Rheum rhaponticum: mystery plant in our garden

(Question)

About four years ago we discovered a rather strange- looking plant in our garden. It is in a corner where there is mostly shade. It grew larger over the years
and as you can see from photo it has produced some blossoms or seeds. Can you identify it.?

With thanks,

IMG_2221

(Answer)

This looks like Rheum rhaponticum, commonly known as ‘False Rhubarb’ although, in fact, it is a true member of the rhubarb family. It is not native to Canada, but found throughout South East Asia, Siberia and into Europe.

This species is larval food for many species of butterflies. It is also used medicinally and as a food source when cooked. It is important to note that the leaves and stems contain substances toxic to humans (oxalic acid and glycosides). For more information: https://www.pfaf.org/user/Plant.aspx?LatinName=Rheum+rhaponticum