Physiognomy and Structure: The tree layer is dominated by tall (20-35 m in height) single-stemmed deciduous species. The canopy is overlapping, generally forming 60-100% cover. The shrub layer is also dense with up to 60% cover, and often multi-tiered, with both tall and short shrubs. The herbaceous layer is dominated by forbs with up to 20% cover. In parts of this alliance''s range, graminoid cover is primarily from introduced grass species.

Floristics: These forests are codominated by Platanus occidentalis, Populus deltoides, and Salix nigra. Other species that may be present include the understory tree Salix nigra; the shrubs Ilex vomitoria and Malvaviscus arboreus var. drummondii (= Malvaviscus drummondii); the graminoids Carex cherokeensis, Chasmanthium sessiliflorum, and Oplismenus hirtellus ssp. setarius (= Oplismenus setarius); and the forb Conyza canadensis.

Dynamics:  Cottonwood forests grow within an alluvial environment that is continually changing due to the dynamics of the river. This riparian vegetation is constantly being "re-set" by flooding disturbance. The process of cottonwood regeneration is well-documented. Periodic flooding events can leave sandbars of bare, mineral substrate. Cottonwood seedlings germinate and become established on newly-deposited, moist sandbars. In the absence of large floods in subsequent years, seedlings begin to trap sediment. In time, the sediment accumulates and the sandbar rises. The young forest community is then above the annual flood zone of the river channel. In this newly-elevated position, with an absence of excessive browsing, fire, or agricultural conversion, this cottonwood community can grow into a mature riparian forest. At the same time, the river channel continually erodes streambanks and creates fresh, new surfaces for cottonwood establishment. This results in a dynamic patchwork of different age classes, plant associations and habitats.