An old borrow pit fringed by willows contains an interesting aquatic flora including spiked water milfoil and common water crowfoot.
Many herbs have had the power of curing all diseases attributed to them, and have hence had the name of "all-heal"; such have been, among others, the mistletoe, the woundwort (Stachys palustris), the yarrow or milfoil, and the great valerian.
Water-cress, sweet flag, flowering rush, several potamogetons, water milfoil, water ranunculus, and the reedy sweet watergrass (Glyceria aquatica) rank amongst the criteria of excellence.
Instead of the aliens listed above, choose plants such as spiked water milfoil, rigid hornwort and water starwort as oxygenating plants.