Juan Manuel Borrero / Carvao aqueduct with Chilean rhubarb (Gunnera tinctoria) at base. Devasa mountain range, Sao Miguel Island, Azores, Portugal. 2019.

Juan Manuel Borrero / Chilean gunnera (Gunnera tinctoria) at edge of footpath, woman hiking along path. Devasa mountain range, Sao Miguel Island, Azores, Portugal. 2019.

Adrian Davies / Chilean rhubarb (Gunnera manicata) leaf in autumn showing remnant of green.

Doug Wechsler / Gunnera (Gunnera sp) leaf bud, Yanacocha Reserve, Ecuador.

Doug Wechsler / Gunnera (Gunnera sp) leaf bud, Yanacocha Reserve, Ecuador.

Doug Wechsler / Gunnera leaves (Gunnera sp) Yanacocha Reserve, Ecuador

Doug Wechsler / Giant leaves of Gunnera sp in cloud forest, Province Zamora-Chinchipe, Tapichalaca Biological Reserve, Ecuador

Alex Hyde / Vegetaion including huge leaves of (Gunnera insignis) growing next to the crater rim of Volcano Irazu, 3400m Costa Rica

Alex Hyde / Poor Man's umbrella (Gunnera insignis) growing around the caldera rim of Volcano Irazu, Costa Rica

Adrian Davies / Chilean rhubarb leaf (Gunnera manicata) dead in winter, showing pattern of veins.

Angelo Gandolfi / Brazilian rhubarb (Gunnera manicata), State of Santa Catarina, Brazil, September.

Angelo Gandolfi / Brazilian rhubarb (Gunnera manicata), State of Santa Catarina, Brazil, September.

Martin Gabriel / Poorman`s Umbrella (Gunnera insignis) growing at an altitude of 3200m on Irazu volcano, Costa Rica, February

Konrad Wothe / Gunnera (Gunnera insignis) in mountain rainforest of Tapanti National Park, Costa Rica

Martin Gabriel / Poor man's parasol (Gunnera insignis) in flower near Mirador de Quetzales, Costa Rica

Luiz Claudio Marigo / Giant Rhubarb (Gunnera manicata) on the slope of the road to Aparados da Serra National Park, Santa Catarina State, Southern Brazil.

Luiz Claudio Marigo / Giant Rhubarb (Gunnera manicata) on the slope of the road to Aparados da Serra National Park, Santa Catarina State, Southern Brazil.

Adrian Davies / {Gunnera tinctoria} attempt by farmer to kill with weedkiller, the glyphosate RoundUp, County Mayo, Ireland, May.

Adrian Davies / Parrot feather (Myriophyllum aquaticum) cleared from village pond, Prawle, Devon, England. Note large area of the invasive weed still left behind in the pond.

Adrian Davies / Parrot feather (Myriophyllum aquaticum) cleared from village pond, Prawle, Devon, England. Note large area of the invasive weed still left behind in the pond.

Adrian Davies / Parrot feather (Myriophyllum aquaticum) cleared from village pond, Prawle, Devon, England. Note large area of the invasive weed still left behind in the pond.

Adrian Davies / Parrot feather (Myriophyllum aquaticum) cleared from village pond, Prawle, Devon, England. Note large area of the invasive weed still left behind in the pond.

Adrian Davies / Gunnera tinctoria - invasive plant species growing on large tracts on land on Achill Island, County Mayo, Ireland

Adrian Davies / Gunnera tinctoria - invasive species growing around Carrick Kildavnet Castle, Achill Island, County Mayo, Ireland.

Adrian Davies / Gunnera tinctoria - invasive plant species growing on large tracts on land on Achill Island, County Mayo, Ireland

Adrian Davies / Gunnera tinctoria - invasive plant species growing on large tracts of land on Achill Island, County Mayo, Ireland

Adrian Davies / Gunnera tinctoria - invasive plant species growing on large tracts of land on Achill Island, County Mayo, Ireland

Willem Kolvoort / View to surface with Spiked watermilfoil (Myriophyllum spicatum) in sand winning pit, South Holland

Willem Kolvoort / Underwater view of Spikes water milfoil (Myriophyllum spicatum) Lake Naarden, Holland

Philippe Clement / Man sticking head through Poor man's umbrella (Gunnera insignis) in cloud forest, Tapanti NP, Costa Rica

Philippe Clement / Poor man's umbrella (Gunnera sp) in cloud forest, Tapanti NP, Costa Rica

Philippe Clement / Poor man's umbrella (Gunnera sp) in cloud Forest, Tapanti NP, Costa Rica

Philippe Clement / Cloud forest vegetation with Poor Man's Umbrella (Gunnera sp) in foreground, Tapanti NP, Costa Rica

Adrian Davies / Parrot's feather {Myriophyllum sp} a highly invasive, non native plant, choking a village pond in Devon, UK

Adrian Davies / Parrot's feather {Myriophyllum sp} a highly invasive, non native plant, choking a village pond in Devon, UK

Adrian Davies / Parrot's feather {Myriophyllum sp} a highly invasive, non native plant, choking a village pond in Devon, UK

Pete Oxford / Poor Man's Umbrella {Gunnera sp} Cloud Forest, Ecuador

Philippe Clement / Close-up of Mare's tail {Hippuris vulgaris} Belgium.

Duncan Mcewan / Mare's tail {Hippuris vulgaris} Scotland Perthshire

Kevin Schafer / Poor Man's Umbrella (Gunnera insignis) leaves showing ribs and veination, Volcan Irazu National Park, Costa Rica

Dr. Axel Gebauer / Mare's tail (Hippuris vulgaris) on marsh meadow, Koko Nor lake, Tso Ngonbo, Qinghai Hu, Qinghai Province, Tibet

Dr. Axel Gebauer / Mare's tail (Hippuris vulgaris) on marsh meadow, Koko Nor lake, Tso Ngonbo, Qinghai Hu, Qinghai Province, Tibet

Dr. Axel Gebauer / Mare's tail (Hippuris vulgaris) growing in marsh meadow, Koko Nor lake, Tso Ngonbo, Qinghai Hu, Qinghai Province, Tibet