Willow Family (Salicaceae). Fremont’s cottonwood is a native tree growing in riparian areas near streams, rivers and wetlands in the American Southwest. Fremont's cottonwood trees range from 12 to 35 meters in height, and trunk diameter ranges from 0.30 to 1.5 meters. The bark is smooth in younger trees, becoming deeply furrowed with whitish cracked bark with age. The leaves are cordate (heart-shaped) with white veins and coarse crenate-serrate teeth on the margins. The leaves have petioles 1/2 to equal the blade length, laterally compressed near the blade which causes the leaves to flutter in the wind. These trees are dioecious, with flowers in drooping catkins, which are 4 to 14 cm long. Cottonwoods bloom from March-April. The fruit is an achene, which is attached to a silky hair, en masse looking like patches of cotton hanging from the limbs, thus the name cottonwood. The seeds are wind dispersed.