Native Nepenthes of Singapore

Through evolution, some plants have developed the ability of obtaining some or most of their nutrients by consuming animals, typically insects and other arthropods. They are carnivorous plants. With the nutrients supplemented from animals, they have adapted to grow in places where the soil is thin or poor in nutrients, especially nitrogen, such as acidic bogs.

Basically, there are 5 ways carnivorous plants trap insects:

Adhesive traps function like flypaper. Leaves of the plant secrete sweet and sticky mucilage to draw preys.

Snap traps utilise rapid leaf movements. Venus flytraps lure prey inside their traps by producing sweet nectar. If the victim comes in contact with the trigger hairs inside the trap, the lobes close. When the victim try to escape, the movement provokes the plant's enzyme production. The enzymes digest the insect, and the leaf absorbs nutrients.

Lobster-pot traps force prey to move towards a digestive organ with inward-pointing hairs. The corkscrews insides are lined with directional hairs, making it so prey enters from slits along the leaf's body and glides down. The corkscrew leaves end in a chamber, which is basically the stomach of the corkscrew plant where digestion occurs.

Pitfall traps trap prey in a rolled leaf the contains a pool of digestive enzymes or bacteria. The pitcher plant sports exciting colors to attract its prey, as well as enticing smelling nectar that fills its bladder. The opening of the pitcher, as well as the interior walls, are very slippery, so once prey falls in it does not have a chance of escaping.

Bladder traps suck in prey with a bladder that generates an internal vacuum.

Pinguicula - Adhesive Trap

Sundew - Adhesive Trap

Venus Flytrap - Snap Trap

Sarracenia psittacina - Lobster-pot trap

Bottle Plant - Pitfall Trap

Nepenthes - Pitfall Trap

Nepenthes

Most of the carnivorous plants are not native plants of South-East Asia, except Nepenthes. Nepenthes uses its pitchers to trap insects. With the nutrients supplemented from their victims, they have adapted to grow in places where the soil is thin or poor in nutrients, especially nitrogen, such as acidic bogs.

Nepenthes are the tropical pitcher plants of the old world. Despite the fact that they are the only Genus of the Nepenthaceae family, there are more than 80 species found in regions such as the tropical West Africa, India, Northern Australia and Southeast Asia.

Nepenthes are certainly amongst the most spectacular evolutionary products of the plant kingdom. The astonishing beautifully shaped and colourful "pitchers" are actually modified leaves evolved after millions of years to trap insects and to utilise their nutritious remains as sustenance.

Trapping Mechanism

Pitcher plants attract insects with colour, and with nectar-secreting glands.

Once inside the pitcher, the insects are trapped. They cannot climb out, because the wall is slippery with wax. The rim of the pitcher has an overhanging row of teeth to further prevent the insects escape from the trap. Finally, the insects drown in the fluid in the pitcher, and their bodies digested by the fluid and absorbed by the plant.

Lid - acts like umbrella, prevents rainwater from diluting the fluid in the pitcher

Rim - has a row of overhanging teeth, prevents preys from climbing out of the pitcher

Inner wall - surface covered with wax, prevents preys from climbing up the wall

Enzyme secreting glands - Special glands secrete acids and enzymes that digest the dead insects. The pitcher wall absorbs the nutrients

Pitchers are modified leaves evolved after millions of years to trap insects

The pitcher plant sports exciting colors to attract its prey, as well as enticing smelling nectar that fills its bladder

Some pitchers can grow to 30 cm in size or even bigger and contain litres of viscous digesting fluid

Native Nepenthes of Singapore

There are many species of Nepenthes in peninsular Malaysia. However, at the southern tip of the peninsula, Singapore, there are only three species: N. ampullaria, N. gracilis and N. rafflesiana. They used to be quite common in the country side in the 1960's. With the city development converting Singapore into a city state in the past few decades, they are however confined to fewer habitats. With a watchful eye, they can be found in Bukit Timah, Mandai, Macritchie Reservoir and Kent Ridge Park.

Nepenthes Clusters in Kent Ridge Park
Nepenthes ampullaria	Nepenthes gracilis	Nepenthes Rafflesiana

Nepenthes ampullaria

Nepenthes ampullaria, the Flask-Shaped Pitcher-Plant, is a very distinctive and widespread species of Nepenthes, present in Borneo, Sumatra, Thailand, Peninsular Malaysia and Singapore.

Nepenthes ampullaria has largely moved away from carnivory and acquires a substantial portion of its nutrients from digesting leaf matter that falls to the forest floor. It is thus partially detritivorous.

Pitchers range in colouration from light green throughout to completely dark red. The pitchers of N. ampullaria from Singapore are almost exclusively green throughout or green with red speckles

Clusters of pitchers are also produced along the climbing stems

Upper pitchers are very rarely produced and are considerably smaller than those formed on rosettes or offshoots.

Nepenthes gracilis

[Macritchie Reservoir]

Female Flower

Male Flower

Nepenthes rafflesiana

Lower Pitcher

Nepenthes usually produce two morphological and sometimes even ecological different types of pitchers. Young plants in the rosette stadium have lower or ground pitchers. Their mouth is looking towards the tendril and they have 'wings' on the pitcher wall.

Upper Pitcher

When the plants begin to climb, they start to produce upper or aerial pitchers. These lack of wings and the tendril is on the backside of the pitcher. Often these two pitcher types look completely different and hard to recognise as parts of the same plant.

Most Nepenthes grow as lianas and some can climb more than ten meters up the trees. The tendril of their leaves helps them to get hold on trees and bushes they use as support. Some grow epiphytic, others usually stay as rosettes on the ground.

Male flower

Nepenthes are dioecious, that means there male and female plants. Inflorescences are long raceme- or panicle-like. The flowers have only four leaf (sepals) which are covered with nectar glands. The pollinators of some species seem to be flies and moth but beetles, bugs and ants are also observed to visit the flowers.

Female flower

The development of the fruit capsule takes about three months. It can contain 500 or more seed. Those are very light and have long wings to carried by the wind.

N. rafflesiana generally occurs in open, sandy, wet areas. It has been recorded from kerangas forest, secondary formations, margins of peat swamp forest, heath forest, and seaside cliffs.

The splendour of the flora is now captured by our skillfully craftsmen in their most natural forms.