Quercus acutissima
Asian oak species naturalized in North America, often invasive.
Quercus acutissima, commonly known as the sawtooth oak, is a medium-sized deciduous tree native to Asia, including China, Korea, Japan, Indochina, the Himalayas, and southeastern Tibet. It is widely planted in many lands and has become naturalized in parts of North America, where it is considered a problematic invasive species in some areas.
- species
- Quercus acutissima
- common_name
- Sawtooth oak
- native_range
- China, Korea, Japan, Indochina, Himalayas, southeastern Tibet
- height
- 25–30 meters (82–98 feet)
- trunk_diameter
- Up to 1.5 meters (5 feet)
- leaf_length
- 8–20 centimeters (3.25–7.75 inches)
- acorn_maturation
- About 18 months
Lore & Background
Quercus acutissima is closely related to the Turkey oak, classified in Quercus sect. Cerris, characterized by soft bristles on shoot buds, bristle-tipped leaf lobes, and acorns maturing in about 18 months. The tree has dark gray, deeply furrowed bark and leaves with 14–20 small saw-tooth-like triangular lobes per side. Its flowers are wind-pollinated catkins, and the acorns are bicolored with an orange basal half and green-brown tip, capped with dense 'mossy' bristles.
Two subspecies are accepted: Quercus acutissima subsp. acutissima, found in Japan, Korea, Manchuria, China, Vietnam, Thailand, and Cambodia; and Quercus acutissima subsp. kingii, native to Nepal, the eastern Himalayas, Myanmar, and Laos. The acorns are very bitter but eaten by jays and pigeons; squirrels usually eat them only when other food is scarce. The sap can leak from the trunk, attracting beetles, stag beetles, butterflies, and Vespa mandarinia.
Introduced into the United States around the 1920s, sawtooth oak has become naturalized in scattered locations in eastern North America, including states such as Florida, Missouri, New York, Alabama, and Pennsylvania. It thrives in well-drained acid soils and grows faster than many native trees, allowing it to outcompete native species and become invasive in some areas, such as Louisiana.
Reader's Guide
Quercus acutissima is significant as a widely planted ornamental and wildlife food source, but its introduction has led to ecological concerns. The species was brought to North America primarily for wildlife food provision, as it tends to bear heavier acorn crops than native oaks; however, the bitterness of its acorns reduces their value for this purpose. Its fast growth and ability to thrive in harsh locations enable it to outcompete native species, potentially disrupting ecosystems. Researchers advise removing saplings and excluding the species from reclamation lists to mitigate harm.
The wood, though similar to other oaks, is prone to cracking and splitting, limiting its use to fencing. Charcoal from the wood is used for braziers in the Japanese tea ceremony. The tree's naturalization in parts of North America and its invasive potential highlight the unintended consequences of introducing non-native species. Its classification in Quercus sect. Cerris underscores its botanical relationship with the Turkey oak, and its two subspecies reflect a broad native range across Asia.
Did You Know?
- The acorns of Quercus acutissima are very bitter and are eaten by jays and pigeons; squirrels usually eat them only when other food sources have run out.
- The tree's sap can leak from the trunk, attracting beetles, stag beetles, butterflies, and Vespa mandarinia.
- Quercus acutissima was introduced into the United States around the 1920s and has become naturalized in states including Florida, Missouri, New York, Alabama, and Pennsylvania.
- Charcoal made from sawtooth oak wood is used for braziers in the Japanese tea ceremony.
More in Flowering Trees & Shrubs 1-20
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