A caltrop is an area denial weapon made up of usually four, but possibly more, sharp nails or spines arranged in such a manner that one of them always points upward from a stable base. Historically, c
Roman caltrop at the Westphalian Museum of Archeology (German: Westfälisches Museum für Archäologie), Herne, North Rhine-Westphalia, Germany
Bronze caltrops from the Three Kingdoms era
A 16th-century caltrop
Traditional caltrops and mines from the Mongol Empire
Trapa natans, the water caltrop, is a widespread species of flowering plant in the genus Trapa, family Lythraceae, grown as a food crop. Other vernacular names include buffalo nut, bat nut, devil pod,
Caltrop
…also were used in the defence of samurai fortifications. Iron makibishi were called tetsubishi, while the makibishi made from the dried seed pod of the water caltrop, or water chestnut (genus Trapa), formed a natural type of makibashi called tennenbishi. Both types of makibishi could penetrate the thin soles of…