Selaginella is the only genus of vascular plants in the family Selaginellaceae , the spikemosses or lesser clubmosses .
This family is distinguished from the Lycopodiaceae (Clubmoss), which have scaly-leaves with a ligule and two types of spores . They are sometimes included in an informal paraphyletic group known as ” fern allies “. S. moellendorffii is an important model organism . Its genome was sequenced from the United States Department of Energy ‘s Joint Genome Institute . [1] The name Selaginella was coined by Palisot de Beauvois for the only species Selaginella selaginoides , which (with the closely related Selaginella deflexa ) was coined) to be a clade that is sister to all other Selaginellas , so any certain subdivision of species in the separate genera leaves the two taxa in Selaginella , with hundreds of other species in new or revived genera.
Selaginella occurs mostly in tropical regions of the world, with a handful of species found in arctic-alpine regions of both hemispheres.
Description
Selaginella species are creeping or climbing plants with simple, scale-like leaves ( microphylls ) on branched stems from which roots also emerge. The stems are aerial, creeping horizontally at the base (as in Selaginella crosiana ), sub-erect ( as in Selaginella trachyphila ) or upright ( as in Selaginella erythropus ). Vascular steles are polystelic protosteles . The stem segment shows the presence of more than two protosteles. Each stele diarch (center of origin inwards, subsequent cells are centrifuged) and exarchComposed of xylem (centre of origin located later, later cells are added to the center). [ clarification needed ] [ citation needed ] Stells are connected to the cortex via several tube-like structures called trabeculae , which are modified endodermal cells with Casparian strips on their lateral walls. [ citation needed ] The stems have no pith. [ citation needed ]
Unusually for lycopods, which usually have microphylls with an unbranched vein, the microphylls of Selaginella species contain a branched vascular notch. In Selaginella , each microphyll and sporophyll is the result of a small scale-like result called a ligule at the base of the upper surface. [3] : 7 Plants are heterospores with two different size classes of spores , known as megaspores and microspores.
In dry conditions, some species of Selaginella can survive dehydration. At this stage, they may roll over and dislodge a brown ball, but can reactivate in moist conditions, turn green again, and resume growth. This phenomenon is known as poikilohydry, and poikilohydric plants such as Selaginella bryopteris are sometimes referred to as resurrection plants .
Classification
Some scientists [ who? ] still place Selaginellales in the Lycopodiopsida class (often misunderstood as “Lycopsida”). [ citation needed ] Some modern authors recognize three general divisions of Selaginella : Selaginella , Bryodesma Sojak 1992 , and Lycopodioides ( Böhm 1760 ) . Lycopodioides includes the North American species S. Apoda and S. eclipse , while Bryodesma will contain S. Rupestris (as Bryodesma rupestre ). Stachygynandrum is also sometimes used to include the bulk of the species. [ citation needed ]
The first major attempt to define and subdivide the group was by Palisot de Beauvois [4] in 1803–1805 . He established the genus Selaginella as a monotypic genus, and placed the bulk of the species in Stachyginandrum . Gymnogynum was another monotypic genus, but that name has been dropped from its earlier name of Didiclis . This turns out, today, to be a group of around 45-50 species also known as Articulatae since its lineage, Didiclis / Gymnogynum , was based on Selaginella plumosa . He Selaginella ApodaThe genus Diplostachium has also been described to include a group of species such as . The spring genus inflated Selaginella to hold all selaginelloid species four decades later.
Phylogenetic studies by Korall and Kenrick [5] [6] have determined that the Euselaginella group, the only type species containing Selaginella selaginoides and a closely related Hawaiian species, Selaginella deflexa , is a basal and divergent sister in antiquity to all other Selaginella . species. In addition, their study divided the remaining species into two broad groups, one containing the Bryodesma species, Articulatae , section Erysatorum jermi and others, and the other focused on the broader Stachyginandrum group.
Walton and Aston Classification
In The Manual of Pteridology , [7] the following classification was used by Walton and Alston:
Genus: Selaginella
- Subtype : Euselaginella
- Group: Selaginoids
- Group: Pygmea
- Group: uliginosa ( Ericatorum )
- Group: rupestris ( Tetragonostachys or Bryodesma )
- Subtype : Stachigyanandram
- Series: Decumbantes
- Series: Ascendant
- Series: Sarmentosse
- Series: ColeSantis
- Series: Circintai
- Series: Addition
- Subspecies : Homeostachis
- Subspecies : Heterostachis
However, it is now known to be highly paraphyletic in most of its groups. Two recent classifications, which employ modern methods of phylogenetic analysis, are as follows:
Weststrand and Coral, 2016 Classification
Genus: Selaginella
- Subtype : Selaginella
- Clade: “Rhizophoric Clade”
- Clade A
- Subgenus Rupestre [ Bryodesma sojak or Tetragonostachis jermi , S section Homophila ]
- Subgenus Lepidophila [ S section Lepidophila ]
- Subgenus Gymnogynum [ S section articulatae ]
- Subgenus Exaltatae [w. S section Megalosporum , S section Myosurus ]
- Subgenus Erysetorum [ S section Laealia ]
- Clade B
- Subgenus Stachyginandrum [incl. s. ( Boroselaginella ), S. ( Pulvinella ), S. ( Heterostachys )]
- Clade A
Zhang and Zhou, 2015 Classification
Genus: Selaginella
- Subspecies: Selaginella Type: S. selaginoides (L.) P.Beauv. East Mart. srank
- Subgenus: Boroselaginella type: S. Senginolenta (L.) Spring
- Subgenus: Erisitorum Type: S. Euliginosa (Lab.) Spring
- Section: Lyalia Type: S. uliginosa (Lab.) Spring
- Section: Myosurus Type: S. myosurus Alston
- Section: Megalosporum Type: S. exaltata (Arrow) Spring
- Section: Articulaetae Type: S. cruciana (keys) A. Braun
- Section: Homoeophyllae Type: S. rupestris (L.) Spring (= Bryodesma Sojak or Tetragonostachys Jermy )
- Section: Lepidophila Type: S. Lepidophila ( Hook and Grev .) Spring
- Subgenus: Pulvinella Type: S. pulvinata (Hook and Grev.) Maxim
- Subspecies : Heterostachys Type : S. heterostachys baker
- Section: Oligomacrosporangiatae Type: Selaginella uncinata (Desv. ex Poir.) Spring
- Section: Auriculate Type: S. Douglas (Hook and Grev.) Spring
- Section: Homeostachis Type: : S. helvetica (L.) Link
- Volume: Tetragonosta type: S. Proniflora (L.) baker
- Section: Heterostachys Type: S. Brachystachys (Hook and Grev.) Spring
- Subgenus: Stachygnandrum Type: S. flabellata (L.) Spring
- Section: Plagiophila Type: S. Biformis A. _ braun ex kuhn
- Section: Circintie Type: S Included (Self.) Spring
- Section: Heterophila Type: S. flexuosa spring
- Section: AustroAmericana Type: S. Hartwegiana Spring
- Section: Palasentis Type: S. Palascens (C.Pressl) Spring
- Section: Processes Type: S. Oaxacana Spring
- Section: Ascendentes Type: S. alopecuroides Baker
Caste
There are about 750 known species of Selaginella . [10] They feature a wide range of characters; The genus is overdue for a modification that may include subdivision into several species. [ citation needed ] Better known [ By whom? ] Spikemoss contains:
- Selaginell apoda – meadow spikemoss; Eastern North America
- Selaginell arizonica maxon – from West Texas to Arizona and Sonora, Mexico
- Selaginell espresso
- Selaginell bifida – Rodrigues Island
- selaginell biformis
- selaginell bigelowii
- Selaginell Bruni – Braun’s Spikemoss ; China
- Selaginell Bryopteris – Sanjivani; India
- Selaginella canaliculata – clubmoss; Southeast Asia, Maluku Islands
- selaginell carinata
- selaginell cinerescens
- Selaginell densa – low spikemoss; western north america
- Selaginell denticulata
- Selaginell Eclipse – Hidden Spikemoss; Eastern North America
- selaginell elmeri
- Selaginell Eremophila Maxon
- selaginell erythropus
- selaginell galotei
- Selaginell Hanseni
- Selaginell crosiana – spikemoss of the cross; Africa, Azores
- Selaginell lepidophila – resurrection plant, dinosaur plant, and stone flower; Chihuahuan Desert, North America
- Selaginell martensi – a variety of spikemoss
- selaginell moellendorffic
- selaginell oregano
- Selaginell plana – Asian spikemoss; tropical asia
- Selaginell Poultry
- Selajinela in Pulcherry
- Selaginella rupestris – rock spikemoss, pylon pine, and northern Selaginella (eastern North America)
- Selaginell Rupincola Underv . – West Texas to Arizona and Sonora, Mexico
- Selaginell selaginoides – lesser clubmoss; North Temperate Europe, Asia and North America)
- Selaginell sericea A.Braun –
- Selaginell serpence
- selaginell sibirica
- Selaginell stellata – starry spikemoss; Mexico, Central America
- Selaginell Substipitata
- selaginell tamarind
- Selaginell tortipila
- Selaginell euliginosa – Australia
- Selaginell ambrosa
- Selaginell uncinata – peacock moss, peacock spikemoss, blue spikemoss
- Selaginell Underwoodi Hiron. – West Texas to Wyoming and West to Arizona
- selaginell wallacei
- selaginell watsoni
- Selaginell vildenovii – Vildeno’s spikemoss, peacock fern; Southeast Asia
Some species of Selaginella are desert plants known as “resurrection plants”, because they curl into a tight, brown or red ball during dry times, and flutter and become green in the presence of moisture. Other species are tropical forest plants that at first glance appear as ferns.
Farming
Several Selaginella species are popular plants for cultivation, mostly tropical species. Some of the species that are popularly cultivated and actively available commercially include:
- S. cruciana : Golden Clubmoss
- S. moellendorffii : Gemiferous spikemoss
- S. erythropus : red selaginella or ruby-red spikemoss
- s. Uncinata : Peacock Moss
- S. lepidophila : plant of the resurrection
- S. Brownie : Arborvitae Fernie
