Viper's grass

Scorzonera humilis (viper's grass, dwarf viper's-grass) is a small, slender herbaceous perennial of the daisy family (Asteraceae), growing 7–50 cm tall from a stout, blackish, vertical taproot. The plant produces a basal rosette of mostly unbranched, elliptic-lanceolate to oblong leaves that are entire-margined and gradually taper into a winged petiole, with a few much-reduced bract-like leaves on the largely leafless flowering stem. Each stem terminates in a single solitary flower head 2.5–3 cm across composed wholly of deep yellow ligulate (strap-shaped) ray florets, the head subtended by short, pale green, glabrous involucral bracts, flowering from May to July. Broken stems and roots exude a copious milky white latex. The fruit is a smooth, ribbed, beakless achene topped with a long, pale, feather-like (plumose) pappus similar to that of Tragopogon. Native to damp meadows, fen-meadows, marshy hollows, and unimproved acid grasslands across much of central, western, and northern Europe, the species is rare in Britain where it is restricted to a few populations in Dorset, Warwickshire, and south Wales.