35-428: See text The Lycopodiaceae (class Lycopodiopsida , order Lycopodiales) 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
70-595: A modified shoot system acting as roots, bipolar and secondary growth , and an upright stance. The remains of Lepidodendron lycopods formed many fossil coal deposits. In Fossil Grove , Victoria Park, Glasgow, Scotland, fossilized lycophytes can be found in sandstone . The Lycopodiopsida had their maximum diversity in the Pennsylvanian (Upper Carboniferous), particularly tree-like Lepidodendron and Sigillaria that dominated tropical wetlands. The complex ecology of these tropical rainforests collapsed during
105-527: A more broadly defined taxon of lycophytes that includes some extinct groups more distantly related to extant lycophytes, such as the zosterophylls . For example, Kenrick & Crane (1997) use the subdivision Lycophytina for this purpose, with all extant lycophytes falling within the class Lycopsida. Other sources exclude the zosterophylls from any "lycophyte" taxon. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I),
140-401: A strobilus (plural: strobili), which resembles a tiny battle club , from which the common name derives. Members of the family share the common feature of having a microphyll , which is a "small leaf with a single vein, and not associated with a leaf gap in the central vascular system." In Lycopodiaceae, the microphylls often densely cover the stem in a linear, scale-like, or appressed fashion to
175-606: Is an endophytic fungus present in Huperzia serrata that produces Huperzine A , a biomedical compound which has been approved as a drug in China and a dietary supplement in the U.S. to treat Alzheimer's Disease. This fungal endophyte can be cultivated much more easily and on a much larger scale than H. serrata itself which could increase the availability of Huperzine A as a medicine. The spores of lycopods are highly flammable and so have been used in fireworks . Lycopodium powder ,
210-553: Is common, whereas polyplastidic meiosis is found in Lycopodielloideae and Huperzioideae. The family Lycopodiaceae is considered to be basal within the Lycopodiopsida (lycophytes). One hypothesis for the evolutionary relationships involved is shown in the cladogram below. Lycopodiaceae Isoetaceae Selaginellaceae Within the family, there is support for three subgroups. In 2016, Field et al. proposed that
245-472: Is completely absent in seed plants except for Ginkgo and cycads). Because only two flagella puts a size limit on the genome, we find the largest known genomes in the clade in Isoetes , as multiflagellated sperm is not exposed for the same selection pressure as biflagellate sperm in regard of size. The extant lycophytes are vascular plants (tracheophytes) with microphyllous leaves , distinguishing them from
280-658: Is developed enough for independence is the new plant dropped to the ground. Many club-moss gametophytes are mycoheterotrophic and long-lived, residing underground for several years before emerging from the ground and progressing to the sporophyte stage. Lycopodiaceae and spikemosses ( Selaginella ) are the only vascular plants with biflagellate sperm, an ancestral trait in land plants otherwise only seen in bryophytes . The only exceptions are Isoetes and Phylloglossum , which independently has evolved multiflagellated sperm cells with approximately 20 flagella (sperm flagella in other vascular plants can count at least thousand, but
315-771: The Induan (earliest Triassic), particularly Pleuromeia . After the worldwide Permian–Triassic extinction event , members of this group pioneered the repopulation of habitats as opportunistic plants. The heterogeneity of the terrestrial plant communities increased markedly during the Middle Triassic when plant groups like horsetails, ferns, pteridosperms , cycads , ginkgos and conifers resurfaced and diversified quickly. Lycophytes form associations with microbes such as fungi and bacteria, including arbuscular mycorrhizal and endophytic associations. Arbuscular mycorrhizal associations have been characterized in all stages of
350-512: The Pteridophyte Phylogeny Group (PPG I), which places them all in the class Lycopodiopsida, which includes the classes Isoetopsida and Selaginellopsida used in other systems. (See Table 2 .) Alternative classification systems have used ranks from division (phylum) to subclass. In the PPG ;I system, the class is divided into three orders, Lycopodiales , Isoetales and Selaginellales . Club-mosses (Lycopodiales) are homosporous, but
385-537: The euphyllophytes (plants with megaphyllous leaves ). The sister group of the extant lycophytes and their closest extinct relatives are generally believed to be the zosterophylls , a paraphyletic or plesion group. Ignoring some smaller extinct taxa, the evolutionary relationships are as shown below. (multiple branches, incertae sedis ) living lycophytes and their extinct close relatives ferns & horsetails spermatophytes (seed plants) As of 2019 , there
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#1732787679774420-470: The Early Cretaceous of China. Lycopodiopsida See Table 1 . 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
455-687: The Lycopodiopsida first appear in the Silurian period, along with a number of other vascular plants. The Silurian Baragwanathia longifolia is one of the earliest identifiable species. Lycopodolica is another Silurian genus which appears to be an early member of this group. The group evolved roots independently from the rest of the vascular plants. From the Devonian onwards, some species grew large and tree-like. Devonian fossil lycopsids from Svalbard , growing in equatorial regions, raise
490-679: The Middle Pennsylvanian due to a change in climate. In Euramerica , tree-like species apparently became extinct in the Late Pennsylvanian, as a result of a transition to a much drier climate, giving way to conifers , ferns and horsetails . In Cathaysia (now South China), tree-like species survived into the Permian . Nevertheless, lycopodiopsids are rare in the Lopingian (latest Permian), but regained dominance in
525-473: The PPG I system, the family has 16 accepted genera, grouped into three subfamilies, Lycopodielloideae, Lycopodioideae and Huperzioideae, based in part on molecular phylogenetic studies. The Huperzioideae differ in producing spores in small lateral structures in the leaf axils, and it has been suggested that they be recognized as a separate family. Other sources use fewer genera; for example, the three genera placed in
560-427: The branch leading to Selaginella and Isoetes (heterosporous lycophytes) about ~400 million years ago, during the early Devonian. The two subfamilies Lycopodioideae and Huperzioideae diverged ~350 million years ago, but has evolved so slowly that about 30% of their genes are still in syntenic blocks (remaining in the same arrangement). They have also gone through independent whole genome duplications . In most plants
595-466: The dried spores of the common clubmoss, was used in Victorian theater to produce flame-effects. A blown cloud of spores burned rapidly and brightly, but with little heat. (It was considered safe by the standards of the time.) Palhinhaea See text . Palhinhaea is a genus of lycophytes in the family Lycopodiaceae . In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), it
630-408: The extant lycophytes (and their closest extinct relatives) varies widely. Table 1 below shows some of the highest ranks that have been used. Systems may use taxa at a rank lower than the highest given in the table with the same circumscription; for example, a system that uses Lycopodiophyta as the highest ranked taxon may place all of its members in a single subclass. Some systems use a higher rank for
665-534: The extant lycophytes as shown below. Some extinct groups, such as zosterophylls , fall outside the limits of the taxon as defined by the classifications in Table 1 above. However, other extinct groups fall within some circumscriptions of this taxon. Taylor et al. (2009) and Mauseth (2014) include a number of extinct orders in their division (phylum) Lycophyta, although they differ on the placement of some genera. The orders included by Taylor et al. are: Mauseth uses
700-1338: The following genera as members of Lycopodiaceae. All of these are recognized by the Pteridophyte Phylogeny Group classification of 2016 (PPG I), except for the genus Brownseya , described in 2021. Other classifications circumscribe the genera in the family more broadly, recognizing the subfamilies Lycopodielloideae, Lycopodioideae, and Huperzioideae as the genera Lycopodiella , Lycopodium , and Huperzia . Phylogeny of Lycopodiaceae Huperzia s.s. Bernhardi Phylloglossum Kunze Phlegmariurus (Herter) Holub Brownseya Zhang et al. Palhinhaea Franco & Vasconcellos Lateristachys Holub Pseudolycopodiella Holub Lycopodiella Holub Lycopodiastrum Holub ex Dixit Diphasiastrum Holub Lycopodium s.s. von Linné Spinulum Haines Pseudolycopodium Preslia ex Holub Pseudodiphasium Holub Austrolycopodium Holub Dendrolycopodium Haines Diphasium Presl ex Rothmaler The members of Lycopodiaceae are terrestrial or epiphytic in habit and are most prevalent in tropical mountain and alpine environments. Though Lycopodiaceae are most abundant in these regions, they are cosmopolitan, excluding arid environments. Lycopodiaceae (homosporous lycophytes) split off from
735-411: The genera Selaginella (spikemosses) and Isoetes (quillworts) are heterosporous, with female spores larger than the male. As a result of fertilisation, the female gametophyte produces sporophytes. A few species of Selaginella such as S. apoda and S. rupestris are also viviparous ; the gametophyte develops on the mother plant, and only when the sporophyte's primary shoot and root
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#1732787679774770-683: The lycophyte lifecycle: mycoheterotrophic gametophyte, photosynthetic surface-dwelling gametophyte, young sporophyte, and mature sporophyte. Arbuscular mycorrhizae have been found in Selaginella spp. roots and vesicles. During the mycoheterotrophic gametophyte lifecycle stage, lycophytes gain all of their carbon from subterranean glomalean fungi. In other plant taxa, glomalean networks transfer carbon from neighboring plants to mycoheterotrophic gametophytes. Something similar could be occurring in Huperzia hypogeae gametophytes which associate with
805-507: The majority of duplicate genes are lost relatively quickly through diploidization , but in this group both sets of genes tends to be retained with relatively few alterations, even after hundreds of millions of years after the duplication event. Spores indicate that the crown group of Lycopodiaceae had emerged by the Triassic-Jurassic boundary, around 200 million years ago, with a member of the crown group of Lycopodioideae known from
840-749: The order †Asteroxylales, placing Baragwanathia in the Protolepidodendrales. The relationship between some of these extinct groups and the extant ones was investigated by Kenrick and Crane in 1997. When the genera they used are assigned to orders, their suggested relationship is: †Drepanophycales († Asteroxylon , † Baragwanathia , † Drepanophycus ) Lycopodiales †Protolepidodendrales († Leclercqia , † Minarodendron ) Selaginellales ( Selaginella , including subg. Stachygynandrum and subg. Tetragonostachys ) Isoetales ( Isoetes ) †Lepidodendrales († Paralycopodites ) The Lycopodiopsida are distinguished from other vascular plants by
875-430: The plant grew, leaving only a small cluster of leaves at the top. The lycopsids had distinctive features such as Lepidodendron lycophytes, which were marked with diamond-shaped scars where they once had leaves. Quillworts (order Isoetales) and Selaginella are considered their closest extant relatives and share some unusual features with these fossil lycopods, including the development of both bark, cambium and wood ,
910-489: The possession of microphylls and by their sporangia, which are lateral as opposed to terminal and which open (dehisce) transversely rather than longitudinally. In some groups, the sporangia are borne on sporophylls that are clustered into strobili. Phylogenetic analysis shows the group branching off at the base of the evolution of vascular plants and they have a long evolutionary history. Fossils are abundant worldwide, especially in coal deposits . Fossils that can be ascribed to
945-517: The possibility that they drew down enough carbon dioxide to change the Earth's climate significantly. During the Carboniferous , tree-like plants (such as Lepidodendron , Sigillaria , and other extinct genera of the order Lepidodendrales ) formed huge forests that dominated the landscape. Unlike modern trees, leaves grew out of the entire surface of the trunk and branches, but fell off as
980-601: The primary division is between Lycopodielloideae plus Lycopodioideae and the Huperzioideae (names sensu PPG I). Lycopodielloideae ( Lycopodiella s.l.) Lycopodioideae ( Lycopodium s.l.) Huperzioideae ( Huperzia s.l.) There are about 400 known species in the family Lycopodiaceae. Sources differ in how they group these into genera. Field et al. (2016) say "Most Lycopodiaceae species have been re-classified into different genera several times, leading to uncertainty about their most appropriate generic identification." In
1015-409: The resemblance of either the roots or branch tips to a wolf's paw. Members of Lycopodiaceae are not spermatophytes and so do not produce seeds . Instead they produce spores , which are oily and flammable, and are the most economically important aspects of these plants. The spores are of one size (i.e. the plants are isosporous ) and are borne on a specialized structure at the apex of a shoot called
1050-552: The same glomalean phenotypes as nearby Huperzia hypogeae sporophytes. Fungal endophytes have been found in many species of lycophyte, however the function of these endophytes in host plant biology is not known. Endophytes of other plant taxa perform roles such as improving plant competitive fitness, conferring biotic and abiotic stress tolerance, promoting plant growth through phytohormone production or production of limiting nutrients. However, some endophytic fungi in lycophytes do produce medically relevant compounds. Shiraia sp Slf14
1085-422: 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. The nomenclature and classification of plants with microphylls varies substantially among authors. A consensus classification for extant (living) species was produced in 2016 by
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1120-451: The stem, and the leaves are either opposite or spirally arranged. The club mosses commonly grow to be 5–20 cm tall. The gametophytes in most species are non-photosynthetic and myco-heterotrophic , but the subfamily Lycopodielloideae and a few species in the subfamily Huperzioideae have gametophytes with an upper green and photosynthetic part, and a colorless lower part in contact with fungal hyphae. In Lycopodioideae monoplastidic meiosis
1155-578: The subfamily Huperzioideae in PPG I, Huperzia , Phlegmariurus and Phylloglossum , have also all been treated within a broadly defined Huperzia . The species within this family generally have chromosome counts of n =34. A notable exception are the species in Diphasiastrum , which have counts of n =23. As of June 2024, the Checklist of Ferns and Lycophytes of the World recognized
1190-455: The three orders are placed in a single class, Lycopodiopsida, holding all extant lycophyte species. Older systems have used either three classes, one for each order, or two classes, recognizing the closer relationship between Isoetales and Selaginellales. In these cases, a higher ranked taxon is needed to contain the classes (see Table 1). As Table 2 shows, the names "Lycopodiopsida" and "Isoetopsida" are both ambiguous. The PPG I system divides up
1225-401: Was broad agreement, supported by both molecular and morphological evidence, that the extant lycophytes fell into three groups, treated as orders in PPG I, and that these, both together and individually, are monophyletic , being related as shown in the cladogram below: lycopodiales Isoetales Selaginellales The rank and name used for the taxon holding
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