菱 - diamond (shape), water chestnut, rhombus

rhombus-shaped mochi

caltrop

caltrop (spiked device scattered to maim infantry and horses); calthrop; caltrap

caltrop (Tribulus terrestris); cat's head; devil's thorn; devil's weed; goathead; land caltrop; puncturevine

Trapa incisa (species of plant closely related to the water caltrop)

water caltrop (Trapa natans); water chestnut; caltrop

Takebishi Electric Sales Corporation

Ryoyo Electro Corporation

flower-shaped family crest

California poppy (Eschscholzia californica); golden poppy

rhombencephalon; hindbrain

water caltrop (esp. Trapa japonica); water chestnut