Selaginella apoda

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Meadow spikemoss
Selaginella apoda3.jpg
Status TNC G5.svg
Secure  (NatureServe) [1]
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Lycophytes
Class: Lycopodiopsida
Order: Selaginellales
Family: Selaginellaceae
Genus: Selaginella
Species:
S. apoda
Binomial name
Selaginella apoda
Synonyms

Diplostachyum apodum
(L.)  P.Beauv.
Lycopodioides apoda(L.)  Kuntze
Lycopodium albidulum Sw.
Lycopodium apodumL.
(basionym)
Selaginella albidula(Sw.) Spring

Contents

List sources : [3]

Selaginella apoda, commonly known as meadow spikemoss, [4] is a perennial lycophyte native to much of the eastern United States and parts of northeastern Mexico. The life cycle is the shortest of the genus Selaginella, as well as one of the shortest among the lycophytes. Selaginella apoda is found primarily in damp soils in habitats such as swamps, wet fields, open woods and along stream banks. Selaginella apoda presents the potential for case studies involving the plant's adaptability to environmental toxins. It is closely related to Selaginella eclipes and S. ludoviciana , with both of which it has been reported to form hybrids. This group is characterized by relatively flat strobili and large megasporophylls which occur in the same plane as the lateral leaves. [5]

The plant was originally described, and named Lycopodium apodum by Carl Linnaeus in his Species Plantarum (1753). [2]

Description

Selaginella apoda Krakow.JPG

Selaginella apoda stems have smaller leaves in two rows as well as larger leaves in two rows. [6] This species can be differentiated from a regular moss species based on its veins running along the leaves. [7] The stem of S. apoda can best be described as leafy. [6] Selaginella species possess rhizophores. [6]

Many species in the genus Selaginella also demonstrate dichotomous branching. Vegetative leaves on S. apoda are lined with small teeth, have a scale-like appearance, are short in length, and change in shape and size in the same node. Selaginella apoda branches can be a maximum of 15 centimeters in height and have a creeping style. The ligule on Selaginella species can be found rising on the adaxil surfaces of leaves at their base, as well as on sporophylls. The shape of the ligule is awl-shaped and occurs singly. The leaves of S. apoda contain a cuticle layer on their adaxial surfaces and they do not have hairs on their abaxial surfaces. [6]

The internodes of S. apoda branches can be used to classify the branches as reproductive or vegetative, as the internodes are extended on vegetative branches. Selaginella apoda adventitious and primary roots contain a root cap at their tips, have the ability to branch when growing, are white, and possess root hairs, located in close proximity to the tips. Selaginella apoda primary root system contains only three single root strands; as such, the system is ailing, for it also does not branch significantly. Adjacent to the axil, sporangia are created from artificial cells. [6] While stomata can be found following the leaf margin on the lower surface of the plant's leaves, stomata on the upper surface of S. apoda leaves disperse entirely [6] following the laminae. [8]

The dorsal leaves of S. apoda have acuminate apices. [9] The primary leaves of S. apoda significantly contrast in shape from the cotyledons of the plant. Selaginella apoda leaf blades have borders with a margin that is light green in appearance or simply identical to each other. The strobilus of S. apoda is often restricted to a length of 1-2 centimeters. [9] Typically, the strobili of S. apoda are in an erect position. Within the sporangia, the two gametophyte forms start development. Selaginella apoda sporangia can be distinguished from other species of Selaginella in how its wall is composed of two layers instead of three. [6]

Taxonomy

The species was first described by Carl Linnaeus in 1753 as Lycopodium apodum. The specific epithet apodum is the neuter form of an adjective apodus, coined by Linnaeus, meaning "footless". When in 1840 Antoine Frédéric Spring transferred it to the genus Selaginella , he did so under the name Selaginella apus, apus being a noun used in apposition rather than Linnaeus's adjective, on the grounds that in classical Latin, there is no such adjective as apodus. In 1915, Merritt Lyndon Fernald published the name Selaginella apoda, following Linnaeus in using an adjective as the specific epithet, in this case agreeing in gender with the feminine noun Selaginella. Both names have been used. [10]

Selaginella apoda falls under the order Selaginellales and the family Selaginellaceae, [11] the biggest family of the lycophytes group and of which Selaginella is the single genus. [6] The lycophytes contain over 1000 species across 10-15 extant genera. In the order Selaginellales, Selaginella also is the only living genus. [6] Approximately 700-800 species comprise the genus Selaginella [12] worldwide, of which about 320 can be found in the Western Hemisphere alone. [9] Selaginella apoda is a synonym for Lycopodioides apoda [11] as well as Lycopodium apodum. [13] This plant species was named based on Linnaeus' observation that its strobili were stalkless. [6]

Selaginella apoda can be subcategorized into the subgenus Stachygynandrum. [6] The genus Selaginella has been subjected to taxonomic treatments, including the arrangement of a plant's sporangia as well as the types of spores the plant species produces. [9] In terms of phylogenetics, S. apoda falls under the S. pallescens OPHA clade, species that are native to the American continent and have one type of sporophyll in the form of a megaspore network. [12] In the family Selaginellaceae, microsporangia are larger than the megasporangia and the strobili are quadrangular in shape or flat. [13] Selaginella apoda, under the synonymous name of Lycopodium apodum, can be identified by stomata spread across the plane of the adaxial sides of its leaves, the leaf margins of the plant are all similar to each other, the diameter of their megaspores within the range of 0.29 – 0.35 millimeters, and the plant has acute to attenuate apices on at least 5 of their leaves. [13]

Distribution and habitat

Minus Antarctica, Selaginella species can be found scattered across the world's continents. [12] Selaginella apoda occurs naturally in the Midwestern and Eastern states of the United States. [6] In the Americas, S. apoda can be found as far north as the U.S. state of Maine to as far south as Guatemala. [6]

While studies show that it can be located across U.S. States bordering the Gulf of Mexico, greater populations occur in the Cumberland Mountains, the larger Appalachian Mountains range, and the piedmonts of these states rather than directly in coastal environments. [6] It can grow along lake or river shores, in meadows, human-disturbed habitats, as well as in aquatic habitats such as rivers. [7] Primarily, Selaginella apoda thrives in environments heavily shaded from the sun and with high moisture content in the soils. [6] Such environments can include the edges of wetland marshes, oceanic cliffs, wetland meadows, bogs, along the banks of running streams, or any similar saturated environment. [13]

Boron effects on Selaginella

In a study testing the effects of boron on Selaginella species, the sporophyte heights in S. apoda demonstrated important contrasts between specimens treated with a small dose of boron and specimens without chemical treatment. [14] The S. apoda specimens that lacked treatment with boron resulted in a yellow-green pigmentation and reduction in size, while the plant specimens chemically treated with boron demonstrated their expected green pigmentation as well as normal size. Selaginella apoda tested in the study demonstrated strobili reductions of ¼ its normal length in specimens not treated with boron than specimens treated with boron, and the boron-treated plants experienced abortion in their strobili. In the growth stages of S. apoda, boron influences reproduction. [14]

Ecology

Tropical regions have diverse Selaginella floras. [12] Selaginella hybrid species are rare because they do not have spore dispersal methods that allow for scattering of them across great distances. [8] Selaginella apoda megaspores may be dispersed by wind or water. It may take as few as 85 days for S. apoda to finish its life cycle. In relation to the life cycle of other species of the genus Selaginella, this time frame is much briefer. [6]

While scientists have already concluded that the life cycle span of S. apoda is reliant in large part on the temperature of its habitat, researchers suggest that the duration of daylight may play a key role in determining the duration of the S. apoda life cycle as well. The primary root system of S. apoda is fragile. The root hairs are able to live on the roots for months and are mature on the roots prior to the root system penetrating the soil in the early growth stages. The roots, angle meristems, as well as rhizophores of S. apoda experience supplemental growth as the plant itself increases in height. This additional growth occurs in order to ensure the species does not have to transfer water in abundance while still being able to grow across a vast surface plane. [6]

The lower surface on dorsal leaves of S. apoda, as well as the upper surface of its ventral leaves, experience sunlight exposure if the stem of the plant experiences creeping growth, while the dorsal leaves' upper surfaces and the ventral leaves' lower surfaces are pointed away from direct light exposure. Strobilus length, as well as microsporangia counts, in S. apoda are reliant on their development season in addition to the strobilus' age. Typically, S. apoda is prostrate, meaning that it lays flat on the ground. [6]

Cultivation

Due to S. apoda's simple requirements, as well as its life cycle being so short in comparison to other Selaginella species, the plant is considered a model species suitable for related scientific studies. [6]

Related Research Articles

<span class="mw-page-title-main">Gametophyte</span> Haploid stage in the life cycle of plants and algae

A gametophyte is one of the two alternating multicellular phases in the life cycles of plants and algae. It is a haploid multicellular organism that develops from a haploid spore that has one set of chromosomes. 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 cycle known as the sporophyte. The sporophyte can produce haploid spores by meiosis that on germination produce a new generation of gametophytes.

<span class="mw-page-title-main">Sporangium</span> Enclosure in which spores are formed

A sporangium ; pl.: sporangia) is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. Virtually all plants, fungi, and many other groups form sporangia at some point in their life cycle. Sporangia can produce spores by mitosis, but in land plants and many fungi, sporangia produce genetically distinct haploid spores by meiosis.

<span class="mw-page-title-main">Lycopodiopsida</span> Class of vascular plants

Lycopodiopsida is a class of vascular plants also known as lycopods or lycophytes. Members of the class are also called clubmosses, firmosses, spikemosses and quillworts. They have dichotomously branching stems bearing simple leaves called microphylls and reproduce by means of spores borne in sporangia on the sides of the stems at the bases of the leaves. Although living species are small, during the Carboniferous, extinct tree-like forms (Lepidodendrales) formed huge forests that dominated the landscape and contributed to coal deposits.

<i>Selaginella</i> Genus of vascular plants in the family Selaginellaceae

Selaginella, also known as spikemosses or lesser clubmosses is a genus of lycophyte. It is usually treated as the only genus in the family Selaginellaceae, with over 750 known species.

<i>Isoetes</i> Genus of vascular plants in the family Isoetaceae

Isoetes, commonly known as the quillworts, is a genus of lycopod. It is the only living genus in the family Isoetaceae and order Isoetales. There are currently [when?] 192 recognized species, with a cosmopolitan distribution mostly in aquatic habitats but with the individual species often scarce to rare. Species virtually identical to modern quillworts have existed since the Jurassic epoch, though the timing of the origin of modern Isoetes is subject to considerable uncertainty.

<span class="mw-page-title-main">Lycopodiaceae</span> Family of vascular plants

The Lycopodiaceae are an old family of vascular plants, including all of the core clubmosses and firmosses, comprising 16 accepted genera and about 400 known species. This family originated about 380 million years ago in the early Devonian, though the diversity within the family has been much more recent. "Wolf foot" is another common name for this family due to the resemblance of either the roots or branch tips to a wolf's paw.

<i>Lycopodium</i> Genus of vascular plants in the family Lycopodiaceae

Lycopodium is a genus of clubmosses, also known as ground pines or creeping cedars, in the family Lycopodiaceae. Two very different circumscriptions of the genus are in use. In the Pteridophyte Phylogeny Group classification of 2016, Lycopodium is one of nine genera in the subfamily Lycopodioideae, and has from nine to 15 species. 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.

<span class="mw-page-title-main">Sporophyll</span>

A sporophyll is a leaf that bears sporangia. Both microphylls and megaphylls can be sporophylls. In heterosporous plants, sporophylls bear either megasporangia and thus are called megasporophylls, or microsporangia and are called microsporophylls. The overlap of the prefixes and roots makes these terms a particularly confusing subset of botanical nomenclature.

<i>Lycopodium clavatum</i> Species of vascular plant in the family Lycopodiaceae

Lycopodium clavatum is the most widespread species in the genus Lycopodium in the clubmoss family.

<i>Lycopodiella</i> Genus of spore-bearing plants

Lycopodiella is a genus in the clubmoss family Lycopodiaceae. The genus members are commonly called bog clubmosses, describing their wetland habitat. The genus has a cosmopolitan distribution, with centers of diversity in the tropical New World and New Guinea. In the past, the genus was often incorporated within the related genus Lycopodium, but was segregated in 1964. In the Pteridophyte Phylogeny Group classification of 2016, Lycopodiella is placed in the subfamily Lycopodielloideae, along with three other genera. In this circumscription, the genus has about 15 species. Other sources use a wider circumscription, in which the genus is equivalent to the Lycopodielloideae of PPG I, in which case about 40 species and hybrids are accepted.

A strobilus is a structure present on many land plant species consisting of sporangia-bearing structures densely aggregated along a stem. Strobili are often called cones, but some botanists restrict the use of the term cone to the woody seed strobili of conifers. Strobili are characterized by a central axis surrounded by spirally arranged or decussate structures that may be modified leaves or modified stems.

<i>Phlegmariurus phlegmaria</i> Species of fern

Phlegmariurus phlegmaria, synonym Huperzia phlegmaria, commonly known as either coarse tassel fern or common tassel fern, is an epiphytic species native to rainforests in Madagascar, some islands in the Indian Ocean, Asia, Australasia and many Pacific Islands. Phlegmariurus phlegmaria is commonly found in moist forests and rainforests at high altitudes, in and amongst mosses and other epiphytes. Members of the order Lycopodiales are commonly referred to as clubmosses.

<span class="mw-page-title-main">Lepidodendrales</span> Extinct order of vascular tree-like plants

Lepidodendrales or arborescent lycophytes are an extinct order of primitive, vascular, heterosporous, arborescent (tree-like) plants belonging to Lycopodiopsida. Members of Lepidodendrales are the best understood of the fossil lycopsids due to the vast diversity of Lepidodendrales specimens and the diversity in which they were preserved; the extensive distribution of Lepidodendrales specimens as well as their well-preservedness lends paleobotanists exceptionally detailed knowledge of the coal-swamp giants’ reproductive biology, vegetative development, and role in their paleoecosystem. The defining characteristics of the Lepidodendrales are their secondary xylem, extensive periderm development, three-zoned cortex, rootlike appendages known as stigmarian rootlets arranged in a spiralling pattern, and megasporangium each containing a single functional megaspore that germinates inside the sporangium. Many of these different plant organs have been assigned both generic and specific names as relatively few have been found organically attached to each other. Some specimens have been discovered which indicate heights of 40 and even 50 meters and diameters of over 2 meters at the base. The massive trunks of some species branched profusely, producing large crowns of leafy twigs; though some leaves were up to 1 meter long, most were much shorter, and when leaves dropped from branches their conspicuous leaf bases remained on the surface of branches. Strobili could be found at the tips of distal branches or in an area at the top of the main trunk. The underground organs of Lepidodendrales typically consisted of dichotomizing axes bearing helically arranged, lateral appendages serving an equivalent function to roots. Sometimes called "giant club mosses", they are believed to be more closely related to extant quillworts based on xylem, although fossil specimens of extinct Selaginellales from the Late Carboniferous also had secondary xylem.

<i>Dendrolycopodium obscurum</i> Species of spore-bearing plant

Dendrolycopodium obscurum, synonym Lycopodium obscurum, commonly called rare clubmoss, ground pine, or princess pine, is a North American species of clubmoss in the family Lycopodiaceae. It is a close relative of other species such as D. dendroideum and D. hickeyi, also treelike. It is native to the eastern United States and southeastern Canada from Georgia to Minnesota to Nova Scotia. It grows in the understory of temperate coniferous and deciduous forests, where it is involved in seral secondary succession, growing in clonal colonies some years after disturbance has occurred. It has also been found in Japan, Taiwan, Korea, Russian Far East, and northeastern China.

<i>Selaginella uliginosa</i> Species of spikemoss in the family Selaginellaceae

Selaginella uliginosa is a small plant in the spikemoss family Selaginellaceae which is endemic to Australia. An ancient and primitive plant, usually under 10 centimetres tall, it is often seen in sunny moist areas. The specific epithet uliginosa is from Latin, referring to the plant's preference for growing in swampy locations.

<i>Diphasium scariosum</i> Species of spore-bearing plant

Diphasium scariosum, synonym Lycopodium scariosum, commonly known as spreading clubmoss or creeping club moss, is a species in the club moss family Lycopodiaceae. The genus Diphasium is accepted in the Pteridophyte Phylogeny Group classification of 2016, but not in other classifications which submerge the genus in Lycopodium.

<i>Selaginella stellata</i> Species of spore-bearing plant

Selaginella stellata, also recognized by its common name, starry spikemoss or starry spike-moss, is a species of spikemoss of the family Selaginellaceae. It is a type of lycopod that grows naturally in Mexico and Central American countries like Guatemala and Belize and can also be found in the state of Hawaii.

<span class="mw-page-title-main">Lycopodioideae</span> Subfamily of spore-bearing plants

Lycopodioideae is a subfamily in the family Lycopodiaceae in the Pteridophyte Phylogeny Group classification of 2016. It is equivalent to a broad circumscription of the genus Lycopodium in other classifications. Like all lycophytes, members of the Lycopodioideae reproduce by spores. The oldest fossils of modern members of the subfamily date to the Early Cretaceous.

Kowieria is an extinct genus of lycopsid from the Late Devonian from Waterloo Farm, containing the single species Kowieria alveoformis. As of 2021 it is being characterised as incertae sedis. It was first described in 2017 from a black shale layer interbedded with quartzite strata of the Famennian aged Witpoort Formation.

<i>Selaginella ciliaris</i> Species of spore-bearing plant

Selaginella ciliaris is a plant in the family Selaginellaceae which is native to areas from India and Nepal eastwards to China and Taiwan, and south to northern Australia.

References

  1. ↑ "Selaginella apoda". NatureServe Explorer. NatureServe. Retrieved 2008-01-28.
  2. 1 2 In: Flora Brasiliensis 1(2): 119. 1840. [as Selaginella "apus" ] "Name - !Selaginella apoda (L.) Spring". Tropicos. Saint Louis, Missouri: Missouri Botanical Garden . Retrieved March 29, 2010.
  3. ↑ "Name - !Selaginella apoda (L.) Spring synonyms". Tropicos. Saint Louis, Missouri: Missouri Botanical Garden. Retrieved March 29, 2010.
  4. ↑ USDA, NRCS (n.d.). "​Selaginella apoda​". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 11 August 2016.
  5. ↑ Valdespino, Iván A. (1993). "Selaginella apoda". Flora of North America. Vol. 2. Oxford University Press.
  6. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Schulz, Christian; Little, Damon P.; Stevenson, Dennis W.; Bauer, Dennise; Moloney, Ciaran; Stützel, Thomas (September 2010). "An Overview of the Morphology, Anatomy, and Life Cycle of a New Model Species: The Lycophyte (L.) Spring". International Journal of Plant Sciences. 171 (7): 693–712. doi:10.1086/654902. S2CID   83707347.
  7. 1 2 "Selaginella apoda (meadow spikemoss): Go Botany". gobotany.nativeplanttrust.org.
  8. 1 2 Somers, Paul; Buck, William R. (1 January 1975). "Selaginella ludoviciana, S. apoda and Their Hybrids in the Southeastern United States". American Fern Journal. 65 (3): 76–82. doi:10.2307/1546743. JSTOR   1546743.
  9. 1 2 3 4 Buck, William R.; Lucansky, Terry W. (1 January 1976). "An Anatomical and Morphological Comparison of Selaginella apoda and Selaginella ludoviciana". Bulletin of the Torrey Botanical Club. 103 (1): 9–16. doi:10.2307/2484743. JSTOR   2484743.
  10. ↑ Morton, C.V. (1967). "Selaginella apus or apoda?". American Fern Journal. 57 (3): 104–106. doi:10.2307/1546228. JSTOR   1546228.
  11. 1 2 "Lycopodioides apoda (L.) Kuntze — The Plant List". www.theplantlist.org.
  12. 1 2 3 4 Zhou, Xin-Mao; Rothfels, Carl J.; Zhang, Liang; He, Zhao-Rong; Le Péchon, Timothée; He, Hai; Lu, Ngan Thi; Knapp, Ralf; Lorence, David; He, Xing-Jin; Gao, Xin-Fen; Zhang, Li-Bing (August 2016). "A large-scale phylogeny of the lycophyte genus Selaginella (Selaginellaceae: Lycopodiopsida) based on plastid and nuclear loci". Cladistics. 32 (4): 360–389. doi: 10.1111/cla.12136 . PMID   34740298. S2CID   84094538.
  13. 1 2 3 4 Weakley, Alan S. "UNC Herbarium". herbarium.unc.edu.
  14. 1 2 Bowen, John E.; Gauch, Hugh G. (April–June 1965). "The Essentialty of Boron for Dryopteris dentata and Selaginella apoda". American Fern Journal. 55 (2): 67–73. doi:10.2307/1546138. JSTOR   1546138.
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