ash-leaved maple

Acer negundo

Smooth trunk and compound leaf
Close-up male flowers
Male flowers blowing in the wind
Female flowers
Samaras taking shape
Maturing samaras
mature samaras and compound leaf

The existence of so many other common names for the ash-leaved maple in North America indicates how widespread this native tree is.  It is the only North American maple with compound leaves.  Unlike most other native maples, it is a dioecious species.  This means a given tree has either male flowers or female flowers but not both.  Consequently, seed production depends on whether female trees are positioned to capture the wind-borne pollen from male trees.  The two male and three female ash-leaved maples at Salter Grove are relatively distant from one another but grow in relatively open habitats where pollen dispersal and capture have occurred successfully to result in seed production.  

Despite the reproductive impediment, the ash-leaved maple has been naturalized in Europe, Asia and even Australia.  It is a relatively short-lived but fast-growing tree that is sometimes considered an invasive species because of its large seed crops and ability to grow quickly in disturbed and natural habitats where water is plentiful.