The Araceae are a family of monocotyledonous flowering plants in which flowers are borne on a type of inflorescence called a spadix. The spadix is usually accompanied by, and sometimes partially enclosed in, a spathe (or leaf-like bract). Also known as the arum family, members are often colloquially known as aroids. This family of 114 genera and about 3,750 known species is most diverse in the New World tropics, although also distributed in the Old World tropics and northern temperate regions.
Description
Within the Araceae, species are often rhizomatous or tuberous; many are epiphytic, creeping lianas or vining plants, and the leaves and tissues of the entire plant nearly always contains irritating calcium oxalate crystals or raphides, in varying degrees. The foliage can vary considerably from species to species. The majority of species produce an inflorescence consisting of a spadix (which some compare to a corn cob, in appearance), which is nearly always surrounded by a modified leaf bract called a spathe. In monoecious aroids, possessing separate male and female flowers (but with both flowers present on one plant), the spadix is usually organized with female flowers towards the bottom and male flowers at the top. In aroids with perfect flowers, the stigma is no longer receptive when the pollen is released, thus preventing self-fertilization. Some species are dioecious.
Many plants in this family are thermogenic (heat-producing). Their flowers can reach up to 45 °C, even if the surrounding air temperature is much lower. One reason for this unusually high temperature is to attract insects (usually beetles) to pollinate the plant, rewarding the beetles with heat energy, in addition to preventing tissue damage in colder regions. Some examples of thermogenic aroids are Symplocarpus foetidus (eastern skunk-cabbage), Amorphophallus titanum (titan arum), Amorphophallus paeoniifolius (elephant-foot yam), Helicodiceros muscivorus (dead-horse arum lily), and...
