Heterospory means production of two different sizes of spores-megaspore and microspore. All bryophytes are homosporous. Heterospory originated in some pteridophytes like Selaginella. It is commonly called clubmoss or spike moss. Its leaves contain a flap-like outgrowth at the base on the adaxial side called ligule. The leaves are of two types - megasporophyll bearing megasporangia and microsporophylls bearing microsporangia. The megasporangia contains four large megaspores and the microsporangia contains large number of small microspores. Thus Selaginella is heterosporous. In some species of Selaginella the embryo remains attached to the sporophyte for a long time and it is the habit towards seed habit.