Pentanema squarrosum, known as ploughman's-spikenard, is a species of plant in the family Asteraceae found in Europe, North Africa, and the Near East.[1] [2]
It is a tall, hairy plant (to 1.2 m) that grows on calcareous, low-nutrient, well-drained soils. It is a short lived perennial plant. Before flowering, the basal rosette of leaves resembles those of foxgloves. It flowers after mid-summer in Europe, from July to September. When in flower, the plant has many small flowerheads grouped together into a flat-topped structure that resembles a single flowerhead (pseudanthium). The individual flowerheads have prominent yellow disc florets and no (or inconspicuous) ray florets.[3]
The leaves are burned and used as an insecticide and parasiticide, especially against fleas. Even the smell of the plant is flea repellent. When the root is burned, it becomes a useful room scent (Used this way in Turkey).[4]