Position in a system
| system | Vitae - living organisms |
| domain | Eukaryota Whittaker & Margulis, 1978 - lifeforms with nucletic cells |
| superregnum | Bikonta - bikonts |
| Corticata | |
| Archaeplastida | |
| kingdom | Plantae Haeckel - plants |
| divisio | Monilophyta Cantino et Donoghue - ferns and horsetails |
| class | Equisetopsida C. Agardh |
| order | Equisetales DC. ex Bercht. & J.Presl |
| family | Calamitaceae Unger † |
| genus | Palaeostachya C.E.Weiss † |
| species | Palaeostachya dircei Gastaldo † |