hippuris

βορβόρῳ δ' ὕδωρ λαμπρὸν μιαίνων οὔποθ' εὑρήσεις ποτόν → once limpid waters are stained with mud, you'll never find a drink

Latin > English (Lewis & Short)

hippūris: ĭdis, f., = ἵππουρις,
I horsetail, a water-plant; pure Lat., equisetum, Plin. 26, 13, 83, § 132; App. Herb. 39.