Bamboo is commonly associated with the landscapes and cultures of Asia. This widespread perception has led to the belief that the plant, a member of the grass family Poaceae, is an exclusively imported species in North America. However, this is a misconception, as a true bamboo genus is native to the continent. The native species exhibit distinct characteristics that separate them from the more familiar ornamental varieties often seen in landscaping.
The Native North American Genus
The only bamboo genus indigenous to North America is Arundinaria, often referred to by the common names of cane, river cane, giant cane, or switch cane. The genus has a complex taxonomic history, but it is currently recognized to contain three to four distinct species. All of these species are native to the southeastern portion of the continent, where the climate supports their perennial growth habit.
- Arundinaria gigantea (Giant Cane or River Cane)
- Arundinaria tecta (Switch Cane)
- Arundinaria appalachiana (Hill Cane)
- Arundinaria alabamensis (Tallapoosa Cane)
Physical Characteristics and Range
The native Arundinaria species are characterized by their slender, woody stems, known as culms, and their running growth habit. They spread aggressively through leptomorph rhizomes, which are underground stems that extend horizontally, allowing the plant to form dense colonies. These culms can reach heights ranging from 1.6 feet up to 26 feet, depending on the species and growing conditions.
The leaves are lance-shaped and narrow. Some species, like A. appalachiana, drop their leaves in the fall. The historic range of Arundinaria extended across the southeastern United States, reaching from Maryland and the Ohio Valley down to Florida and west into Texas. They thrive in moist, fertile soils, often found in bottomlands, floodplains, and along riverbanks.
The largest species, Arundinaria gigantea, can tolerate temperatures as low as -20 degrees Fahrenheit, demonstrating its adaptation to temperate climates. The stems are typically hollow between the nodes and are characterized by persistent leaf sheaths that have stiff, rough bristles.
Ecological Role and Conservation Status
The dense, single-species stands formed by native bamboo are called canebrakes, which historically covered hundreds of thousands of hectares across the Southeast. These canebrakes function as a unique ecosystem, providing a habitat for specialized wildlife, including insects, birds, and mammals. Several species of skipper butterflies, for example, use river cane as their host plant, earning them the designation of “canebrake specialists.”
Canebrakes play a significant role in maintaining ecosystem health, especially in riparian zones. Their extensive rhizome network stabilizes stream banks and helps control soil erosion. The thick growth also acts as a natural buffer, filtering excess nutrients and sediments from agricultural runoff, which enhances local water quality.
Canebrakes are now considered an endangered ecosystem. Since European settlement, these habitats have been reduced to less than 2% of their original extent, primarily due to clearing for agriculture and logging. Practices like fire suppression and overgrazing by livestock also contributed to the decline, as the plant is adapted to periodic fire disturbance. Restoration efforts are challenging because the plant reproduces infrequently by seed, relying mostly on slow-growing vegetative spread.
Distinguishing Native from Imported Species
Distinguishing native Arundinaria from non-native ornamental bamboos (such as those in the Phyllostachys or Bambusa genera) requires attention to specific botanical details. A practical distinction is culm size: native river cane stems are typically less than one inch in diameter. In contrast, many imported bamboo species frequently have stems greater than one inch, often reaching diameters of several inches in large varieties.
The branching pattern that emerges from the nodes is also different. On Arundinaria culms, the branches tend to be tangled and grow almost parallel to the main stem, pointing upward. Non-native species often have branches that emerge from the node at a more outward angle, typically around 45 degrees.
The stems of many non-native running bamboos, like Golden Bamboo (Phyllostachys aurea), possess a distinguishing feature called a sulcus, which is a noticeable groove running down the length of the internode. Native Arundinaria culms, however, are perfectly round and lack this prominent groove.