Correct, and as these plants tend to grow in large groups and are all experiencing the same environmental conditions at the same time, it is quite common to have lots all flowering at the same time. The life of these flowers varies from one to four days before they melt.
In saying this, sexual reproduction seems to be the secondary form of reproduction in Crypts. Most are produced by plantlets on runners from the parent plants. Seed is likely to be a way of spreading itself as the plants grow in boggy and seasonally submersed areas where the flow of water will help distribute the seed pods.