Beautiful cherry blossom and willow in Ueno Park, Tokyo, Japan, Asia

A light-filled elementary classroom. A white ceiling reflects light from the windows above. Traditional building methods and materials, such as the poplar and willow ceilings are combined with modern solar and passive solar technology. Druk Padma Karpo Institute. Shey, Ladakh, India

A light-filled elementary classroom. A white ceiling reflects light from the windows above. Traditional building methods and materials, such as the poplar and willow ceilings are combined with modern solar and passive solar technology. Druk Padma Karpo Institute. Shey, Ladakh, India

A light-filled elementary classroom. A white ceiling reflects light from the windows above. Traditional building methods and materials, such as the poplar and willow ceilings are combined with modern solar and passive solar technology. Druk Padma Karpo Institute. Shey, Ladakh, India

White willow (Salix alba) tree with base of trunk almost chewed through by Eurasian beaver (Castor fiber), Narew marshes, Podlaskie, Poland. MORE INFO: Beaver activity is crucial in keeping Poland's ancient marshes open and free of encroaching bushes and trees and their dams also help to maintain high water levels.

Hoarfrosted pollarded willow, Naturschutzgebiet Wuemmewiesen nature reserve, Bremen, Germany, Europe

Willow Ptarmigan (Lagopus lagopus)

Willow trees with white frost, typical south-Swedish tree-lined road, TÂnebro, SkÂne, Sweden, Europe

White willow (Salix alba) on a sandbank, dawn, shore, water, summer, Bondensee, Bregenz, Vorarlberg, Austria, Europe

Close-Up Of Male Willow Ptarmigan Changing From Winter To Breeding Plumage Near Savage River, Denali National Park & Preserve, Interior Alaska, Spring

Close-up portrait of a male willow ptarmigan (Lagopus lagopus) showing early breeding colors in its neck and eye combs, surveying its high-country territory in Southcentral Alaska's Chugach Mountains on an April day. The head and neck will become completely chocolate-brown as the bird's breeding colors develop, Alaska, United States of America

Willow Ptarmigan male (Lagopus lagopus) turning into his summer colours from his white winter's coat, Denali National Park and Preserve; Alaska, United States of America

Willow ptarmigan (Lagopus lagopus) in full-white winter plumage watches for danger on a bright February day, Anchorage, Alaska, United States of America

Close-up portrait of a Willow ptarmigan (Lagopus lagopus) in full-white winter plumage watching for danger on a bright February day, Anchorage, Alaska, United States of America

Willow Ptarmigan (Lagopus Lagopus) In Plumage Transition From Brown Summer Color To White Winter Color

Willow Ptarmigans (Lagopus lagopus) standing in snow with white winter plumage in Arctic Valley, South-central Alaska, Alaska, United States of America

Polar Bears (Ursus Maritimus) Sparring In The Snow During Winter Near Churchill, Manitoba, Canada

Large Male Polar Bear (Ursus Maritimus) Sitting In The Willow Bushes Near Churchill, Manitoba, Canada

Willow ptarrmigan (Lagopus lagopus) in winter plumage in the snow, James Bay, James Bay, Province of Quebec, Canada

View of cotton grass bloom in Teufelsmoor, Bremen, Germany

View of houses and fields in village Ceylon on highway 6 South, Saskatchewan, Canada