A summary is presented of the most important ways in which ferns have been important to humanity. Many of these categories are positive such as the use of ferns for subsistence. On the negative side is their role as weeds and as bearers of substances harmful to human health. Many of the traditional uses such as for medicines have been transferred to modern life as societies have modernized. Some uses have even become important in industrial society, for example in the assay of new medicines.
The chromosome number and ploidy level of Cystopteris fragilis (L.) Bernh. are documented for the first time from Iran. The count was tetraploid, with 2n= 4x= 168. This agrees with previous reports of tetraploid C. fragilis from Europe, Asia and the United States.
The Dutch rush: history and myth of the Equisetum trade
In England in the early 19th century at least two products went by the commercial name Dutch Rush, viz. the Rough Horsetail Equisetum hyemale L. used in cabinet making and similar crafts, and the Common Club-rush/Bulrush Schoenoplectus lacustris (L.) Palla used in matting and chair manufacturing. Some authors did not heed the scientific names and confused the properties and geo-cultural backgrounds of both products. Thus the myth took hold that E. hyemale was in culture in the Netherlands and that is was deliberately planted and cared for to protect that country from the sea. Scarce but widespread evidence of trade reveals that this species was economically insignificant. The idea that it owes its common name to imports from Holland could be correct; however, other parts of North and Central Europe, especially the upper Rhine Valley, are more likely to be the original sources from where the Dutch obtained the plants. North America can be reasoned to be an alternative origin, but evidence for this hypothesis is still lacking.
Plagiogyria minuta is distinct from P. egenolfioides var. egenolfioides