Big caltrop
Kallstroemia maxima
Prostrate herb with ascending stem tips; leaves opposite, once-pinnately compound, even-pinnate; leaflet shape variable in detail, but generally oblong-elliptic with acute apices and asymmetric bases, especially so on the terminal leaflets; flowers axillary; petals yellow or pale orange; fruits spiny.
The word "caltrop" is a fine, old one, going back at least a thousand years. One kind of caltrop is an iron ball equipped with four spikes disposed so that when the ball lies on the ground one of the spikes always points upward. Caltrops are strewn before advancing cavalry, armored vehicles and the like. The word caltrop derives from the Old English Calcatrippe, based on the Latin "calci," referring to a spur or heel, and "trœppe," which became "trap." It's a trap for the heel.
The word "caltrop" is a fine, old one, going back at least a thousand years. One kind of caltrop is an iron ball equipped with four spikes disposed so that when the ball lies on the ground one of the spikes always points upward. Caltrops are strewn before advancing cavalry, armored vehicles and the like. The word caltrop derives from the Old English Calcatrippe, based on the Latin "calci," referring to a spur or heel, and "trœppe," which became "trap." It's a trap for the heel.