The foliage turns from emerald during spring and summer to red, reflecting the seasonal change to autumn and winter. The change in foliage colour is due to other pigments inside apart from chlorophyll, with both reacting differently to changing climate and environmental conditions. The larger the temperature difference and the longer the duration, the more obvious the colour change. While located in the subtropical region, Hong Kong has many parks planted with those trees reflecting seasonal changes, such as Sweet Gum (Liquidambar formosana) in the family Hamamelidaceae, a native species to Hong Kong which can grow as tall as 30 metres. Besides, foliage of Bald Cypress (Taxodium distichum) and Water Pine (Glyptostrobus pensilis) in the family Taxodiaceae, with both growing up to 40 metres and 25 metres respectively, will also be turning orange brown before falling down.