Ross Hoddinott / Blue-tailed damselfly (Ischnura elegans), male on Common horsetail (Equisetum arvense), Cornwall, UK. June.

Graham Eaton / Llyn Cwmorthin, with Common horsetail (Equisetum arvense) Tanygrisiau, Wales, February 2014

Graham Eaton / Common Horsetail (Equisetum arvense) growing on the Llyn Peninsular coast, near Nefyn, North Wales

Bernard Castelein / Field horsetail (Equisetum arvense) fertile shoots, Brasschaat, Belgium, April.

Kevin Schafer / Field Horsetail (Equisetum arvense) plants emerging from shallow water, Moses Coulee, Washington

Piotr Naskrecki / Field Horsetail (Equisetum arvense) releasing sporophytes, Estabrook Woods, Massachusetts

Paul Hobson / Common field Horsetails (Equisetum arvense) in spring showing cones, Yorkshire, UK, May

Paul Hobson / Common field Horsetails (Equisetum arvense) in spring showing cones, Yorkshire, UK, May

Paul Hobson / Common field Horsetails (Equisetum arvense) in spring showing cones, Yorkshire, UK, May

Nature Production / Common Field Horsetail {Equisetum arvense} with roots, flowering stalk and fronds visible, Gumma, Japan

Nature Production / Common Field Horsetail dry spores (microscopic photography) {Equisetum arvense} Japan

Nature Production / Common Field Horsetails {Equisetum arvense} Japan