Paul Harcourt Davies / Bistort flowers (Persicaria bistortum), Piano Grande, Sibillini, Umbria, Italy. June 2016

Paul Harcourt Davies / Bistort (Persicaria bistortum) flower with hoverfly, Piano Grande, Sibillini, Umbria. June.

Nick Upton / Meadow bistort (Bistorta officinalis / Polygomum bistorta) flowering in profusion on Piva plateau, near Trsa, Montenegro, July.

Robert Thompson / Bistort (Polygonum bistorta) near Lac du Bornon, Mercantour National Park, Provence, France, June.

Radomir Jakubowski / European bistort (Bistorta officinalis) flower, Vosges Mountains, France, June.

Florian Möllers / Wetlands meadow with Common bistort (Polygonum bistorta) in a nature reserve in Berlin, Germany.

Rob Tilley / Wild flower meadow with Lupin, Paintbrush and Bistort, Paradise Mt. Rainier NP, Washington, USA, August 2010

Andy Sands / Red Clover (Trifolium pratense) and Common Bistort (Persicaria / Polygonum bistorta) growing with Buttercups in hay meadow, Upper Teesdale, Co. Durham, UK, June

Andy Sands / Common Bistort (Bistorta officinalis) growing with Buttercups (Ranunculus) in Hay meadow, Upper Teesdale, Co. Durham, UK, June

Kirkendall-Spring / Mount Rainier and wildlflower meadow in Edith Creek Basin of Mount Rainier National Park, Washington, USA

WILLIAM OSBORN / Bistort {Polygonum bistorta} flowering in meadow, Glos, UK

Rolf Nussbaumer / Wildflowers in alpine meadow - Heartleaf Arnica {Arnica cordifolia}, Indian Paintbrush {Castilleja sp} and Bistort {Persicaria sp}, Ouray, San Juan Mountains, Rocky Mountains, Colorado, USA, July 2007