Hardy Rubber Tree

Eucommia ulmoides is a small tree, about 15 metres tall, native to China, and the only living species of its genus and of the family Eucommiaceae. Its leaves are alternate, ovate and serrated, and if one is torn across, strands of latex from the veins harden into rubber and hold the halves together. The fruit is a winged one-seeded samara resembling an elm's. It is sometimes called the gutta-percha tree or Chinese rubber tree, but is related to neither the true gutta-percha tree nor the South American rubber tree. It is the only cold-tolerant rubber-producing tree, hardy to at least minus 30 degrees Celsius. It is widely cultivated in China for its bark, which is highly valued in herbology, and as one of the 50 fundamental herbs of Chinese herbology, where it is called dùzhòng. The geniposidic acid it contains is an iridoid glucoside. It is considered vulnerable in the wild.