The weed referred to as ‘Marestail’ is also called common horsetail (Equisetum arvense). It is an invasive and deep rooted plant that grows via fast-growing rhizomes (underground stems). Marestail is a very primitive plant that was around before the dinosaurs. It reproduces by producing spores that are airborne and travel on the wind as well as by underground stems (modified roots called rhizosomes). This means it can be a tricky ‘weed’ to control.