Plant Diversity - Carnivorous Plants

When you hear the words 'carnivorous plants' the imagination tends to run wild. It's a bit frightening to think of plants eating animals when plants are usually the ones on the bottom of the food chain! Read on about carnivorous plants found in the Wet Tropics.

There are about 100 species of Sundews in the world and over half of them are found in Australia. In the Wet Tropics area, a species known as Drosera adelae grows on the shady forest floor in marshy areas. The 20 cm (8 inch) wide plant has long, narrow green leaves with a wine coloured edge and tiny tentacles. Flowers are tiny and brown and line the top of multiple flower stems (inflorescences) up to 30cm (12 inches) tall. The tips of the leaves exude a sticky fluid and when an insect lands on the tentacles, the leaf curls up trapping the insect. The sticky fluid contains digestive enzymes which reduce the body of an insect to a nourishing fluid which can be taken up by the plant. When all that remains of the insect is the exoskeleton, the leaves unfold and the empty shell falls away.

The Notched Sundew (Drosera schizandra) is endemic to the Wet Tropics area, occurring on only Mt Bartle Frere. It likes wet, sandy soil in deep shady areas. The pale green leaves are wedge shaped and broad, each being 10 cm (4 inches) by 5cm (2 inches).

Another group of carnivorous plants whose members are almost exclusively found in southeast Asia is the pitcher plant. The pitcher is usually a long, narrow receptacle filled with fluid which digests any insect (or even slightly larger animals which might fall in). Many of these plants include a 'lid' to the pitcher. The entire structure grows from a thick tendril which extends out of the tip of the leaves. One of the pitcher plants occurs in the coastal lowlands of the Wet Tropics area. This is the Climbing Pitcher Plant (Nepenthes mirabilis). The inside of its lid is usually a reddish colour in stark contrast to its 20cm (8 inch) long green pitchers. The more sunlight the plant receives, the more of a red tinge there is to the pitchers.

 
Thanks are extended to the Flecker Botanic Gardens slide library for the use of photos copyrighted by D.Warmington, P. Shanahan and G. Sankowski.