Orinus is an alpine endemic genus of Poaceae. Because of the imperfect specimens, high level of intraspecific morphological variability, and homoplasies of morphological characters, it is relatively difficult to delimitate species of Orinus by using morphology alone. To this end, the DNA barcoding has shown great potential in identifying species.
Brassicaceae is a large plant family of special interest; it includes many economically important crops, herbs, and ornamentals, as well as model organisms. The taxonomy of the Brassicaceae has long been controversial because of the poorly delimited generic boundaries and artificially circumscribed tribes.
Plants have been used throughout human history for food and medicine. However, many plants are toxic, and cannot easily be morphologically distinguished from non-toxic plants. DNA identification solves this problem and is widely used. Nonetheless, plant DNA barcode identification faces a number of challenges, and many studies have been conducted to find suitable barcodes.