American Sweetgum – Liquidambar styraciflua

05 Dec

Our plant of the month this month is a tree, adorned with delightful fall colors these days: the American Sweetgum, Liquidambar styraciflua.

Liquidambar styraciflua originates in Eastern United States, where it embellishes the broad-leafed deciduous forests with its gorgeous colors. The meaning of the Latin name – Liquidambar – is Liquid Amber, and the specific epithet – styraciflua – means flowing with gum. And indeed, this tree has liquid resin (or gum), used for cooking and perfume making. This resin gave the tree its common English name – Sweetgum.

The Liquidambar is a deciduous tree, up to 25 m tall. When the tree is young, its crown is pyramidal. When it grows older, the crown is more rounded-oval. The tree’s bark is deeply ridged, and resembles a reptilian skin – giving the tree another common name, Alligator wood.

The leaves are star-shaped, palmate, usually with 5 lobes, but sometimes less (3) or more (7). Their size is 6-12 cm, and when bruised give a sweet resinous fragrance. During summer, the leaves are vivid-green, but as the seasons change and autumn arrives, the leaves change their colors to fall colors. Fall color at its best is a brilliant mixture of yellows, oranges, purples and reds. In colder regions, where the trees might suffer an early frost – the frost sometimes causes the tree to shed all its leaves without changing colors. On the opposite end, in the warmer regions, the tree changes its behavior and becomes evergreen, with no significant fall colors.

The flowers bloom in spring – around April. The Liquidambar has small, inconspicuous, yellow-green flowers. The flowers are pollinated by the wind, as in many other trees. It is monoecious, yet the flowers are unisexual – Male and female flowers appear on separate branches of the same tree. Female flowers turn into fruit – globose spiked seed capsules, up to 4 cm across, they are commonly called “Gumballs”.

The tree’s resin thickens easily, and has many uses. It is used to produce a stabilizing cooking agent (a vegan substitute to gelatin) and also chewing gum. It has a sweet fragrance, so it was used in the incense and perfumes industry. The resin is also used for a variety of popular medicines – it is considered to be antiseptic, carminative, diuretic, expectorant, parasiticide, poultice, salve, sedative and vulnerary, and was used both internally (by chewing) and externally (applied on the skin).

In nature, 400 years old Liquidambar trees were found, 40 m tall and with a 90 cm diameter trunk. In our garden the trees are smaller – but their fall colors attract the eye from afar. We highly recommend visiting the America section of the garden during this season, to admire the many fall colors of the Liquidambar, as well as of other trees that have fall colors during this season.

Written and photographed by: Yael Orgad, December 2018

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