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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 ...
An interesting case is that of Psilotum, which has a (simple) protostele, and enations devoid of vascular tissue. Some species of Psilotum have a single vascular trace that terminates at the base of the enations. [2] Consequently, Psilotum was long thought to be a "living fossil" closely related to early land plants (rhyniophytes).
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.
They are one of the oldest lineages of extant (living) vascular plants; the group contains extinct plants that have been dated from the Silurian (ca. 425 million years ago). [ 2 ] [ 3 ] Lycophytes were some of the dominating plant species of the Carboniferous period, and included the tree-like Lepidodendrales , some of which grew over 40 metres ...
Non-vascular plants are plants without a vascular system consisting of xylem and phloem. Instead, they may possess simpler tissues that have specialized functions for the internal transport of water. Instead, they may possess simpler tissues that have specialized functions for the internal transport of water.
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.
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 ...