Some ferns and the pennywort will grow on the wall close to the roof.
The flowers of the pennywort are greenish-white, tinged with red.
Just where I am staying now the pennywort grows on every wall attached to the mortar between the cobbles.
According to Gerarde this cymbalari was an aquatic species of pennywort, highly poisonous.
The pennywort is one of those plants with a creeping stem, which lies along the surface of the ground.