What is the difference between Gymnosperms & Pteridophytes?

(1) Gymnosperms are commonly large sized trees, shrubs or climbers and exhibit xeric characters. Pteridophytes on contrary are relatively smaller in size and are more commonly hygroscopic.

(2) Both gymnosperms and pteridophytes differ in external and internal characters of sporophytes:

i. Gymnosperms are characterized by the presence of tap roots whereas the roots of pteriodophytes are adventitious.

ii. Gymnosperms possess aerial stem, where as stem of pteridophytes (ferns) are mostly underground.

iii. Gymnosperms have eustelic organization, whereas in pteridophytes eustele is not found.

iv. Excessive secondary growth occurring in higher gymnosperms (conifers) is a distinct anatomical advancement over the pteridophytes.

(3) In gymnosperms, male and female gametophytes are simple, non-green and dependent on the sporophytes. They are very much reduced in comparison to the gametophytes of pteridophytes.

(4) In all living gymnosperms, pollen tube develops as a result of germination of pollen grains. Such a structure does not occur even in the heterosporous pteriodophytes.

(5) In gymnosperms, microspores, that are light and wind dispersed, are shed from the sporophyte soon after their particle development and come to lie on the exuding nucellus from the micropyle. In pteridophytes on the other hand microspores may or may not germinate in situ and male cells move in presence of water.

(6) In gymnosperms, megaspores remain in the megasporangium, whereas, in pteridophytes they are shed from the sporangia and develop into independent female prothallus.

(7) Archegonial neck in gymnosperms is very small and lacks neck canal cells and venter canal cell. Archegonia are provided with neck canal cells and venter canal cell in pteridophytes. Gnetum lacks archegonia.

(8) Seed formation is not common in pteridophytes (except Selaginella), whereas, in gymnosperms seeds are produced.