Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
Small, feathery thing is Myriophyllum, Parrots Feather. It could fill the surface. Stems under the water.
Yellowish leaves, low on the water, right is Pistia stratioides, Water Lettuce. Thrives in warm weather. It also can fill the surface. Makes dense rosettes. Roots hang down into the water.
Tall, grassy thing could be any of several plants, one of the water Irises, perhaps. There are other possibilities.
The wide leafed item does look like one of the African Mask relatives, or maybe an ornamental Taro.
Outside the pond, red leaf is Caladium. Grows from a bulb, and can be kept indoors or out in mild weather.