Rough Hawk's-beard

Crepis biennis is a biennial herb that grows to a height of 20-120 cm, with a robust taproot and a single, erect flowering stem. The first-year rosette leaves are narrowly obovate, ranging from 5.0 to 25.0 cm in length and 1.5 to 7.5 cm in width, with runcinate, pinnatisect, or dentate margins. The cauline leaves are narrowly ovate to linear, often entire or pinnatifid, and become reduced to scales at the apex. The synflorescence is corymbiform or paniculiform, bearing 12-14 flower heads. Each head contains 30-100 yellow ligulate flowers, with a cylindrical or campanulate involucre. The involucral bracts are linear-ovate, greenish, and minutely ciliate at the apex. The receptacle is flat, pitted, and ciliate, with no scales. Achenes are fusiform, 4.0-7.0 mm long, and adapted for wind dispersal.

Crepis biennis is typically found in a variety of open habitats, including meadows, roadsides, and disturbed areas. It thrives in temperate climates and is often associated with well-drained soils. The plant is native to Europe and parts of Asia Minor and has been introduced to scattered locations in the northeastern United States and Newfoundland, Canada. It is adaptable to a range of environmental conditions but prefers full sun to partial shade.

Crepis biennis is relatively easy to cultivate in gardens that mimic its native habitat. It prefers well-drained soils and full sun to partial shade. The plant can be propagated from seed, which should be sown in early spring or fall. It is drought-tolerant once established and does not require frequent watering. The plant may self-seed in favorable conditions, making it a good choice for naturalized plantings. However, it is not typically cultivated for ornamental purposes and is more commonly observed in wild or semi-wild settings.

Crepis biennis is primarily of ecological interest, serving as a food source for various insects and contributing to the biodiversity of meadow and roadside habitats. It is not commonly used in horticulture or agriculture. Historically, some species in the genus Crepis have been used in traditional medicine, but there is no specific record of medicinal use for C. biennis. The plant is also of taxonomic interest due to its role in the classification and nomenclature of the genus Crepis.