Eucommia and its Distributions

Eucommia is a small tree genus now native to China, and the fossil record shows a wider distribution.The monobiotic Eucommia ulmoides is endangered in the wild, but is widely cultivated in China for its bark and is highly valued in herbal medicine, including traditional Chinese medicine.

Descriptions

Modern Eucommia trees grow to about 15 m tall.The leaves are deciduous, alternately arranged, simple ovate, with acuminate tips, 8-16 cm (3.1-6.3 in) long, with serrate margins.If a leaf is torn, latex filaments seep from the veins and solidify into rubber, holding the two parts of the leaf together. It blooms from March to May with inconspicuous, small, green flowers.The fruit ripens between June and November and is a samara very similar in shape to an elm samara.Modern fruits are 2-3 cm (0.79-1.18 in) long and 1-2 cm (0.39-0.79 in) wide, while fruits of extinct species are 21 mm (0.83 in) long.Eucommia is dioecious, with separate male and female plants.

Taxonomy 

Eucommia ulmoides is the only member of the Eucommia family and was previously considered a separate order Eucommia ulmoides. The modern species is sometimes called "Ebonite",[3] "Gutta" or "Chinese Hevea", but is not related to either the true Guta in Southeast Asia or the South Asian Hevea americana.

Eucommia

• Elcommia ulmoides (Miocene-Pliocene; Mexico)

• Eucommia eocenica (Middle Eocene; Mississippi Bend)

• Eucommia europaea (Oligocene; Europe)

• Eucommia jeffersonensis (Late Eocene; Oregon)

• Eucommia montana (early to late Eocene; western North America)

• Eucommia rolandii (Early-Middle Eocene; Mississippi and British Columbia)

• Eucommia ulmoides (live, central and eastern China)

Distributions

E.ulmoides is native to forested areas in the hills and mountains of the central and eastern provinces of China, although the species is thought to be extinct in the wild.E.ulmoides is also occasionally planted in botanical and other gardens in Europe, North America, and elsewhere, where it has gained attention as the only hardy (at least -30 °C) rubber-producing tree.Fossil species of Eucommia have been found in lignite deposits in Central Europe between 10 and 35 million years ago,in many fossil sites in Asia,and five different fossil species have been described in North America, suggesting that the genus was Wider range.