Calamites cistiiformes Jointed-stemmed calamitids were an important component of Carboniferous swampland floras. The generic name Calamites was first given to the ridged and furrowed casts of the pith cavity, which are commonly encountered fossils (see FORM GENERA). Unlike their smaller modern counterparts (Equisetum species) some Carboniferous species grew to 18 m tall. Calamites cistiiformes was the first representative of the family Calamitaceae. It was first described by Stur in 1877. See also SPHENOPSIDA.

Calamites cistiiformes (horse-tails; family Calamitaceae) A species of jointed-stemmed plants that were an important component of Carboniferous swampland floras. Unlike their small modern counterparts some Carboniferous species grew to 18 m tall. Calamites cistiiformes was the earliest representative of the Calamitaceae and was first described in 1877. Calamatids are known throughout the northern hemisphere.