Tittmannia stachydifolia Turcz. Bull. Soc. Nat. Mosc. 7: 156. 1837.
Vandellia stachydifolia Walp. Repert. 3: 294. 1884.
Mazus villosus Hemsl. Jour. Bot. 14: 209. 1876. This species, originally based on "Habitat Ta-hoo Lake, Forbes; Kiukang, Shearer; ad sinum Ta-lien-hwan, fib. Hance,",was reduced by Hemsley himself in Jour. Linn. Soc. Bot. 26: 183 (1890).
Mazus simada Masamune, Trans. Nat. Hist. Soc. Formos. 30: 35. 1940. For reduction see Li, Quart. Jour. Taiwan Mus. 3: 58 (1950).
Considerable variation appears in the leaves, in their size, serration, length of petioles, etc., but it is impossible to distinguish subspecific segregates with constant and uniform characters. With larger series of specimens, this may prove desirable.