The following points highlight the seven hypotheses of origin of monocots. 1. According to Engler and his associates, Isoetales, Ophioglossales and a few other pteridophytes are ancestors to monocots. The herbaceous monocots have been considered to be more primitive than woody dicotyledons by them. However, this view is contradicted by the fact that, the woody habit is now generally accepted [...]
The following points highlight the three main lines of evolution in angiosperms. Angiosperm: Evolution # 1. The First Line: I. It consists of Rhoeadales, Sarraceniales, Parietales, Malvales, Geraniales, Sapindales, Rhamnales and some Tubiferales. In this case the hypogynous condition remained unchanged. II. Labiatae is the most advanced family of this line. It is characterized by fusion of sepals, petals and [...]
The below mentioned article provides a summary on Views Regarding the Origin of Angiosperms. A fundamental problem that must be dealt with is whether the angiosperms are monophyletic (i.e. a group consisting of all descendants derived from a single ancestor) or polyphyletic (i.e. a group that does not have a common ancestor). Due to inadequate fossil records, the question of [...]