It was in the Jurassic period when the Angiosperms first appeared on the globe. In the early Cretaceous the Angiosperms were confined to areas lying between latitudes 45°N and 45°S. The angiospermic flora was gradually replacing the non-flowering vegetation of the Jurassic and in the northern part of the globe Angiosperms established themselves only in late Cretaceous period. Teslenko proved [...]
Embryology in Taxonomy: Embryology is the study of the process of formation of embryo in a fertilised ovule, i.e., the study of the changes taking place in an ovule before and after the fertilisation. In other words, it is the study of: (a) Micro- and macro-sporogenesis in the diploid generation, (b) Micro- and mega-gametophytes in the haploid generation and (c) [...]
Plant Kingdom of Angiospermae: The vegetative cover of the earth including plants that grow under water is estimated to comprise about 393700 species. The number of species under different major groups is roughly given below: The above grouping of the plant kingdom represents the traditional classification. A recent classification based on the study of phylogeny of plants has been proposed [...]