144420 Aspen Populus tremulus Salicaceae Height to 18m. Slender tree with a rounded crown. Suckers readily. Bark Ridged and fissured with age. Leaves Rounded to oval, with shallow marginal teeth, palest below; rustle in the slightest breeze and turn golden in autumn. Reproductive parts Reddish male catkins and greenish female catkins on different trees. Status Common on poor, damp soils.