Saturday, April 10, 2010

Pterostyrax

A genus of 3 very attractive landscape plants that are closely related to the Styrax.
Prefers deep, moist, well drained, fertile, acidic, sandy loam in sun to partial shade on a site sheltered from excessive wind. Sounds complicated but your average woodland understory conditions will do. The Pterostyrax's are tolerant of summer heat, drought as well as smog. They are not prone to pests or diseases and are easy to grow from half hardened cuttings. Can also be grown from seed.
The Pterostyrax's are not normally bothered by pests or disease.
They transplant well if moved while small and in late fall or winter.

Pterostyrax corymbosa
A fast growing, small tree reaching around 40 feet that is native to far eastern China & Japan. Some records include: 2 years - 7 feet; 10 years - 20 x 20 feet; largest on record - 56 x 41 feet with a trunk diameter of 1.7 feet. This tree is rare though should be planted much more often.
The bristly-toothed leaves, up to 8 x 4.5 ( rarely over 5 ) inches in size, are deep green, turning to yellow during autumn.
The fragrant, small, white, bell-shaped flowers are borne on clusters up to 10 inches in length in spring.
The attractive exfoliating bark is glossy brown.
Hardy from zones 5 to 9 ( reportedly in zone 4 and should be tested more ) and is heat tolerant.

* photo taken on May 8 2010 @ U.S. National Arboretum, Wash. DC

* photos taken on Sep 3 2017 @ U.S. National Arboretum, D.C.


Pterostyrax hispida ( Epaulette Tree )
A vigorous, broadly spreading, small to medium-size tree reaching around 30 feet or more, that is native to China and Japan. Some record include; fastest recorded growth rate - 5 feet; 5 years - 15 feet; 8 years - 20 feet; 20 years - 40 x 37 feet; largest on record - 56 x 60 feet with a trunk diameter of 2.3 feet.
The minutely-toothed, pointed-oblong to obovate leaves are up to 8 x 4 ( rarely 11.5 x 6 ) inches in size. The tropical-looking foliage is smooth mid-green above, hairy silvery beneath; turning to yellow during autumn.
The small ( 0.25 inch ) creamy-white, fragrant flowers are borne in drooping panicles up to 10 x 4 inches in size during early to mid summer.
The flowers are followed by hairy gray fruits up to 0.5 inches in length which last until January.
The light gray to pale brown bark is corky with orange fissures.
Hardy zones 4 to 8. Tolerates -27 F with no damage. It is fully hardy at zone 4b Dominion Arboretum in Ottawa, Canada. It tolerates temporary flooding and is often found on floodplains in the wild.

* photos taken on July 17 2010 @ Morris Arboretum, Philly, PA






* photos taken on July 26 2015 @ Niagara Parks Bot. Gardens, Niagara Falls, ON

* photo taken by Milan Havlis, owner of central Europe's premier nursery

* photos taken on Jul 18 2017 @ Dominion Arboretum, Ottawa, ON

* photo taken on Sep 3 2017 @ U.S. National Arboretum, D.C.

* historic archive photo


Pterostyrax psilophylla
An attractive, very fast growing, medium sized tree native to central China that is endangered with extinction in the wild. Some records include: fastest recorded growth rate - 3 feet; largest on record - 82 x 40 feet with a trunk diameter of 1.5 feet.
The attractive foliage appears early in spring and is mid-green above, hairy grayish-white beneath. The oblong leaves are up to 9 x 5 inches in size.
The white flowers are borne on panicles up to 6 inches in length, during late spring.
The bark is dark brown.
Hardy zones 6 to 8 ( reports of 5 ).

* photos taken July 4 2010 @ U.S. National Arboretum, D.C.


* photos taken on Apr 24 2016 @ U.S. National Arboretum, DC


Pterostyrax xylocarpum ( Chinese Parasol Storax )
Also called Melliodendron xylocarpum and Woodyfruit Melliodendron. A rare, moderate growing, dense, large tree that in the one and only member of the genus Melliodendron that is native to central and southern China and reaches up to 50 x 30 feet. Some records include: 15 years - 27 feet ( average ); largest on record - 66 feet.
The oblong to elliptic, papery leaves are up to 8.5 x 3 inches in size.
The foliage is bright green, appears very early in spring and persists very late in autumn. In mild climates, the foliage may become semi-evergreen.
The very showy, wide opening white flowers are up to 2.8 inches across, borne during early spring with the emerging foliage. The flowers sometimes open pink before turning to white. This is among the most beautiful of all flowering trees and rivals the best Flowering Dogwoods.
The woody pear-shaped fruits are up to 3 x 1.6 inches in size ripening during mid-summer and lasting to mid-autumn.
The bark is gray-brown and exfoliating. The shoots are gray-brown with ovate winter buds up to 0.4 inches in length.
Hardy zones 7 to 9, it is tolerant of hot humid summers such as occur in its native range but also thrives in the Pacific Northwest. Preferring partially shaded woodland conditions, it prefers deep, fertile, moist, well drained soil. It does not tolerate poorly drained clay soils. Generally pest and disease free. Propagation is easy from cuttings band also from seed.

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