Manitoba maple

Manitoba Maple (Acer negundo), also known as Ash-leaved Maple or (confusingly!) Boxelder, is a species of maple, which occurs throughout most of North America. It is a small tree that grows up to 10-20m tall. Unlike most other maples (which usually have palmate leaves), it has pinnate leaves with 3, 5 or 7 leaflets, resembling an Ash or an Elder, hence the two alternative common names.

A few botanists treat it in its own distinct genus, as Negundo aceroides, but this is not widely followed.

There are two subspecies:

• The typical subspecies Acer negundo subsp. negundo, the Typical Boxelder or Ash-leaved Maple, with hairless shoots and leaves, in most of its area: southeast British Columbia east to southern Ontario and New Hampshire, and south to eastern Nevada, Arizona, northernmost Mexico and southeast to Florida
  • Some authors further subdivide subspecies negundo into a number of regional varieties, but these intergrade and their maintenance as distinct taxa is disputed by many.

• The western subspecies Acer negundo subsp. californicum, or California Boxelder Maple, with pubescent (finely hairy) shoots and leaves; a disjunct population in the Central Valley area of California