A genus ( tribe ) including 10 trees + related Platyclada. All are native to temperate regions of Asia though are easily grown in North America and Europe.
The large pinnate leaves appear early in spring but unfortunately often dont show much color in the autumn. They are excellent shade trees, typically unblemished, leafy and verdant green all summer long.
They prefer deep, fertile, moist well drained soil in full sun.
Can be propagated from cuttings, suckers or seed which should be soaked in water for 24 hours before sowing.
Platyclada stobilacea ( Coned Wingnut )
A medium to large sized, dome canopied tree reaching 60 feet or more that is native to China, Korea and Japan. Some records include: fastest recorded growth rate - 3 feet; largest on record - 80 x 40 feet with a trunk diameter of 3 feet. A large tree grows at Arnold Arboretum in Boston, MA.
The pinnate leaves up to 12 inches in length are composed of up to 7 top 15 ( rarely up to 23 ) taper pointed, sharply toothed leaflets up to 5 x 1 inch in size. The leaflets are unstalked and are hairy at first becoming smooth on both sides. The handsome foliage is deep green in summer turning to yellow in autumn.
The flowers are yellow upright catkins botn in clusters at the branch tips in summer.
They are followed by brown, conelike fruits up to 1.5 inches in length that persist over the winter.
Hardy zones 5 to 9 and prefers deep, rich, well drained, moist soil in full sun.
Heat tolerant and thrives in much of the eastern U.S.
* photo taken on May 1 2010 @ U.S. National Arboretum
* photo taken on October 17 2010 @ U.S. National Arboretum, D.C.
Pterocarya fraxinifolia ( Caucasian Wingnut )
Native from northern Iraq to the Caucasus though often planted over much of Europe; this is a very large, fast growing, dome canopied tree to 100 feet in height or often more. Some records include: fastest recorded growth rate - 6 feet with 1.5 inch trunk diameter increase; 10 years - 50 x 30 feet; 20 years - 82 feet; 230 years - trunk diameter of 8 feet; largest on record - 130 x 117 feet with a trunk diameter of 8 feet.
Some very large trees grow at Cave Hill Cametary in Louisville, KY; Monticello in Charlottesville, VA ( diameter 7.5 feet ) and Brooklyn Gardens in New York City.
The Caucasian Wingnut is an excellent shade tree.
The leaves are up to 28 inches in length and are composed of 11 to 27 shiny deep green leaflets up to 9 x 2 inches that turn to yellow in autumn.
The leaf rachis is not winged.
The flower catkins are yellow-green to yellow and up to 20 inches long and weeping.
The decorative fruits are small and winged along hanging catkins up to 20 inches in length.
The bark is smooth and whitish gray becoming deeply furrowed as the tree ages.
Hardy zones 4 to 9 and likes moist soil.
* photos taken by Milan Havlis, owner of central Europes premier plant nursery
Pterocarya macroptera
A medium size tree native to China that can reach a maximum size of 82 feet with dark brown bark. The leaves are huge and tropical looking and reach up to 64 inches in length. They are composed of up to 13 leaflets up to 10 inches in length.
Hardy north to zone 5b
Pterocarya paliurus ( Roundleaf Cyclocarpa )
A tall tree native to southern China that can reach a maximum height of 100 feet. The leaves up to 10 inches long are composed of up to 11 oblong leaflets up to 6 x 2 inches in size. The flower clusters are up to 10 inches in length. Hardy north to zone 6
Pterocarya x rehderiana ( Hybrid Wingnut )
The hybrid between Pterocarya fraxinifolia & P. stenoptera. This is one of the fastest growing of all deciduous trees and can easily exceed 100 feet with a broad spreading canopy. Some records include: fastest recorded growth rate - 8 feet; 17 years - trunk diameter of 2 feet; 17 years - 2 feet in trunk diameter; 20 years - 82 feet; 30 years - 2.7 feet in trunk diameter; 40 years - 100 feet tall; 50 years - 3.5 feet in trunk diameter; largest on record - 130 x 70 feet with a trunk diameter of 8 feet. A very handsome tree, it grows with a massive lushly foliaged domed canopy.
The leaves up to 18 inches in length are composed of 11 to 21 glossy deep green, untoothed leaflets that turn to yellow in autumn. The leaf rachis has wings that are narrow and upright.
The leafstalks are winged.
The long drooping catkins appear in early spring and later turn into a long string of "wingnuts" up to 18 inches long.
The purple-brown bark has interlacing ridges and pale orange fissures.
Hardy zones 5 to 9 and is very drought tolerant. Prefers deep, rich well drained soil and can sucker heavily in sandy soil. Propagated either from suckers in autumn or softwood cuttings in summer.
Pterocarya rhoifolia ( Japanese Wingnut )
A very large, dome shaped, handsome shade tree native to Japan that can reach 80 feet or more. Some records include: fastest recorded growth rate - 5 feet; 20 years - 66 feet; largest on record - 100 x 50 feet with a trunk diameter of 7 feet. A massive tree 70 feet tall with a trunk diameter of 6.6 feeet is reported to grow at the Hort Station west of St. Catherines, Ontario.
It is a popular street tree in China and has handsome foliage but invasive roots.
The leaves up to 20 inches in length are composed of 11 to 21 leaflets up to 5 inches long. The taper pointed, leaflets are oval with finely serrated margins. They are finely downy at first turning smooth and glossy medium green in summer then to yellow in autumn. The leaf rachis is not winged and the leaflets are unstalked.
The fruits are green winged small nuts stringed along hanging catkins up to 20 inches long.
The vertically fissured bark is dark gray.
Hardy zones 4 to 9. Flood tolerant and an excellent tree for use on flood plains. Highly recommended in the Midwest as an Ash substitute.
* photos taken on May 1 2010 @ U.S. National Arboretum, D.C.
Pterocarya stenoptera
The Chinese Wingnut is rare in the U.S. but is one of my very favorite large shade trees which can add a very tropical look to the temperate landscape. It is a native of China and grows very fast and may reach 25 x 25 feet tall with a diameter of 14 inches in only 6 years. In 20 years it may reach 82 feet however not get much taller. Old trees tend to be very massive, sturdy and heavy set and have been known to reach 100 x 80 feet with a trunk diameter of 9 feet! The largest known tree in Pennsylvania grows at Westtown School near Philly. The Chinese Wingnut can live up to 400 years.
The leaves are pinnate and up to 18 inches long and composed of 11 - 25 bright green ( downy at first ) leaflets up to 6 x 2 inches. The foliage often turns yellow in autumn. The central stalk is winged.The Wingnut is usually early in leaf.
The fruits are winged and borne in a pendant stalk to 15 inches in length ripening in fall.
The bark is brown with deep fissures.
This tree is hardy from zones 3b - 9 ( -36F ) and can tolerate temporary flooding. It thrives over most of temperate North America, even in harsh South Dakota as well as hot humid northern Florida. The prefer deep, rich, well drained soil in full sun and are best trained to a central leader when young. They can be raised from seed but are also easily raised from cuttings taken in June and planted out in fall when they are 12 inches tall.
Most people in the U.S. have never seen this tree however it is truly beautiful and should be used more especially on floodplains and in parks.
* photo taken on April 11 2010 @ U.S. National Arboretum
* photos taken on 4th of July 2010 @ U.S. National Arboretum, D.C.
* photos taken on July 17 2010 @ Morris Arboretum, Philly, PA
* photos taken on August 3 2010 @ University of Guelph Arboretum, Ontario
subsp Brevifolia
a shorter leaf composed of fewer leaflets.
Pterocarya tonkinensis ( Tonkin Wingnut )
A large shade tree reaching a maximum size of 100 feet that is native to Vietnam, Laos and Yunnan Province in China. Very fast growing, it can reach up to 13 feet in 3 years.
The leaves up to 8 inches in length are composed of up to 20 leaflets up to 7 x 3 inches in size.
Hardy north to zone 7 and thrives in the hot humid summers of the southeast U.S.
Flood tolerant.