Trichothallic growth is growth in which cell division is restricted to the base of one or several filaments. This method of growth is exhibited in members of the genus Desmarestia, including both D. ligulata and D. viridis. To the left are pictures of trichothallic growth toward the apex of a branch. Each apex ends with a single filament having a intercallary meristem which produces lateral filaments above and below it. This same type of meristem occurs at the apices of all the laterals and thus the entire thallus is fringed with pigmented hairs emerging distally from the meristems. These hairs are conspicuous and grow rapidly when the thallus is young but are usually shed by the time the plant is older. This pattern of growth is an example of pseudoparenchymatous tissue.