Manuscript electronical Premise of research. Ferns (monilophytes) and lycophytes are unique among land plants in having two independent life stages: the gametophyte generation, which is generally small, cordiform, and short-lived, senescing after fertilization, and the sporophyte generation, which is considered the dominant, long-lived portion of the life cycle produced following fertilization....

The genus Emmenomma is revised and now includes three species from Southern Chile, Argentina and Falkland Islands (Islas Malvinas). The type species Emmenomma oculatum is redescribed and considered a senior synonym of E. beauchenicum. Emmenomma oculatum obscurum is removed from synonymy with E. oculatum, raised to the species level and redescribed; the male of this species remains unknown. A ne...

The cyanobacterial symbionts in the fern Azolla have generally been ascribed to either the Anabaena or Nostoc genera. By using comparisons of the sequences of the phycocyanin intergenic spacer and a fragment of the 16S rRNA, we found that the cyanobiont from an Azolla belongs to neither of these genera.

The ferns comprise one of the most ancient tracheophytic plant lineages, and occupy habitats ranging from tundra to deserts and the equatorial tropics. Like their nearest relatives the conifers, modern ferns possess tracheid-based xylem but the structure-function relationships of fern xylem are poorly understood. Here, we sampled the fronds (megaphylls) of 16 species across the fern phylogeny, ...

Angiosperms evolved and diversified during the Cretaceous period. Early angiosperms were short-stature weedy plants thought to have increased fire frequency and mortality in gymnosperm forest, aiding their own expansion. However, no explorations have considered whether the range of novel fuel types that diversified throughout the Cretaceous also altered fire behaviour, which should link more st...

Remarkable diversity in recognized endemic centres as well as noteworthy disjunct distributions have led students of the pteridophytes to seek historical explanations for these phenomena. A suite of distinctive attributes limit the array of possible explanations: most biogeographically significant are ( I ) the smaller number of species-range determinants, and (2) the substantial capacity for l...

PROBLEM BEING ADDRESSED Traditional continuing medical education (CME) approaches do not work well in changing physicians' behaviour, but some promising strategies and technologies might help. Our program sought to meld small-group learning with an Internet e-mail approach. OBJECTIVE OF PROGRAM In 1994, the Family medicine Education and Research Network (FERN) was developed to support on-line...

BACKGROUND Although ferns are often known under collective names in Norway, e.g. blom, a substantial number of vernacular names for individual fern species are known, in particular for useful or poisonous taxa. In the past, the rhizomes (Norwegian: moldfôr) of selected species were collected for fodder. Only scattered records of such use are available from southern Norway, and the tradition's c...