Giant buttercup
Ranunculus cortusifolius
Family · Ranunculaceae · Poisonous
Read this before the sheet
This plant, or one that resembles it, is dangerous. Identifying is not authorising: no app has the authority to tell you that you may eat or touch a plant.
The largest buttercup in the Portuguese flora, with leaves the size of a plate and yellow flowers four centimetres across. It grows in damp shady places on the islands and looks like nothing on the mainland.
Uplands · Oak woods · Streams and ditches
Also known asAzorean buttercup
How to tell it
A sturdy plant to a metre and a half. Enormous basal leaves, nearly round, kidney or heart-shaped, coarsely toothed at the edge on a very long fleshy stalk. Bright varnished yellow flowers three to five centimetres, in groups at the top. Range: the Azores, Madeira and the Canaries.
What it is confused with
No dangerous lookalikes known in the Iberian Peninsula.
What it is for
None. Like all buttercup relatives it contains protoanemonin: the fresh sap irritates skin and raises blisters, and swallowed it inflames mouth and gut. The size of the leaves makes it tempting to anyone looking for a wild green, which is why it needs saying.