Spinulum canadense (Nessel) A. Haines

Spinulum canadense (Nessel) A. Haines is a synonym sensu Kurtto, A. & P. Uotila, 2019 of:

Spinulum annotinum subsp. dubium (Zoëga) J.H. Xue, Chepinoga & K.P. Ma, an accepted subspecies name sensu Hassler, 2014-2024+.