Ecoregion-based conservation allows us to identify and help the world s threatened forests, rivers, prairies, wetlands and other natural communities. To learn more about our conservation efforts in one of these communities, please select a Science and Stewardship site below. Most commonly it is two or three feet high, but can grow to six feet in height. On the stems, there is a single spine below each rosette of wedge-shaped, untoothed leaves. Leaves are simple, opposite and oval to oblong in shape.
Individual flowers have five to seven petals, and are attached close to the stem.
This shade-tolerant annual is a native of Asia, but has recently spread into New York and Connecticut. It has hollow stems similar to bamboo, with swollen joints along the stem. Leaves are broadly egg-shaped, with pointed tips and squarish bases. It has alternate, glossy leaves that are oval or elliptical. They are smooth or slightly hairy, thin and from one to three inches long.