Bernard Castelein / Alder buckthorn (Frangula alnus) tree at dawn. Klein Schietveld, Brasschaat, Belgium. April.

Bernard Castelein / Alder buckthorn (Frangula alnus) in grassland at sunrise. Klein Schietveld, Brasschaat, Belgium. August 2019.

Alex Hyde / Common buckthorn (Rhamnus cathartica) leaves and berries, Strumpshaw Fen, Norfolk, UK, September.

Kim Taylor / Brimstone butterfly (Gonepteryx rhamni) eggs on Alder Buckthorn (Frangula alnus) leaf. Surrey, England, UK, May. Digitally enhanced.

Alex Hyde / Leaves and fruits of Common buckthorn (Rhamnus cathartica) Cambridgeshire, UK. September.

Wild Wonders of Europe / Widstr / Jerusalem Thorn (Paliurus spina-christi) Sakar Mountains, Eastern Rhodope Mountains, Bulgaria, May 2013.

Simon Colmer / Purging Buckthorn berries (Rhamnus cathartica) Levin Down NR, Sussex, UK

Simon Colmer / Purging Buckthorn berries (Rhamnus cathartica) Levin Down NR, Sussex, UK

Chris O'Reilly / Alder buckthorn berries {Rhamnus frangula} Derbyshire, UK

Jose B. Ruiz / Mediterranean buckthorn berries {Rhamnus alaternus} Alicante, Spain

Jose B. Ruiz / Rhamnus lycioides berries, Spain, Europe

Jose B. Ruiz / Ladder snake (Elaphe scalaris) climbing shrub (Rhamnus lycioides) Allicante, Spain