Albert Lleal / Blue Hound's Tongue (Cynoglossum creticum) noxious pasture weed seed with hooks to enable dispersal

Terry Whittaker / 2020VISION / Common sea lavender (Limonium vulgare) and Sea purslane (Halimione portulacoides) growing on regenerated saltmarsh habitat, with rainbow, Abbotts Hall Farm Nature Reserve, Essex, England, UK, July 201...

Nick Upton / Sea Purslane / Shoreline purslane (Sesuvium portulacastrum) flowering on the sandy shore of a coastal lagoon, Sotavento, Fuerteventura, Canary Islands, May.

Frederique Olivier / Thorny dragon (Moloch horridus )with Calandrinia flowers in desert habitat, Australia.

Frederique Olivier / Thorny dragon (Moloch horridus) in desert habitat, Australia.

Chris Mattison / Spring beauty (Montia perfoliata), Ainsdale Nature Reserve, Merseyside, UK, April.

RHONDA KLEVANSKY / Succulent (Avonia papyracea) growing amongst stones, Richtersveld National Park and World Heritage Site, Northern Cape, South Africa, August.

Michael Durham / Opuntia (Opuntia echios) cacti surrounded by Sea-purslane (Sesuvium edmonstonei), South Plaza Island, Galapagos Islands, Ecuador

Michael Durham / Opuntia (Opuntia echios) cactus surrounded by Sea-purslane (Sesuvium edmonstonei), South Plaza Island, Galapagos Islands, Ecuador

Wild Wonders of Europe / Möllers / Invasive species African curly weed (Lagarosiphon major) and Largeflower primrose-willow (Ludwigia grandiflora) seedlings in the Etang des Boires, Pont-du-Chateau, Auvergne, France, August 2010

Tui De Roy / Blue-footed Booby (Sula nebouxii) nesting colony among Carpetweed (Sesuvium sp) plants along shoreline, Galapagos Islands, Ecuador

Tim Laman / Bitterroot flower (Lewisia cotyledon) at Tom Martin Peak. Klamath Mountain, California.

Philippe Clement / Sea purslane (Halimione portulacoides / Atriplex portulacoides) along the Belgian coast, Belgium