Cyril Ruoso / Woman with baby collecting Madagascar periwinkle (Catharanthus roseus) flowers and leaves, used in herbal medicine, and containing molecules which are used in the treatment of leukemia cancer. Berenty...

Enrique Lopez-Tapia / Spiny tree trunk (Pachypodium sp) Berenty Reserve, Madagascar.

Nick Garbutt / Giant Pachypodium species photographed from the inside. Lake Tsimanampetsotsa National Park, South West Madagascar.

Richard Du Toit / Impala lily flower (Adenium multiflorum) Sabi Sand GR, South Africa, October

Jouan & Rius / Elephant's foot plant (Pachypodium lameri) in flower, Isalo NP, Madagascar

Pete Oxford / Elephant's foot plant (Pachypodium horombensis) Isalo National Park, MADAGASCAR, endemic

Nick Upton / Shrubby milkweed (Gomphocarpus fruticosus), invasive species native to South Africa. Beside Rio Codula di Luna stream, Gennargentu National Park, Dorgali, Sardinia. June.

Derek Galon / Caterpillar of Monarch butterfly (Danaus plexippus) feeding on seed pod of Bloodflower plant ( Asclepias curassavica). Dominica, Eastern Caribbean, Lesser Antilles. Focus stacked photo.

Derek Galon / Seeds of Bloodflower plant (Asclepias curassavica) blown by wind from their pod. Dominica, Eastern Caribbean, Lesser Antilles. Focus stacked photo.

Joao Burini / Milkweed (Asclepias mellodora), Intervales State Park, Sao Paulo, Atlantic Forest South-East Reserves, UNESCO World Heritage Site, Brazil.

David Fleetham / View up through the blossom of a Frangipani tree (Plumeria sp) Maui, Hawaii.

Sylvain Cordier / Rose of Desert (Adenium obesum ssp Sokotran) Socotra Island, UNESCO World Heritage Site, Yemen.