Pteridophytes vs Gymnosperms (Similarities and Differences between Pteridophytes and Gymnosperms)
Pteridophytes are a group of primitive land plants belongs to Cryptogams. They are the first plant group with vascular tissue for the conduction of water and food materials and hence they are called as Vascular Cryptogams.
Gymnosperms are a group of primitive seed-producing plants of Spermatophytes (Phanerogams). They are ‘Naked-Seed’ Plants characterized by naked ovules (i.e., ovule without the ovary). The ovules of Gymnosperms are borne directly on the surface of the megasporophyl. Since ovary is absent, Gymnosperms do not produce fruits.
Pteridophytes occupy the intermediate position between Bryophytes and Gymnosperms (seed plants). Gymnosperms were believed to be originated from the Pteridophytes in the Devonian period (419 to 359 million years ago) of Paleozoic Era. Pteridophytes and Gymnosperms share many characteristics. In the previous posts, we discussed the General Characters of BryophytesPteridophytes and Gymnosperms. In this post, we will discuss the Similarities and Differences between Pteridophytes and Gymnosperms with Comparison Table.
Classification of Gymnosperms PPT (Chamberlain System of Classification of Gymnosperms – 1934)
Classification of Gymnosperms, Outline of the history of Classification of Gymnosperms, Chamberlain System of Classification of Gymnosperms, Class Cycadophyt and Coniferophyt, Order Cycadofilicales (Pteridospermales) Cycdeoidales (Bennettitles) and Cycdales, Order Cordaitales, Ginkgoales, Coniferales and Gnetales.
Classification of Gymnosperms The Chamberlain System – 1934
Brief history of the classification of Gymnosperms:
There are many systems for the classification of Gymnosperms in the literature. Robert Brown (1827) for the first time recognized Gymnosperms as a separate group of plants. Bentham and Hooker (1883) placed Gymnosperms between Dicots and Monocots in their classification (General Plantarum).
Van Tieghman (1898) gave the status of Major Division to the Gymnosperms. Tieghman also divided the whole Spermatophyta (seed plants) into two divisions namely Gymnosperms (Astigmatae) and Angiosperms (Stigmatae).
Coulter and Chamberlain in 1912 divided the division Gymnosperms directly into seven orders namely (1) Cycadofilicales, (2) Bennettitales, (3) Cycadales, (4) Cordaitales, (5) Ginkoales, (6) Coniferales and (7) Gnetales.
Classification of Gymnosperms by Chamberlain (1934)
Ø Chamberlain (1934) divided the Gymnosperms into TWO classes and each class into orders.
Ø Gymnosperms were divided into TWO classes:
Class I : Cycadophyta
Ø Class Cycadophyta includes both fossil and living forms.
Flower vs Vegetative Branch (Difference between Flower and Reproductive Shoot)
The flower is the reproductive structure formed in the plant group Angiosperms or Magnoliophyta, commonly called as the ‘Flowering Plants’. The flower is a ‘modified branch’ or axis developed from a ‘determinate’ apical meristem.
The term ‘determinate’ indicates the absence of further growth of the apical meristem after the production of flowers. Even though the flower is a modified shoot, the morphological and anatomical features of a flower and a vegetative branch show many differences.
The present post discusses the Difference between a Flower and a Vegetative Branch with a Comparison Table.