Triploid nature of endosperm is the characteristic
feature of angiosperms. However, various ploidy
levels are also observed in plants like Butomopsis sp.
(diploid), Fritillaria sp. (pentaploid), Acalypha
indica and Peperomia sp. (polyploid). In apomictic
species of Taraxacum and Erigeron the endosperm
develop autonomously, without fertilization of the
secondary nucleus (Battaglia 1963). In another apomictic
species Brachiaria setigera, the endosperm
gave rise to triploid embryos in vivo and seedlings
where six out of 675 aposporous embryo sacs of postfertilization
ovules contained endosperm-embryos
(Muniyamma 1977).