scouring rush: evergreen erect horsetail with rough-edged stems; formerly used for scouring utensils
horsetail: perennial rushlike flowerless herbs with jointed hollow stems and narrow toothlike leaves that spread by creeping rhizomes; tend to become weedy; common in northern hemisphere; some in Africa and South America
vasopressin: hormone secreted by the posterior pituitary gland (trade name Pitressin) and also by nerve endings in the hypothalamus; affects blood pressure by stimulating capillary muscles and reduces urine flow by affecting reabsorption of water by kidney tubules