''Scleranthus perennis'', the perennial knawel, is a perennial

herbaceous Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of t ...

plant in the family Caryophyllaceae. It grows on sandy, dry, acidic soils. It can grow up to 15 cm high and has white flowers of 2–5 mm. The plant used to be economically significant as the major host plant of the Polish cochineal. Scleranthus perennis cropped

References

Caryophyllaceae Plants described in 1753 Taxa named by Carl Linnaeus {{Caryophyllaceae-stub