Jack Dykinga / Morning light with autumn coloured Cottonwoods (Populus sp) trees lining the river. Valley of the Gods, Colorado Plateau, of the Great Basin Desert, Utah, USA, November 2018.

Andres M. Dominguez / Hawthorn berries (Crataegus monogyna) in Poplar woodland (Populus) Sierra de Grazalema Natural Park, southern Spain. October.

Jack Dykinga / Lower Calf Creek Falls with Boxelders {Acer Negundo} and Cottonwoods {Populus fremontii) in the foreground, autumn colours, Grand Staircase - Escalante National Monument, Utah

Jack Dykinga / Morning light with autumn coloured Cottonwoods (Populus sp) trees lining the river. Valley of the Gods, Colorado Plateau, of the Great Basin Desert, Utah, USA, November 2018.

Jack Dykinga / Morning light with Cottonwoods trees in autumn the river with with sagebrush and rabbitbrush in the forground. Valley of the Gods, Colorado Plateau, Great Basin Desert, USA.

Jack Dykinga / Morning light with autumn colored Cottonwoods (Populus) trees lining the riverside with Sagebrush (Artemisia) and Rabbitbrush in the foreground. Valley of the Gods, Colorado Plateau, Great Basin Deser...

Jack Dykinga / Navajo Dome at dawn with autumn coloured Cottonwoods (Populus) lining the Fremont River Capitol Reef National Park, Utah, USA, October 2017.

Jack Dykinga / Quaking aspen (Populus tremuloides) in autumn colours with tree trunks behind, Dixie National Forest, Utah, October.

Jack Dykinga / Freemont cottonwood trees (Populus fremontii) in autumn, Capitol Reef National Park, Utah, America, October.

Jack Dykinga / Freemont cottonwood trees (Populus fremontii) along river, Capitol Reef National Park, Utah, USA, October 2016.

Andres M. Dominguez / Poplar trees (Populus sp) in autumn, Sierra de Grazalema Natural Park, southern Spain, October.

Loic Poidevin / Poplar tree (Populus) covered in Mistletoe (Viscum album) and surrounded by water of Lake Grandlieu in winter, West France

Jenny E. Ross / Snow-covered cottonwoods, South Yuba River. Sierra Nevada Mountains, California, USA. February 1998.

Tim Fitzharris / The Watchman, outcropping near south entrance of Zion National Park, cottonwoods in foreground, Utah

Tim Fitzharris / Mitten Rock with autumn colored cottonwoods and blooming desert shrubs, New Mexico

LYNN M. STONE / Cottonwoods and Mount McKinley after snow. Denali NP, Alaska

LYNN M. STONE / Cottonwoods and Mt McKinley in snow. Denali NP Alaska USA

Jack Dykinga / Cottonwoods in autumn in the ponds of the refuge in evening light with reflections in the rising water level, near the Colorado River, Cibola National Wildlife Refuge, Arizona, USA. November 2020.

Jack Dykinga / Cottonwoods in autumn in the ponds of the refuge in morning light with reflections in the rising water level, near the Colorado River, Cibola National Wildlife Refuge, Arizona, USA. November 2020.

John Shaw / Autumn quaking aspen trees (Populus tremuloides) below Turret Ridge, Uncompahgre National Forest, Colorado, USA. October.

John Shaw / Autumn quaking aspen grove (Populus tremuloides) with trunks scarred by browsing elk (Cervus canadensis). Below Turret Ridge, Uncompahgre National Forest, Colorado, USA. October.

John Shaw / Autumn quaking aspens (Populus tremuloides) with mixed evergreens below the Sneffels Range. Uncompahgre National Forest, Colorado, USA. October.

John Shaw / Narrowleaved cottonwood trees (Populus angustifolia) in autumn color mark a wet area on the prairie. Montana, USA. October.

Jack Dykinga / Aspen (Populus tremuloides) forest with scattered Englemann spruce (Picea engelmannii) in autumn, Hayden Mountain in background. Uncompahgre National Forest, Colorado, USA. September 2019.

Jack Dykinga / Aspen (Populus tremuloides) tree trunks in autumn. Uncompahgre National Forest, Colorado, USA. September 2019.

John Shaw / Cottonwood trees (Populus sp) in autumn color and weathered granite boulders, in the Alabama Hills, California, USA, November.