Chasmogamous flowers produce flowers that open petals at maturity to expose the male and reproductive parts.
The open flowers help in the self-pollination process, where the pollen from the stamen of the same flower lands on the stigma of the carpel of the same flower.
Stamen is the male reproductive organ and carpel is the female reproductive organ respectively.
Some chasmogamous flowers produce closed petals that help in cross-pollination, hence having a superior genetic variability.
Different chasmogamous flowers are Hibiscus, Viola, etc.
A herbaceous plant commonly known as henbit (Lamium amplexicaule) produces both cleistogamous (closed) and chasmogamous (open) flowers on a single individual.