Wednesday, December 24, 2014

Tree of Heaven

Tree of Heaven
Ailanthus altissima
The name for this plant seems appropriate for Christmas Eve, however it has a very bad name in our area, being non-native and somewhat invasive. I've not seen it in nature preserves or nicer areas, mostly in the city, vacant lots, cracks between cement and buildings or fences, and other places that only harbor alien, invasive species. There are a number of larger specimens along the Rivergreenway in Fort Wayne, but they don't seem to crowd out other trees and could be easily removed if necessary.

Tree of Heaven is native to China and is a well behaved and welcome plant there. There it is used for wood, medicine, and as a host plant for silkworms. I guess it just depends on your point of view.

Note that the leaflets have a couple of pairs of teeth near the base. These teeth have little glands which have no apparent purpose.
The seed samaras are pretty, colored in greens, pinks and reds. They have a little twirl at the tip, probably an aid to cause it to flutter farther away from the tree as it floats to the ground.
The twig is very stout. The leaf scars are shield shaped
Note the numerous vein scars, the little dots around the inside edge of the leaf scar
The brown pith is more than half the diameter of the twig