Typha

Typha /ˈtaɪfə/ is a genus of about 30 species of monocotyledonous flowering plants in the family Typhaceae. These plants have a variety of common names, in British English as bulrush or reedmace, in American English as reed, cattail, swamp sausage, or punks, in Australia as cumbungi or bulrush, in Canada as bulrush or cattail, and in New Zealand as raupō. Other taxa of plants may be known as bulrush, including some sedges in Scirpus and related genera. Typha /ˈtaɪfə/ is a genus of about 30 species of monocotyledonous flowering plants in the family Typhaceae. These plants have a variety of common names, in British English as bulrush or reedmace, in American English as reed, cattail, swamp sausage, or punks, in Australia as cumbungi or bulrush, in Canada as bulrush or cattail, and in New Zealand as raupō. Other taxa of plants may be known as bulrush, including some sedges in Scirpus and related genera. The genus is largely distributed in the Northern Hemisphere, where it is found in a variety of wetland habitats. The rhizomes are edible. Evidence of preserved starch grains on grinding stones suggests they were already eaten in Europe 30,000 years ago. Typha are aquatic or semi-aquatic, rhizomatous, herbaceous perennial plants.:925 The leaves are glabrous (hairless), linear, alternate and mostly basal on a simple, jointless stem that bears the flowering spikes. The plants are monoecious, with unisexual flowers that develop in dense racemes. The numerous male flowers form a narrow spike at the top of the vertical stem. Each male (staminate) flower is reduced to a pair of stamens and hairs, and withers once the pollen is shed. Large numbers of tiny female flowers form a dense, sausage-shaped spike on the stem below the male spike. In larger species this can be up to 30 centimetres (12 in) long and 1 to 4 centimetres (0.4 to 2 in) thick. The seeds are minute, 0.2 millimetres (0.008 in) long, and attached to fine hairs. When ripe, the heads disintegrate into a cottony fluff from which the seeds disperse by wind. Typha are often among the first wetland plants to colonize areas of newly exposed wet mud, with their abundant wind-dispersed seeds. Buried seeds can survive in the soil for long periods of time. They germinate best with sunlight and fluctuating temperatures, which is typical of many wetland plants that regenerate on mud flats. The plants also spread by rhizomes, forming large, interconnected stands. Typha are considered to be dominant competitors in wetlands in many areas, and they often exclude other plants with their dense canopy. In the bays of the Great Lakes, for example, they are among the most abundant wetland plants. Different species of cattails are adapted to different water depths. Well-developed aerenchyma make the plants tolerant of submersion. Even the dead stalks are capable of transmitting oxygen to the rooting zone. Although Typha are native wetland plants, they can be aggressive in their competition with other native species. They have been problematic in many regions in North America, from the Great Lakes to the Everglades. Native sedges are displaced and wet meadows shrink, likely as a response to altered hydrology of the wetlands and increased nutrient levels. An introduced or hybrid species may be contributing to the problem. Control is difficult. The most successful strategy appears to be mowing or burning to remove the aerenchymous stalks, followed by prolonged flooding. It may be more important to prevent invasion by preserving water level fluctuations, including periods of drought, and to maintain infertile conditions. Typha are frequently eaten by wetland mammals such as muskrats, which also use them to construct feeding platforms and dens, thereby also providing nesting and resting places for waterfowl.