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Smith et al. (2006), the first higher-level pteridophyte classification published in the molecular phylogenetic era, considered the ferns as monilophytes, as follows: [6] Division Tracheophyta (tracheophytes) - vascular plants Subdivision Lycopodiophyta (lycophytes) - less than 1% of extant vascular plants; Sub division Euphyllophytina ...
The clubmosses and horsetails have microphylls, as in all extant species there is only a single vascular trace in each leaf. [2] These leaves are narrow because the width of the blade is limited by the distance water can efficiently diffuse cell-to-cell from the central vascular strand to the margin of the leaf. [3]
Vascular tissue is a complex transporting tissue, formed of more than one cell type, found in vascular plants. The primary components of vascular tissue are the xylem and phloem. These two tissues transport fluid and nutrients internally. There are also two meristems associated with vascular tissue: the vascular cambium and the cork cambium.
The ferns (Polypodiopsida or Polypodiophyta) are a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers.They differ from mosses by being vascular, i.e., having specialized tissues that conduct water and nutrients, and in having life cycles in which the branched sporophyte is the dominant phase.
The extinct zosterophylls have at most only flap-like extensions of the stem ("enations") rather than leaves, whereas extant lycophyte species have microphylls, leaves that have only a single vascular trace (vein), rather than the much more complex megaphylls of other vascular plants.
All other living groups of land plants have a life cycle dominated by the diploid sporophyte generation. It is in the diploid sporophyte that vascular tissue develops. In some ways, the term "non-vascular" is a misnomer. Some mosses and liverworts do produce a special type of vascular tissue composed of complex water-conducting cells. [42]
Polysporangiophytes may or may not have vascular tissue – those that do are vascular plants or tracheophytes. [ citation needed ] Prior to that, most of the early polysporangiophytes had been placed in a single order , Psilophytales, in the class Psilophyta, established in 1917 by Kidston and Lang. [ 10 ] The living Psilotaceae , the whisk ...
As shown in the cladogram below, the euphyllophytes have a sister relationship to the lycopodiophytes or lycopsids. Unlike the lycopodiophytes, which consist of relatively few presently living or extant taxa, the euphyllophytes comprise the vast majority of vascular plant lineages that have evolved since both groups shared a common ancestor ...