Topic
Lygodium
About: Lygodium is a research topic. Over the lifetime, 89 publications have been published within this topic receiving 1408 citations. The topic is also known as: Hagnaya.
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TL;DR: The ecology of Cainozoic ferns is documented (excluding that based only on nearest living relatives). Free-floating water Ferns (of the modern genera Azolla and Salvinia ) are widespread in the Cainogene as mentioned in this paper.
125 citations
TL;DR: The ecological problems associated with the fern and its naturalization and spread, probable origin, and potential to spread, and the control attempts to date are discussed, including the potential of biological control to reduce populations of this plant and to limit its spread.
Abstract: -Lygodium microphyllum, a native of the warm and wet regions of the Old World, was first detected to be naturalized in southeastern Florida in 1965. This fern has become an aggressive invader of natural vegetation in many different habitats that are frequently dominated by the weed. Aerial surveys conducted in 1993, 1995, and 1997 detected increasing densities and continued expansion of its distribution in Florida. The fern is expected to continue to increase in Florida and could spread by spores to suitable habitats in Texas and Mexico. No effective method of control for the plant exists. Lygodium microphyllum (Cav.) R. Br. (Schizaeaceae), or Old World climbing fern, is native to wet tropical and subtropical regions of the Old World. It has become a serious weed in southeastern Florida, where it is increasing in density and range. In the present paper we discuss the ecological problems associated with the fern and its naturalization and spread, probable origin, and potential to spread, and the control attempts to date. The companion paper (Pemberton, 1998) discusses the potential of biological control to reduce populations of this plant and to limit its spread. The fern's native distribution and taxonomic relations, both essential information for a biological control program, are also reported.
117 citations
TL;DR: The mixed mating system observed in L. microphyllum appears to give this species the ability to invade distant habitats and then adapt to local conditions, which has likely facilitated their ability to colonize and spread through Florida.
Abstract: The effect of culture system and population source on sexual expression and sporophyte production was examined for two invasive fern species in Florida, USA, Lygodium microphyllumand L. japonicum (Schizaeaceae). Both species are currently spreading through Florida. Long-distance dispersal of ferns is thought to rely on successful intragametophytic selfing. Given the rate of spread observed in both Lygodium species, we hypothesized that both species are capable of intragametophytic selfing. To test this hypothesis, gametophytes of both species were grown in vitro as isolates, pairs, and groups. Both species were capable of intragametophytic selfing; 78% of L. microphyllum isolates produced sporophytes and over 90% of the L. japonicum isolates produced sporophytes. Lygodium microphyllum also displayed the ability to reproduce via intergametophytic crossing, facilitated by an antheridiogen pheromone. Sporophyte production was rapid across mating systems for both species, an advantage in Florida’s wet and dry seasonal cycles. The high intragametophytic selfing rate achieved by both species has likely facilitated their ability to colonize and spread through Florida. The mixed mating system observed in L. microphyllum appears to give this species the ability to invade distant habitats and then adapt to local conditions.
85 citations
TL;DR: Placement of Psilotum in a class of its own receives no support from the mitochondrial sequences, which rather suggest its inclusion among eusporangiate ferns (Ophioglossales).
Abstract: A conserved coding region of the mitochondrial nad5 gene (1098–1107 bp of protein coding sequence) was amplified from 30 pteridophytes (26 ferns and 4 fern allies). A group II intron sequence conserved in all ferns except the eu-sporangiate genus Ophioglossum is also present in the whisk fern Psilotum nudum and the lycopod Huperzia selogo, but absent from the horsetails (Equisetum), the seed plants and the bryo-phytes. Phylogenetic trees constructed with different methods consistently suggest several monophyletic units. The conserved group II intron sequence provides valuable additional phylogenetic information. Leptosporangiate ferns are monophyletic with Osmunda as the basal-most branching genus followed by Trichomanes, Matonia and Lygodium. These genera are set distantly apart from other leptosporangiate ferns, including the tree and water ferns, which branch in close proximity. Species of Polypodiaceae, Dryopteridaceae, Thelypteridaceae, Aspleniaceae and Blechnaceae appear in a monophyletic crown group of derived leptosporangiate ferns with Dryopteridaceae as a paraphyletic taxon. Placement of Psilotum in a class of its own receives no support from the mitochondrial sequences, which rather suggest its inclusion among eusporangiate ferns (Ophioglossales). RNA editing is required to correct the genetic information of the nad5 gene in all species investigated and includes the removal of stop codons from the reading frames. The influence of RNA editing on phylogenetic tree construction is investigated and discussed.
72 citations
TL;DR: The eriophyid mite F. perrepae shows the greatest potential for biological control based on field surveys and initial laboratory observations; however, future studies must identify mite genotypes that are best adapted to the invasive Florida form of the fern.
71 citations