Rome: An Italian family of four has been left paralysed after the grandmother of the household accidentally garnished their pasta with a poisonous plant, Italian media reports.

Carmela Messina, 66, found the poisonous herb Devil's Trumpet in some bushes near a market.

Nonna planted the wrong thing: herbs and leafy greens growing in a garden. Credit:Greg Malouf

Believing it to be a bitter green broccoli variant, she took it home and planted it in her herb collection.

She sprinkled it on the family's evening spaghetti on Monday and fell ill soon afterwards along with her husband, daughter and young grandson.