Sweetgum

Liquidambar formosana
Liquidambar orientalis
Liquidambar styraciflua

The sweetgums Liquidambar are a genus in the witch-hazel family Hamamelidaceae, with three species of large deciduous trees, 25-40m tall, with palmately lobed leaves:

• Liquidambar formosana - Chinese Sweetgum (central & southern China, Taiwan).
• Liquidambar orientalis - Oriental Sweetgum (Asia Minor).
• Liquidambar styraciflua - American Sweetgum (eastern North America from New York to Texas and also eastern Mexico to Guatemala).

They are popular ornamental trees, particularly in warm-temperate areas with hot summers, being some of the most reliable trees for good autumn (fall) colours in these conditions.

The genus was much more widespread in the Tertiary, but has disappeared from Europe due to extensive glaciation in the north and the Alps, which has served as a blockade against southward migration. It has also disappeared from many parts of North America due to climate change, and even from the unglaciated (but nowadays too cold) Russian Far East. There are very many fossil species of Liquidambar, showing its relictual status today.

External links

• Deterministic Plio-Pleistocene extinctions in the European cool-temperate tree flora. Ecology Letters 6 (7): 646-653, July 2003