logo features a large moose standing under the canopy of a moosewood tree .
The Only Non-Asian Snakebark Maple Linnaeus gave this Acer its species name and managed to misspell it , too , as the name is a reference to Pennsylvania , one of the states where the tree grows wild .
The smooth , striped , reptilian-like bark on Acer pensylvanicum puts it in a taxonomic section of the genus Acer called Macrantha , the snakebark maples . This group is made up of about 20 species , and A . pensylvanicum is the only one of them that ’ s found in North America . The rest are restricted to eastern Asia . You ’ ll find stunning specimens of many of the snakebark maples in the Dan Hinkley Asian Maple Collection at the Arboretum , including Honshu maple ( Acer rufinerve ) from Japan and Kawakami maple ( Acer caudatifolium ) from Taiwan .
Adapted to Shade An understory tree , Acer pensylvanicum grows in moist forests in its home range , preferring shaded slopes and valleys . It is among the most shadetolerant of deciduous trees and will actually suffer if planted in full sun . In the wild , the tree can get up to 40 feet high and more , but in cultivation , striped maple typically reaches a height of 15 to 25 feet and a spread of 12 to 20 feet .
The leaves are large for a snakebark maple , growing up to seven inches long . Each one has three lobes and resembles the shape of a goose ’ s foot , giving the tree another one of its common names : goosefoot maple . The foliage emerges in spring with a pink hue , turns to dark green by summer , and then changes to bright yellow in the autumn before dropping . Yellow flowers on six-inch racemes appear in May , followed by winged samaras .
Recent research has shown that the species is a sequential hermaphrodite , meaning that it can change its sex during its lifetime to bear either male or female flowers . Why would a tree do this ? One possible scenario is that a dying or sick male tree switches its flowers to female so that it can produce offspring as quickly as possible .
The young specimen in the tree peony collection along Arboretum Drive .
In the Arboretum The Washington Park Arboretum has several specimens of Acer pensylvanicum . The oldest dates to 1944 and can be found at the top of the Hybrid Rhododendron Garden , at the western edge of the Asian Maple Collection . The tree has had a hard life , losing part of its trunk in a windstorm , with the remaining trunk nearly horizontal now . However , it is still producing new , colorful branches and putting on a lovely fall foliage display .
The rest of the specimens are young ( under 20 years old ) and in good shape . Two are nearby , just south of the Magnolia Collection , along the upper Lookout Loop Trail . Dating to 2009 , they came to us from the Rhododendron Species Botanical Garden . Another easy one to find is the specimen growing among the tree peonies along Arboretum Drive . This specimen , and another nearby , date to 2006 and came to us from the Arnold Arboretum .
In the home garden , striped maple is a great small tree for a moist , partially shaded spot . It will even tolerate deep shade , but will make a break for it if an overhead space opens up . The fascinating bark adds winter interest to a woodland garden , and the yellow fall color adds a bright note to gray Northwest skies . m
Phil Wood is a garden designer and writer and serves on the “ Arboretum Bulletin ” Editorial Board . Visit his website at www . philwoodgardens . com .
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