Algae are NOT plants, they belong to the Protista kingdom. Some Algae belong to the Monera kingdom. Fungi are NOT plants, they belong to the Fungi kingdom. Lichens are NOT plants. Lichens are put in the Fungi kingdom.
Ferns ARE non-flowering vascular plants.
These plants don't have flowers so they cannot have seeds. All other plants, except the above groups, grow flowers and have seeds. Even trees and grasses have flowers. The flowers of grasses, and some other plants, don't look like regular flowers but they are real flowers.