Certain plants, like gymnosperms, produce seeds but lack fruits. Gymnosperms, including pine trees and cycads, have exposed seeds on cone scales, distinguishing them from angiosperms, which produce seeds enclosed within fruits. The absence of a fruit covering the seed is a characteristic feature of gymnosperms, a group of seed-producing plants.

The plants that never produce flowers are called "cryptogams." Cryptogams include plants such as ferns, mosses, liverworts, and algae. Unlike flowering plants (angiosperms), which reproduce through seeds enclosed within flowers, cryptogams reproduce through spores and do not produce true flowers. Cryptogams are considered more primitive in evolutionary terms compared to angiosperms, which are the most dominant group of plants on Earth today.