Step 1: Understanding the plant characteristics
Salvinia: A free-floating hydrophyte with no contact with the soil (I).
Utricularia: An insectivorous plant and free-floating hydrophyte (II).
Vallisneria: A submerged rooted hydrophyte with stomata absent (III).
Typha: An amphibious plant that lives partly in water and partly in the air (IV). Final Answer: \[
I, III\text{ and }IV
\]