Strobilanthes flexicaulis is a species of flowering plant in the family Acanthaceae, native to the Ryukyus and Taiwan. A much-branched subshrub reaching , it is found at elevations from , typically beside streams in forests.
The following varieties are accepted:
All Strobilanthes flexicaulis var. flexicaulis individuals simultaneously flower at six-year intervals, and then die, but S. f. var. tashiroi does not exhibit periodic mass flowering.