Pen gentian is an annual herbaceous plant of the Gentianaceae family and Gentiana genus. The stem is upright, purple red, branched from the base, sparsely unbranched; Leaves oval or oval spoon shaped, margin cartilaginous, smooth or with indistinct fine papillae; Most flowers, solitary at the top of small branches, densely arranged in umbrella shaped branches, sparsely solitary at the top of flowers; The capsule is exposed or hidden, inverted oval shaped and rectangular in shape, with wide wings; The seeds are brown, oval in shape, with a fine mesh on the surface; The flowering and fruiting period is from April to June. Because its flowers resemble a pen tip when closed, it is named "Pen Dragon Gallbladder".