Final answer:
The Horsetail (Equisetum) is the eusporangiate fern with air channels that allow it to live in flooded environments.
Step-by-step explanation:
The type of eusporangiate fern that has air channels allowing it to live in flooded environments is the Horsetail (Equisetum). Horsetails belong to the phylum Monilophyta and are placed in the class Equisetopsida. These plants have adapted to survive in damp environments and marshes, which indicates their ability to deal with flooded conditions. Horsetails are known for their distinctiveness, with their vertical branches having a unique pattern of growth and their photosynthetic stems equipped to survive in wet habitats.