Pterocarya

Pterocarya are a genus of plants in the Juglandaceae family. Pterocarya comes from the ancient Greek πτερο- "ala" + κάρυον "walnut", native to Asia.

Description

They are deciduous trees, 10-40 meters tall, with pinnate leaves 20-45 cm long, with 11-25 leaflets. The branches have compartmentalized piths, a characteristic shared by the genus Juglans, but not by the genus Carya, the pecans, of the same family Juglandaceae.

Flowers are monoecious, in catkins. The seed-bearing catkins when mature (about 6 months after pollination) are pendulous, 15-45 cm long, with 20-80 seeds hanging along them.

The seeds are small nuts 5-10 mm wide, with two wings, one on each side. In some of the species the wings are short (5-10 mm) and broad (5-10 mm), in others longer (10-25 mm) and narrower (2-5 mm).

Species

There are six species of pterocaria:

• Pterocarya fraxinifolia - Caucasus and Elburz mountains in southwest Asia.
• Pterocarya hupehensis Slan - China Center.
• Pterocarya macroptera - West and southwest of China.
• Pterocarya rhoifolia - Japan, East China (Shandong).
• Pterocarya stenoptera C. DC. - China, scattered.
• Pterocarya tonkinensis - South Extreme China (Yunnan), Indochina.

Another species from China, with similar foliage and an unusual circular ring just around the nut (instead of two wings on the sides), previously listed as Pterocarya paliurus, has now been transferred to a new genus, as Cyclocarya paliurus.

Uses

Pterocaria are large, fast-growing trees, occasionally planted in parks and large gardens. The most cultivated outside of Asia is P. fraxinifolia, together with P. rhoifolia. The hybrid P. x rehderiana, a cross between P. fraxinifolia and P. stenoptera, is even faster growing and has occasionally been planted for timber production. The wood is of good quality, similar to walnut, although not as dense or strong.