Nigel Cattlin / Branched bur-reed (Sparganium erectum) on canal bank. Berkshire, England, UK. June.

Nick Hawkins / Red trillium (Trillium erectum), photographed on white background, New Brunswick, Canada, May.

Adrian Davies / Branched bur reed (Sparganium erectum) Surrey, UK, August.

Bernard Castelein / Simplestem bur-reed (Sparganium erectum), Peerdsbos, Brasschaat, Belgium, July.

Nick Upton / Branched bur-reed (Sparganium erectum) flowering in a small stream with white female flowers with protruding white styles and the spiky burs they develop into below, and rounder male flowers on branch...

Nick Upton / Branched bur-reed (Sparganium erectum) flowering in a small stream with white female flowers with protruding white styles and the spiky burs they develop into below, and rounder male flowers on branch...

Doug Wechsler / Red Trillum (Trillium erectum) Fairmount Park, Wissahickon Creek, Philadelphia, Pennsylvania, USA, May.

Loic Poidevin / Purple trillium (Trillium erectum) Jacques Cartier Park, Quebec, Canada, May

Loic Poidevin / Purple trillium (Trillium erectum) Jacques Cartier Park, Quebec, Canada, May

Adrian Davies / Branched bur-reed (Sparganium erectum) flowering, County Meath, Republic of Ireland, July

Colin Varndell / Branched Bur-Reed (Sparganium). Little Sea, Studland, Dorset, June.

Jerry Monkman / Red Trillium {Trillium erectum} flower, Mt. Passaconoway, New Hampshire, USA

Dave Watts / Branched bur reed {Sparganium erectum} UK

Jaymi Heimbuch / Purple Trillium (Trillium erectum) flowering, Butano State Park, California

Will Watson / Black colonel (Odontomyia tigrina), a soldier fly, on Branched bur-reed (Sparganium erectum) pond, Herefordshire, England, UK. June.

Will Watson / Beautiful china-mark (Nymphula nitidulata) on Branched bur-reed (Sparganium erectum), pond, Herefordshire, England, UK. June.

Will Watson / Beautiful china-mark moth (Nymphula nitidulata) on Branched bur-reed (Sparganium erectum), Herefordshire, England, UK. June.

Nick Upton / Reed beetle (Donacia marginata) standing on a leaf of its host plant, Branched Bur-reed (Sparganium erectum) on the margins of a stream, Wiltshire, UK, May.

Linda Pitkin / Branched Bur-reed (Sparganium erectum) watercolour illustration

Linda Pitkin / Branched bur-reed (Sparganium erectum) in pond, South West London, England, UK. June.

Linda Pitkin / Branched bur-reed (Sparganium erectum), South West London, England, UK. June.

Linda Pitkin / Branched bur-reed (Sparganium erectum) Langham Ponds SSSI), Runnymede (NT), Surrey, England, July.

Will Watson / Margined reed beetle (Donacia marginata) on Branched bur-reed (Sparganium erectum), Shatsky National Natural Park, Volyn Oblast, Ukraine, May.

Nigel Cattlin / Branched bur-reed (Sparganium erectum) male above and female flowers below on lateral branched stems, canal bank, Berkshire, England, UK, June