[1][4] Zuloaga, F. O., O. Morrone, M. J. Belgrano, C. Marticorena & E. Marchesi.

Catálogo de las plantas vasculares del Cono Sur.

Monographs in systematic botany from the Missouri Botanical Garden 107(1–3): i–xcvi, 1–3348.

The genus name is derived from Ancient Greek speiros = spiral, stachys = spike, in allusion to the spiral arrangement of the florets on the flower spike.

Thus were created two illegitimate homonyms, unacceptable according to the rules of nomenclature.