Cattails

Typha leaves are alternate and mostly basal to a simple, jointless stem that eventually bears the flowering spikes. The rhizomes spread horizontally beneath the surface of muddy ground to start new upright growth, and the spread of Typha is an important part of the process of open water bodies being converted to vegetated marshland and eventually dry land.

Typha plants are monoecious and bear unisexual, wind-pollinated flowers, developing in dense spikes. 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. The very 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 (0.39 to 1.6 in) thick. Seeds are minute, 0.2 millimetres (0.0079 in) long, and attached to a fine hair. When ripe the heads disintegrate into dense cottony fluff, from which the seeds disperse by wind. Typha is often among the first wetland plants to colonize areas of newly exposed wet mud; it also spreads by rhizomes, forming dense stands often to the exclusion of other plants.