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 [...]
This article provides a summary on Views Regarding the Time of Origin of Earliest Angiosperm. We have to depend almost entirely upon fossil evidence for the determination of the first traces of angiosperms. Unfortunately, due to lack of proper fossil records, palaeobotanical studies have not been able to solve the mystery about the earliest angiosperms. There are several views regarding [...]
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 [...]