ผลต่างระหว่างรุ่นของ "พืชบก"

{{Taxobox

| name = พืชบก

| image = Fern.jpg

| image_width = 250px

| subdivision_ranks = ส่วน

| subdivision =

** [[Marchantiophyta]] - ลิเวอร์เวิร์ต

** [[Anthocerotophyta]] - ฮอร์นเวิร์ต

** [[มอสส์|Bryophyta]] - มอสส์

** †[[Horneophytopsida]]

** †[[Rhyniophyta]]—rhyniophytes

** †[[Zosterophyllophyta]]—zosterophylls

** †[[Trimerophytophyta]]—trimerophytes

** [[fern|Pteridophyta]] - เฟิร์น

*** †[[Pteridospermatophyta]] - เฟิร์นมีเมล็ด

*** [[Pinophyta]] - สน

Embryophytes developed from complex [[green alga]]e ([[Chlorophyta]]) during the [[Paleozoic]] era. The [[Charales]] or stoneworts appear to be the best living illustration of that developmental step. These alga-like plants undergo an [[alternation of generations|alternation]] between [[haploid]] and [[diploid]] generations (respectively called [[gametophyte]]s and [[sporophyte]]s).

 

In the first embryophytes, however, the sporophytes became very different in structure and function, remaining small and dependent on the parent for their entire brief life. Such plants are informally called '[[bryophytes]]'. They include three surviving groups:

 

All of the above 'bryophytes' are relatively small and are usually confined to moist environments, relying on water to disperse their [[spore]]s.

 

Other plants, better adapted to terrestrial conditions, appeared during the [[Silurian]] period. During the [[Devonian]] period, they diversified and spread to many different land environments, becoming the [[vascular plant]]s or [[Tracheophyta|tracheophytes]]. Tracheophyta have vascular tissues or [[tracheid]]s, which transport water throughout the body, and an outer layer or cuticle that resists [[desiccation|drying out]]. In most vascular plants, the sporophyte is the dominant individual, and develops true [[leaf|leaves]], [[Plant stem|stems]], and [[root]]s, while the gametophyte remains very small.

 

The first four groups are referred to as [[gymnosperm]]s, since the embryonic sporophyte is not enclosed until after pollination. In contrast, among the flowering plants or [[angiosperm]]s, the pollen has to grow a tube to penetrate the seed coat. Angiosperms were the last major group of plants to appear, developing from gymnosperms during the [[Jurassic]] period, and then spreading rapidly during the [[Cretaceous]]. They are the predominant group of plants in most [[Terrestrial plant|terrestrial]] [[biome]]s today.

 

Note that the higher-level [[Statistical classification|classification]] of plants varies considerably. Some authors have restricted the [[Kingdom (biology)|kingdom]] [[Plantae]] to include only embryophytes, others have given them various names and ranks. The groups listed here are often considered divisions or [[phylum|phyla]], but have also been treated as classes, and they are occasionally compressed into as few as two divisions. Some classifications, indeed, consider the term Embryophyta at the superphylum (superdivision) level, and include Land Plants and some Charophyceae in a subkingdom named [[Streptophyta]].

 

* Kenrick, Paul & Crane, Peter R. (1997). ''The Origin and Early Diversification of Land Plants: A Cladistic Study''. Washington, D. C.: Smithsonian Institution Press. ISBN 1-56098-730-8.

* Raven, Peter H., Evert, Ray F., & Eichhorn, Susan E. (2005). ''Biology of Plants'' (7th ed.). New York: W. H. Freeman and Company. ISBN 0-7167-1007-2.

* Stewart, Wilson N. & Rothwell, Gar W. (1993). ''Paleobotany and the Evolution of Plants'' (2nd ed.). Cambridge: [[Cambridge University Press]]. ISBN 0-521-38294-7.

* Taylor, Thomas N. & Taylor, Edith L. (1993). ''The Biology and Evolution of Fossil Plants''. Englewood Cliffs, NJ: Prentice Hall. ISBN 0-13-651589-4.