A tall, coarse plant (Inula helenium) native to central Asia, having rayed yellow flower heads. The roots are used medicinally.

土木香大型粗糙的植物(土木香旋覆花属)，原产于中亚，花黄色，头状花序呈辐射状向四周延伸，根入药。

youdao

Objective: to study the chemical constituents of the essential oil of Inula helenium L. were extracted by steam distillation (SD) and supercritical-CO2 fluid (SFE).

目的：研究土木香挥发油的化学成分，并比较水蒸气蒸馏提取(SD)与超临界CO2萃取(SFE)所得土木香挥发性成分的差异。

youdao

Early forms of teeth whitening include using the herb elecampane (Inula helenium) to scrub the teeth and taking sage leaves and making a powder of them and salt.

BBC: Medieval teeth 'better than Baldrick's'