Those marginals marked 'hungry' are particularly good in the battle against algae. Marginals are sold in small pots repot into larger aquatic baskets using aquatic soil topped with pea gravel this will promote growth and add stability. Never use manure in a pond. Special food for aquatic plants is available. Cut back any dead foliage in the autumn to prevent it decaying which will cloud the water and harm any fish.
Autumn is also a good time to prune and divide roots.
Apium - Fool's Cress White flower. Plant in shallow water in clumps, prefers to be moist rather than fully submerged. Carex - Rushes Brown spikey flowers, some similar to a fancy grass. Well known iris strong purple with yellow throat. Large flat blooms June-July.