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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.
A prothallus, or prothallium, (from Latin pro = forwards and Greek θαλλος (thallos) = twig) is usually the gametophyte stage in the life of a fern or other pteridophyte. Occasionally the term is also used to describe the young gametophyte of a liverwort or peat moss as well. In lichens it refers to the region of the thallus that is free ...
Polystichum setiferum, a fern Grimmia pulvinata, a moss Pelvetia canaliculata, a brown alga Hypholoma fasciculare, a fungus. A cryptogam (scientific name Cryptogamae) is a plant, in the broad sense of the word, or a plant-like organism that share similar characteristics, such as being multicellular, photosynthetic, and primarily immobile, that reproduces via spores rather than through flowers ...
A proposed phylogeny of the vascular plants after Kenrick and Crane 1997 [15] is as follows, with modification to the gymnosperms from Christenhusz et al. (2011a), [16] Pteridophyta from Smith et al. [17] and lycophytes and ferns by Christenhusz et al. (2011b) [18] The cladogram distinguishes the rhyniophytes from the "true" tracheophytes, the ...
In some phyla of fungi, the sporangium plays a role in asexual reproduction, and may play an indirect role in sexual reproduction. The sporangium forms on the sporangiophore and contains haploid nuclei and cytoplasm. [3] Spores are formed in the sporangiophore by encasing each haploid nucleus and cytoplasm in a tough outer membrane.
For further information, see Red algae: Reproduction. Land plants all have heteromorphic (anisomorphic) alternation of generations, in which the sporophyte and gametophyte are distinctly different. All bryophytes , i.e. liverworts , mosses and hornworts , have the gametophyte generation as the most conspicuous.
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 nomenclature and classification of plants with microphylls varies substantially among authors. A consensus classification for extant (living) species was produced in 2016 by the Pteridophyte Phylogeny Group (PPG I), which places them all in the class Lycopodiopsida, which includes the classes Isoetopsida and Selaginellopsida used in other ...