth Form It is a medium to large-sized tree up to 45 m tall, but in Singapore, it is 10 m or shorter. Its bark is grey and scaly. The plant is easy to spot when its crown is covered with light pink flowers amidst the new foliage.
Foliage Its opposite, long-stalked leaves have fleshy to papery leaf blades that are usually narrowly to broadly oval, and 3.5–18 by 1–7.6 cm. Its new leaves have reddish-pink leaf blades that mature to green above and greenish below.
Flowers Its faintly fragrant flowers are 1.3–2.5 cm wide, with light pink petals. They are found in clusters of 1–6, in axils of fallen leaves or on bare twigs.
Fruits Its dark brown fruits are ellipsoid, 10–19 by 4–6 mm, and split open into three parts when ripe to release the winged seeds. Up to half of the bases of the fruits are covered by the sepals too. Its brownish seeds are narrowly drop-shaped, 6–7.5 by 2–4 mm, and many per fruit.
Habitat It grows in hill, primary or secondary forests, river edges, swamps, and on clay or sandy soils, up to 1,200 m altitude.
Associated Fauna It is the preferred local food plant for caterpillars of the archduke (Lexias pardalis dirteana). The adult of the archduke lays its eggs singly on the undersides of leaves of the host plant. Its flowers are also insect-pollinated.
Etymology Greek kratos, strength; Greek xulon, wood, referring to the strong timber; formosus, beautiful or handsome, referring to this species’ flowers.
Ethnobotanical Uses Edible Plant Parts (Edible Leaves)
Food (Fruit & Vegetable : The leaves are edible as they are believed to be beneficial for one’s health.)
Medicinal ( Colic and itch is treated by a decoction, and resin from the bark respectively. Skin problems can be treated by applying a pounded mixture of the bark, leaves and coconut oil.)
Timber & Products ( The wood is a commercial source of medium-weight hardwood known as derum. It is used for carving, charcoal, firewood, furniture, house construction, poles and turnery.  )

Landscaping Features

Landscaping The plant has attractive new foliage, and light pink, cherry blossom- like flowers. It is suitable for parks and roadsides. It can be propagated by seeds and stem cuttings. In Singapore, only a very low percentage of the seeds develop into seedlings. The saplings must be handled with caution during transplanting, as this species may have thorny stems. Its tolerance for a wide range of soil moisture conditions makes it suitable for damp to sandy sites.
Desirable Plant Features Ornamental Flowers
Plant & Rootzone Preference - Tolerance Moist Soils, Well-Drained Soils, Fertile Loamy Soils, Heavy Clay Soils
Landscape Uses Roadside Tree / Palm, Parks & Gardens, Small Gardens, Riverine, Shade Providing Tree / Palm

Fauna, Pollination and Dispersal

Fauna Pollination Dispersal Associated Fauna Caterpillar Food Plant (Leaves, Associated with: Lexias pardalis)
Pollination Method(s) Biotic (Fauna) (Insects (Butterfly, Moth), Insects (Bee))
Seed or Spore Dispersal Abiotic

Plant Care and Propagation

Light Preference Full Sun
Water Preference Moderate Water
Plant Growth Rate Moderate
Propagation Method Seed, Stem Cutting

Foliar

Foliage Retention Deciduous
Mature Foliage Colour(s) Green
Mature Foliage Texture(s) Papery, Thick
Prominent Young Flush Colour(s) Pink, Red
Foliar Type Simple / Unifoliate
Foliar Arrangement Along Stem Opposite
Foliar Attachment to Stem Petiolate
Foliar Shape(s) Non-Palm Foliage (Oval)
Foliar Venation Pinnate / Net
Foliar Margin Entire
Leaf Area Index (LAI) for Green Plot Ratio 3.0 (Tree - Intermediate Canopy)

Floral (Angiosperm)

Flower & Plant Sexuality 1 Bisexual Flowers
Flower Colour(s) Pink
Flower Grouping Cluster / Inflorescence
Flower Location Axillary
Flower Symmetry Radial
Individual Flower Shape Stellate / Star-shaped

Fruit, Seed & Spore

Mature Fruit Colour(s) - Angiosperms and Gymnosperms Brown
Fruit Classification Simple Fruit
Fruit Type 1 Dehiscent Dry Fruit

Image Repository

Images

Others

Master ID 1537
Species ID 2830
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: 17 September 2020.
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