Equisetum arvense AG.JPG
Perennial, 10-50 cm high. Stems articulated, with hollow internodes. Spring stems (March-May) brownish, not branched, with a blunt apical sporebearing spikelet. Summer stems barren, soft, with numerous branch whorls. Along rivers and streams, wet places. From plains to the middle mountain belt. Temperate zone of the world.