Bur-reed (Sparganium) are a plant genus of the bulrush family and occur in about 21 different species. They grow on damp to wet, temporarily or always flooded sites on water banks, swamps and bogs. Due to their (under suitable conditions) very dense stands, they form so-called reed beds.They often occur together with cattails, sedges and rush species.
Bur-reed species are green overwintering perennial herbaceous plants, some of which grow completely underwater or with floating leaves and inflorescences at or above the water surface. The alternate deciduous leaves are oblong, grass-like in shape, and consist of a spongy floating tissue. The inflorescence consists of male and female spherical partial inflorescences that grow as white to dark green, spiny-looking flower heads.
"Sparganium erectum. Forest Farm Pond. 1990" by Dr Mary Gillham Archive Project is licensed under CC BY 2.0
"Sparganium fluctuans (floating bur-reed), Abbey Pond, Ripton, VT" by Doug McGrady is licensed under CC BY 2.0