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In a vascular plant, the stele is the central part of the root or stem [1] containing the tissues derived from the procambium. These include vascular tissue, in some cases ground tissue and a pericycle, which, if present, defines the outermost boundary of the stele.
Pteridospermatophyta, also called "pteridosperms" or "seed ferns" are a polyphyletic [1] grouping of extinct seed-producing plants.The earliest fossil evidence for plants of this type are the lyginopterids of late Devonian age. [2]
Stellar evolution is the process by which a star changes over the course of its lifetime and how it can lead to the creation of a new star. Depending on the mass of the star, its lifetime can range from a few million years for the most massive to trillions of years for the least massive, which is considerably longer than the current age of the ...
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.
In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), Lycopodium is one of nine genera in the subfamily Lycopodioideae, and has from nine to 15 species. [1] [4] In other classifications, the genus is equivalent to the whole of the subfamily, since it includes all of the other genera. More than 40 species are accepted. [5]
The Pteridophyte Phylogeny Group classification of 2016 (PPG I) recognized 13 genera. [5] Shortly afterwards, the genus Gastoniella was created for three species formerly placed in Anogramma which a molecular phylogenetic analysis had shown to be distinct.
All of these are recognized by the Pteridophyte Phylogeny Group classification of 2016 (PPG I), except for the genus Brownseya, described in 2021. [2] Other classifications circumscribe the genera in the family more broadly, recognizing the subfamilies Lycopodielloideae, Lycopodioideae, and Huperzioideae as the genera Lycopodiella , Lycopodium ...
The Pteridophyte Phylogeny Group (PPG) is an informal international group of systematic botanists who collaborate to establish on the classification of pteridophytes (lycophytes and ferns) that reflects knowledge about plant relationships discovered through phylogenetic studies. In 2016, the group published a classification for extant ...