## 2 Materials and Methods
### External Morphology  
Measurements and optical observations of 20 seeds for each of the 15 collection sites (voucher) for a total of 300 seeds were recorded. A digital Vernier caliper (CD-15 CP, Mitutoyo, Kawasaki, Japan) was used to measure the length, width, and length/width ratio. The general shape (\(\times\)2 magnification), cross-sectional shape (\(\times\)8 magnification), and color were recorded using a stereomicroscope (Olympus SZX16, Olympus, Tokyo, Japan) (Table 2). Cross-sections of seeds were prepared by cutting them down the middle part using a single-edge blade (DN-52, Dorco, Seoul, Korea). The hilum part was placed at the bottom, and images were captured while using a digital camera (Olympus DP21, Olympus, Tokyo, Japan). The weight of 1000 randomly selected seeds (1000-seed weight) was measured (in six replicates) using an electronic precision balance (PS 1000.R1, RADWAG Balances & Scales, Radom, Poland).  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Scientific Name** & **Collection Site** & **Collection Date** & **Voucher No.** \\ \hline Descurinia sophia ([PERSON]) [PERSON] * & \begin{tabular}{c} Pyeongtaek, Gyeonggi, Korea \\ Muju, Jeonbuk, Korea \\ Gurye, Jeonnam, Korea \\ Danyang, Chungbuk, Korea \\ \end{tabular} & 11 May 2016 & MBC_KIOM-2016-072 \\ \hline _Lepidium apetalum_ Wild. * & Antu, Yanbian, Jilin, China & 30 June 2016 & MBC_KIOM-2016-088 \\ \hline Draba memorosa L. \({}^{\dagger}\) & \begin{tabular}{c} Anseong, Gyeonggi, Korea \\ Hapcheon, Gyeongnam, Korea \\ Yuseong, Daejeon, Korea \\ \end{tabular} & 12 May 2017 & MBC_KIOM-2016-057 \\ \hline _Eysimum cheiranthoides_ L. \({}^{\dagger}\) & \begin{tabular}{c} Danyang, Chungbuk, Korea \\ Danyang, Chungbuk, Korea \\ \end{tabular} & 15 July 2016 & KIOM201601017294 \\ \hline _Eysimum cheiranthoides_ L. \({}^{\dagger}\) & \begin{tabular}{c} Danyang, Chungbuk, Korea \\ Danyang, Chungbuk, Korea \\ \end{tabular} & 28 July 2016 & MBC_KIOM-2016-228 \\ \hline _Eysimum machellentum_ Bunge * & \begin{tabular}{c} Gurye, Jeonnam, Korea \\ Andong, Gyeongbuk, Korea \\ \end{tabular} & 10 May 2016 & MBC_KIOM-2016-040 \\ \hline _Lepidium virginicum_ L. \({}^{\dagger}\) & \
\begin{tabular}{c} Sancheong, Gyeonggi, Korea \\ Buan, Jeonbuk, Korea \\ Anseong, Gyeonggi, Korea \\ \end{tabular} &
\begin{tabular}{c} 6 May 2016 \\ June 2016 \\ 12 May 2016 \\ 12 May 2016 \\ 12 May 2016 \\ \end{tabular} & MBC_KIOM-2016-075 \\ \hline \hline \end{tabular}  
* Official plant species designated as sources of Lepidiu seu Descuriniaiae Semen in the current Korean Herbal Pharmacopoeia and Pharmacopoeia of the People’s Republic of China. \({}^{\dagger}\) These plant species do not have an appropriate herbal name in the current Korean Herbal Pharmacopoeia and Pharmacopoeia of the People’s Republic of China.  
\end{table}
Table 1: List of plant species used in this study along with the collection site, collection date, and voucher number.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  
* WA, wing-like appendage. \({}^{\mathrm{b}}\) Br, brown; PBr, pale brown; RBr, reddish brown; D, dull; S, shiny. \({}^{\mathrm{c}}\) MR, mucilage reaction; \(\succ\), no reaction; \(+\), weak reaction; \(++\), moderate reaction.  
\end{table}
Table 2: Morphological characteristics of _Descurinia sophia_ and _Lepidium apetalum_ (authentic sources of Lepidiu seu Descuriniaiae Semen) and adulterant species.