Ailanthus altissima (Tree of heaven)

Ailanthus altissima (Mill.) Swingle

Tree of heaven, ailanthus, Chinese sumac, paradise-tree, copal tree, stinking sumac, varnish tree

Kingdom	Plantae	Plants, but not fungi, lichens, or algae
Subkingdom	Tracheobionta	Vascular plants—plants with a “circulatory system” for delivering water and nutrients
Division	Magnoliophyta	Flowering plants, also known as angiosperms
Class	Magnoliopsida	Dicotyledons—plants with two initial seed leaves
Subclass	Rosidae	Roses, legumes, proteas, dogwoods, hydrangeas, mistletoes, euphorbias, grapes, many more
Order	Sapindales	Includes citrus; maples, horse-chestnuts, lychees and rambutans; mangos and cashews; frankincense and myrrh; mahogany and neem
Family	Simaroubaceae	A small mostly tropical family including Quassia, Simarouba, and Ailanthus
Genus	Ailanthus	From a Moluccan name ailanto meaning “sky tree”
Species	altissima	Very tall, tallest

About plant names...

This Chinese native plant was introduced to Philadelpha, PA in 1784. It was extensively planted during the 1800s, establishing it widely through much of North America. It prefers moist, loamy soils, but tolerates a wide range of conditions, with the exception of flooding. It is so tolerant that it is used even to reclaim strip mined soils. The moniker “tree of heaven” is a bit ironic, considering that the name refers to its height, which is rather average for trees. And it is so robust in so many habitats that it is frequently considered one of the worst invasive species in Europe and North America. It secretes a toxin that poisons other plants. “Tree of hell” might be more apt. If you’re thinking of planting one on purpose, please don’t.

Plants: This deciduous tree lives fast and furious, growing rapidly to heights of 56-89' (17-27 m), rarely living more than 50 years. It produces suckers that creates clones, though, so it propagates quickly. Bark is smooth and light gray, with a texture a bit like a cantaloupe. Leaf scars on branches are heart-shaped. Twigs have a light brown pithy interior, similar in texture to styrofoam. Wood is weak, breaking easily in storms.

Leaves: Alternate, even pinnate or odd pinnate, 12-35" (30-90 cm) long, with 10-41 leaflets. The rachis, or stem between the leaflets, is light green to reddish. Leaflets are ovate to lanceolate, with minutely toothed edges. The leaves smell bad when crushed.

Flowers: Panicles up to 20" (50 cm) are dotted with small yellowish-green to reddish flowers. Male and female flowers appear on different trees, making this species dioecious. Flowers appear from May to July.

Fruits: Samaras, gold or reddish colored twisted wings, each containing a seed, are oblanceolate in shape. Samaras occur in dense clusters, with each one 1-2" (2.5-5 cm) long and about ¼-½" (6.3-12 mm) wide. They persist through winter. A single female tree can produce 300,000 seeds annually, and the wings help to propel them far and wide.

Medical: Although used as an astringent in traditional Chinese medicine, tree of heaven can be toxic to domestic animals and cause allergic reactions for some people.

Online References:

Ailanthus altissima on www.srs.fs.usda.gov

Ailanthus altissima on Wikipedia

Ailanthus altissima at the Missouri Botanical Garden

Ailanthus altissima on plants.ces.ncsu.edu

Ailanthus altissima on extension.psu.edu

Ailanthus altissima on www.nature.org