Carnivorous plants live in areas where the soil is very poor and lacking in nitrogen. The way they have adapted to overcome this problem is by trapping and digesting the bodies of insects. Tropical carnivorous plants are very similar to the ones from temperate climates, but are not always related. The ability to trap and digest insects has developed independently in several plant families, but they all achieve the same aim, which is to supplement the poor soil and take advantage of an ecological niche that other plants can not.
The tropical pitcher plants are members of the genus Nepenthes and are native to southeast Asia, primarily Borneo. They are low growing vines that climb up tree trunks or along the ground and produce pitchers from tendrils that grow on the leaf tips. Plants on the ground often produce ground pitchers that have a wing-type shape running vertically up the side, like a ladder for ground insects. Pitchers that hang in the air from plants growing higher up lack wings. The top of the pitchers are covered with a hood that secretes sweet nectar and also helps keep the rain from flooding the pitcher.
The traps work like other pitcher plants. The nectar lures in the insects with the promise of a meal, then the bugs lose their footing on the rim of the pitcher, fall in and die in the pool of liquid digestive enzymes at the bottom.
The Australian sundew (scientific name Drosera adelae) is native to the wet tropical areas of North Queensland in northeast Australia. These can get large for a sundew, with a width of over 1 foot and 8-inch long leaves. The leaves are covered with small hairs and a drop of very sticky fluid on the end of each hair. When an insect lands on the leaf, it gets hopelessly stuck, then dies and is eventually digested and absorbed by the plant.
Giant Mexican Butterwort
The giant Mexican butterwort is only a giant when compared to other butterworts. This species, Pinguicula gigantea, has a leaf span of 8 inches. The light green leaves grow in rosette shapes close to the ground. They are covered with a sticky mucus on both sides that act like fly-paper, trapping small insects that slowly get digested. It has a small yellow flower on a short stem that arises from the center of the plant.
It is native to San Bartholomé Ayautla, Oaxaca, Mexico, where it grows on the southern rock slopes of the Rio Uruapan canyon and its source rivers, sometimes in full sun.