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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 first genus, Psilotum, consists of small shrubby plants of the dry tropics commonly known as "whisk ferns". The other genus, Tmesipteris, is an epiphyte found in Australia, New Zealand, and New Caledonia. All members of Psilotaceae are vascular plants without any true roots. Rather, the plants are anchored by an underground system of rhizomes.
In plant anatomy and evolution a microphyll (or lycophyll) is a type of plant leaf with one single, unbranched leaf vein. [ 1 ] Plants with microphyll leaves occur early in the fossil record, and few such plants exist today. In the classical concept of a microphyll, the leaf vein emerges from the protostele without leaving a leaf gap.
Vascular tissue is a complex conducting 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.
Spermatophyta. A pteridophyte is a vascular plant (with xylem and phloem) that reproduces by means of spores. Because pteridophytes produce neither flowers nor seeds, they are sometimes referred to as " cryptogams ", meaning that their means of reproduction is hidden. Ferns, horsetails (often treated as ferns), and lycophytes (clubmosses ...
The gametophyte is the sexual phase in the life cycle of plants and algae. It develops sex organs that produce gametes, haploid sex cells that participate in fertilization to form a diploid zygote which has a double set of chromosomes. Cell division of the zygote results in a new diploid multicellular organism, the second stage in the life ...
Xylem is one of the two types of transport tissue in vascular plants, the other being phloem; both of these are part of the vascular bundle. The basic function of the xylem is to transport water upward from the roots to parts of the plants such as stems and leaves, but it also transports nutrients .
The tree ferns are arborescent (tree-like) ferns that grow with a trunk elevating the fronds above ground level, making them trees. Many extant tree ferns are members of the order Cyatheales, to which belong the families Cyatheaceae (scaly tree ferns), Dicksoniaceae, Metaxyaceae, and Cibotiaceae. It is estimated that Cyatheales originated in ...