=== พืชมีท่อลำเลียง ===
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.
Many vascular plants, however, still disperse using spores. They include two extant groups:
* [[Lycopodiophyta]] ([[
* [[Pteridophyta]] (
ferns, whisk ferns, and [[ horsetail]] s)
Other groups, which first appeared towards the end of the Paleozoic era, reproduce using [[desiccation]]-resistant capsules called [[seed]]s. These groups are accordingly called [[spermatophyte]]s or seed plants. In these forms, the gametophyte is completely reduced, taking the form of single-celled [[pollen]] and [[ovum|ova]], while the sporophyte begins its life enclosed within the seed. Some seed plants may even survive in extremely arid conditions, unlike their more water-bound precursors. The seed plants include the following extant groups: