Three groups of plant that bear archegonia are
1. Bryophyta,
2. Pteridophyta and
3. Gymnosperm.
Life cycle of gymnosperms : The gymnosperms are heterosporous, they produce haploid microspores and megaspores. The two kinds of spores are produced within sporangia that are borne on sporophyll which are arranged spirally along an axis to form strobili or cones. The strobili bearing microsporophylls and microsporongia are called microsporangiate or male strobili. The microspores develop into a male gametophytic generation which is highly reduced, and confined to only limited number of cells. The reduced gametophyte is called pollen grain. The development of pollen grain takes place within microsporangia. The cones bearing megaspo-rophylls with
ovules or megasporangia are called macrosporangiate or female strobili. The male or female cones or strobili may be borne on the same tree or different trees. The megaspore mother cell is differentiated from one of the cells of the nucellus. The nucellus is protected by envelopes and the composite structure is called an ovule. The ovules are borne on megasporophylls which may be clustered to form the female cones. The females cones are borne on the main plant body of the sporophyte. The megaspore mother cell divides meiotically to form four megaspore. One of the megaspore enclosed within the megasporangium develops into multicellular female gametophyte that bears 2 or more archegonia or female sex organs. The multicellular female gametophyte is also remains within megasporangium.