The roots of D. velutina were collected from Sahatsakhan district,
Kalasin province, Thailand, in October 2014. The plant material was
identified by Ms. Suttira Khumkratok, a botanist at the Walai Rukhavej
Botanical Research Institute, Mahasarakham University, and a specimen
retained as a reference (Khumkratok no. 4–12).