Cleistogamy

Especially well known in peanuts, peas, and pansies, this behavior is most widespread in the grass family.

This efficiency makes cleistogamy particularly useful for seed production on unfavorable sites or adverse conditions.

The obvious disadvantage of cleistogamy is that self-fertilization occurs, which may suppress the creation of genetically more fit plants.

[2] Another disadvantage of self-fertilization is that it leads to the expression in progeny of deleterious recessive mutations.

However, preliminary results from Co-Extra, a current project within the EU research program, show that although cleistogamy reduces gene flow, it is not at the moment a consistently reliable tool for biocontainment; due to a certain instability of the cleistogamous trait, some flowers may open and release genetically modified pollen.