noun tropical annual procumbent poisonous subshrub having fruit that splits into five spiny nutlets.
— synonyms: devil's_weed, Tribulus_terestris
noun a plant of the genus Trapa bearing spiny four-pronged edible nutlike fruits.
— synonyms: water_chestnut, water_chestnut_plant
noun Mediterranean annual or biennial herb having pinkish to purple flowers surrounded by spine-tipped scales.
— synonyms: star-thistle, Centauria_calcitrapa