Understanding the evolutionary leap from non-flowering (gymnosperms) to flowering (angiosperms) plants and the origin and vast diversification of the floral form has been one of the focuses of plant ...

Gymnosperms diverged from their sister plant clade of flowering plants 300 Mya. Morphological and functional divergence between the two major seed plant clades involved significant changes in their ...

This paper includes a survey of the nature of the primary vascular system in a large number of extinct gymnosperms and progymnosperms. The vascular system of a majority of these plants resembles ...