Smart green carnivores

Norway and other countries are home to plants that eat animals and the plants use smart traps to capture their dinners.

13. nov 2006 06:00

Sundew

Blærerot/ Nysgjerrigper 4-06PHOTO: SPL/ GV-PRESS Three species of sundew grow on bogs in Norway. The plant has sticky hairs on its leaves and insects get stuck on them. The hairs then bend in towards the captured insect. Sometimes a leave will roll up a bit around the prey. The leaf is covered with a mucous that contains a substance that dissolves the insect.

After the insect has been digested by the plant, the leaf straightens out and the hairs stand up once again. It is as though nothing had happened – and the plant stands ready to capture the next insect.

Flytraps

Kanneberar, insekt/ Nysgjerrigper 4-06 PHOTO: GV-PRESS The flytrap is related to the sundew. It is found in America and captures its food in a slightly different manner. The edge of the leaf is equipped with long spikes, and there are six small brushes inside the leaf proper. When an insect touches the brushes, the two halves of the plant clap shut like a trap.

The long spikes lock the leaftrap just like your fingers when you fold your hands. This leaves the insect trapped inside the plant. It is then dissolved by a liquid excreted by the plant and subsequently digested.

Butterwort

There are three species of butterwort in Norway. One of the species grows on grassy hillsides in the highlands. Butterwort also captures insects on its sticky, slimy leaves. It has fleshy leaves and is shaped like a rosette.

In old days, people in Norway made 'longmilk' from the butterwort. The leaves from the plants were placed on the bottom of a bucket. Then new milk and warm milk were added. After sitting for a few days, the milk was sour and viscous, so it would keep for a long time. Butterwort was also used to making herbal tea to relieve coughing and other respiratory diseases.

Bladderworts

[bilde3 "PHOTO: BJØRN RØRSLETT/NN/SAMFOTO" høyre] Five species of bladderworts grow in Norwegian waters. These plants lack roots and float freely in the water. They often have a few yellow flowers at the top. There are small bladders on the leaves or stems that can trap animals.

On the one side of the bladder wall there is a door with an opening and closing mechanism and some trigger hairs beside the trapdoor. When a tiny insect brushes against the hairs, the trapdoor opens abruptly and the prey and the water around it are sucked into the trap. The opening and closing of this trap is almost instantaneous – the whole process takes no more than 1/32 of a second!

Pitcher plants

[bilde4 "PHOTO: GV-PRESS" venstre] Pitcher plants mainly grow in tropical regions of Asia. Their leaves turn into tendrils that end in a growth that resembles a pitcher. The plant can have splendid colours that attract insects.

The inside of the pitcher is covered with digestive glands. These hold an insect after it falls into the pitcher. An enzyme as strong as gastric acid then dissolves the insect before the plant absorbs the nutrients.

Translation: Linda Sivesind

*Published in 'Nysgjerrigper' no. 4/06*