morphological character
Annual or biennial herbs, 20~40 cm high, the whole plant (except fruit) is smooth and hairless. Petiole length 1~2 cm or subsessile, sheath narrowly lanceolate; The leaves are pinnately divided twice, and the last lobe is narrowly linear, with a length of 1.5 ~ 5cm and a width of 0.3 ~ 0.5 mm. ..
There are many compound umbels, most of which are bifurcated branches, and the diameter of umbels is 2 ~ 3cm;; The involucral bracts are 3-6, linear or linear-lanceolate, with membranous edges, white, awn-like spines at the top, sometimes 3-parted, unequal in length, 1~5 cm long, and reflexed; There are 3~5 umbrella spokes with different lengths.