The Paperbark Maple (Acer griseum), also known as the Blood-Bark Maple is a species of flowering plant in the family Sapindaceae, native to central China. Acer griseum is found in the Chinese provinces of Gansu, Henan, Hubei, Hunan, Shaanxi, Shanxi and Sichuan. It is one of many species of maples widely grown as ornamental plants in temperate regions.
The most interesting feature of these maple is its exfoliating bark. Particularly on mature trees, the bark peels back in thin, papery curls, revealing a cinnamon-red color underneath. Translucent pieces of which often stay attached to the branches until worn away. This exfoliating bark provides year-round visual interest, especially in winter when other trees have bare branches. It also has spectacular autumn foliage which can include red, orange and pink tones.
Paperbark Maples are relatively small, growing to a height of 20 to 30 feet (6 to 9 meters) and a width of 15 to 25 feet (4.5 to 7.5 meters). They thrive in USDA zones 4 to 8. These trees take up to 20 years to reach their full height.
The first Westerner to bring this tree to the attention of the world was none other than the legendary plant explorer Ernest Henry Wilson. In 1901, Wilson collected seeds of Acer griseum during one of his expeditions to China for the Veitch Nurseries in England. These seeds were then used to propagate the first Paperbark Maples in the West.
The first Paperbark Maple to be planted in North America arrived at the Arnold Arboretum in 1907, where it was grown from seeds collected by Wilson on his second expedition to China. This tree, along with another specimen planted at the same time, still stands at the Arboretum today.
Despite its popularity, the Paperbark Maple remains relatively rare in the wild. In recent years, conservation efforts have been underway to protect this species and ensure its survival for future generations. These efforts include the establishment of seed banks and the collection of wild specimens for cultivation in botanical gardens and arboreta around the world.
Identifying Physical Characteristics
- Growth habit: The Paperbark Maple has an upright oval habit.
- Size: It is a relatively small, growing to a height of 20 to 30 feet and a width of 15 to 25 feet.
- Bark: The bark peels away in thin, translucent sheets, revealing a smooth, cinnamon-red inner bark underneath. It may become fissured in old trees.
- Leaves: The tree has trifoliate leaves (each leaf has three leaflets). The leaflets are dark green in summer with silvery-gray undersides, and they turn brilliant shades of red, orange, and pink in fall.
- Shoots: The shoots are densely downy at first, this wearing off by the second or third year and the bark exfoliating by the third or fourth year.
- Flowers and Fruits: The Paperbark Maple produces small, inconspicuous greenish-yellow flowers in spring. The flowers are followed by winged fruits (samaras) that resemble maple helicopters. However, unlike other maples, most of the seeds produced by the Paperbark Maple are sterile.
Habitat and Growing Conditions
- The tree thrives in temperate climates, with its hardiness ranging from USDA zones 4 to 8.
- It’s adaptable to a variety of soil types, including sand, loam, or clay, and tolerates a wide range of pH levels. It’s also considered deer-resistant.
- The tree can grow well in full sun to partial shade.
- It grows slowly, taking up to 20 years to reach its full height.
- It is relatively disease-resistant but can be affected by pests like aphids and scale insects.
Interesting Facts about Paperbark Maple
- In its native range, it is found at altitudes of 1,500–2,000 m (4,921–6,562 ft).
- It was introduced to cultivation in Europe in 1901 by Ernest Henry Wilson for the Veitch Nurseries in the UK, and to North America shortly after.
- While a popular ornamental tree, the Paperbark Maple is actually listed as endangered in its native China due to habitat loss.
- Paperbark Maples are notoriously difficult to propagate from cuttings or seeds.
- The papery bark peeling is more than just for looks! The continuous exfoliation is thought to help the tree deter insects and other pests that might try to burrow underneath.
- It is one of the last maples to show off its fall colors. While other maples are ablaze with red and orange, the Paperbark Maple waits until late fall before its leaves turn vibrant shades of red, orange, and even pink.
- It produces winged seeds (samaras) that look like classic maple “helicopters.” However, unlike many other maples, most of these seeds are sterile and won’t germinate.
- The tree thrives in temperate climates, with its hardiness ranging from USDA zones 4 to 8.
- This plant has gained the Royal Horticultural Society’s Award of Garden Merit.