Equisetum fluviatile Equisetum fluviatile L., Sp. E. limosum L., Sp. E. maximum Lam., Fl. Internally there is only carinal collenchyma, chlorenchyma is continuous under the valleys, and interrupted under the collenchyma. Endodermis individual around each vascular bundle.
Larger branches resemble small stems.
Valleys rounded, with stomata scattered across the valley or tending to be in bands on either side. Silica pilules scattered over surface of stomate, outlining it and lining the stoma. Mamillae transversely aligned, distinct. Rhizome smooth, light brown, glabrous, with black roots. Gametophytes with plates often becoming filamentous at tips, sparse or absent on the male.