Biodiversity is threatened by humankind’s continuing usurpation of our planet’s physical space and resources, and the associated damage to the landscape and atmosphere. Food production is widely acknowledged to be the most important human activity that needs to be addressed in order to mitigate the current biodiversity and environmental crises. In this contribution we feature obscure plants cal...

Evidence of fossil Peronosporomycetes has been slow to accumulate. In this review various fossils historically assigmed to the Peronosporomycets are dicussed briefly and an explanation is provided as to why the fossil record of this grouop has remained inconsistent. In recent year there has been several new reports of fossil peronosporomycetes based on structurally preserved oogonium-antheridiu...

RFID applications create a need for low-cost security and privacy in potentially hostile environments. Our measurements show that initialization of SRAM produces a physical fingerprint. We propose a system of Fingerprint Extraction and Random Numbers in SRAM (FERNS) that harvests static identity and randomness from existing volatile CMOS storage. The identity results from manufacture-time physi...

Homosporous vascular plants are typically depicted as extreme inbreeders, with bisexual gametophytes that produce strictly homozygous sporophytes. This view is promulgated in textbook life cycles despite ample evidence that natural populations of most species regularly outcross. We review research on a variety of mechanisms, including genetic load, asynchronous production of eggs and sperm, and...

Spores of the aquatic heterosporous fern family Marsileaceae differ markedly from spores of Salviniaceae, the only other family of heterosporous ferns and sister group to Marsileaceae, and from spores of all homosporous ferns. The marsileaceous outer spore wall (perine) is modified above the aperture into a structure, the acrolamella, and the perine and acrolamella are further modified into a r...

In this contribution, we describe latest Cretaceous aquatic plant communities from the La Colonia Formation, Patagonia, Argentina, based on their taxonomic components and paleoecological attributes. The La Colonia Formation is a geological unit deposited during a Maastrichtian-Danian transgressive episode of the South Atlantic Ocean. This event resulted in the deposition of a series of fine-gra...

The chloroplast gene trnK and its associated group II intron appear to be absent in a large and ancient clade that includes nearly 90% of fern species. However, the maturase protein encoded within the intron (matK) is still present and located on the boundary of a large-scale inversion. We surveyed the chloroplast genome sequence of clade-member Adiantum capillus-veneris for evidence of a still...

Brake fern, Pteris vittata, not only tolerates arsenic but also hyperaccumulates it in the frond. The hypothesis that arsenic hyperaccumulation in this fern could function as a defense against insect herbivory was tested. Fronds from control and arsenic-treated ferns were presented to nymphs of the grasshopper Schistocerca americana. Feeding damage was recorded by visual observation and quantif...

The mangrove fern genus Acrostichum grows in the extremely unstable marine intertidal zone under harsh conditions, such as high salt concentrations, tidal rhythms and long-term climate changes. To explore the phylogenetic relationships and molecular mechanisms underlying adaptations in this genus, we sequenced the transcriptomes of two species of Acrostichum, A. aureum and A. speciosum, as well...

UNLABELLED • PREMISE OF THE STUDY Understanding fern (monilophyte) phylogeny and its evolutionary timescale is critical for broad investigations of the evolution of land plants, and for providing the point of comparison necessary for studying the evolution of the fern sister group, seed plants. Molecular phylogenetic investigations have revolutionized our understanding of fern phylogeny, howe...