Rhinanthus

Rhinanthus is a genus of flowering plants in the family Orobanchaceae, commonly known as yellow rattle. The genus comprises about 40 species that are native to temperate regions of Europe, Asia, and North America. Rhinanthus species are hemiparasitic plants, meaning they photosynthesize but also extract water and minerals from other plants through haustorial connections to host roots, typically grasses and herbaceous plants.

Rhinanthus plants are usually tall, herbaceous perennials or annuals, with erect stems and simple or slightly toothed leaves. The flowers are yellow and two-lipped, often with a darker blotch on the lower lip, and arranged in spikes or racemes. After flowering, they form inflated capsules containing many small seeds; when mature, the seeds rattle inside the pods, which gives rise to the common name “yellow rattle.”

Ecology and management: As semi-parasites, Rhinanthus species influence plant community composition by weakening grasses and enabling more diverse sward mixtures. This has led to their use in biodiversity-friendly meadow creation and restoration, where they can help promote flowering plants and wildlife by reducing competitive dominance of grasses. They prefer open, nutrient-poor to moderately fertile soils and are commonly found in meadows, pastures, and light woodlands.

Taxonomy and distribution: Notable species include Rhinanthus minor (common yellow rattle) and Rhinanthus major (large yellow rattle). Other species occur across Europe and Asia, with some reaching North America. Many populations are sensitive to habitat loss and agricultural intensification, making conservation of traditional meadow habitats important for their persistence.