Atypical Adaptations
Carnivorous plants are ones that have to find their required nutrients through processes other than uptaking from the soil. While most plants absorb nitrogen from the soil through their roots, carnivorous plants absorb it from their prey through their leaves.They tend to live in nutrient poor habitats and have developed adaptations, although seemingly strange, to access nutrients in novel ways. These plants will obtain some nutrients by digesting invertebrates, sometimes even small mammals or amphibians. Often this group will be referred to as “insectivorous” plants due to invertebrates making up the majority of their diet. Not surprisingly, they mostly inhabit wetlands; bogs and fens are typically nutrient poor and acidic but in full sun throughout the year.
In addition to their extraordinary survival tactics, carnivorous plants are also very attractive and interestingly formed, making them high value additions for water gardens and features. Many of these plants, and others as discussed in previous posts, are rare, threatened or endangered due to habitat destruction or loss and over collection. If you are interested in making carnivorous plants a part of your landscape don’t wild-collect them, many can be purchased from growers working on conservation of the species by domestically propagating vegetatively or through tissue cultures.
Discussed below are examples of carnivorous plants and their specific adaptations, this is not a complete list as over 13 species have been known to inhabit one bog! If you would like more information please visit the International Carnivorous Plant Society web page at: http://www.carnivorousplants.org/
There are 10 species native to the US belonging to the genus Sarracenia, pitcher plants. These plants use “pitfall traps” to entrap prey, in which leaves are deeply infolded leading to slippery pools filled with digestive enzymes.
There are 152 known species in the genus Drosera, that of the sundew. They are commonly found throughout temperate and tropical climates around the world. Sundews employ a “flypaper” trap adaptation, where leaves are covered with stalked glands which secrete sticky mucilage.
There is only one known species within the Aldrovanda, waterwheel, genus. It is found in aquatic habitats in Australia, Asia and Europe but used to be spread throughout Japan, Africa and India. This plant uses the same predation mechanism as the more commonly known Venus flytrap; the “snaptrap” where hinged leaves snap shut when trigger hairs are stimulated.
Bladderwort is among the most diverse and widespread genus, Utricularia, with 220 known species inhabiting temperate and tropical wetlands around the world. Bladderwort uses the “suction trap” to secure its meals; highly modified bladder shaped leaves have a hinged door lined with trigger hairs.
The corkscrew plant is a member of the Genlisea genus along with some 20 others. They occupy habitats found in Africa, Madagascar and South America. The corkscrew plants employ the “lobster pot” method, where their traps are twisted, tubular channels lined with glands and hairs.
