Fern fern ("Onoclea sensibilis"). Giant water fern ("Salvinia molesta") is one of the world's worst aquatic weeds. The important fossil fuel coal consists of the remains of primitive plants, including ferns. Ferns have been studied and found to be useful in the removal of heavy metals, especially arsenic, from the soil. Other ferns with some economic significance include: The study of ferns and other pteridophytes is called pteridology. A pteridologist is a specialist in the study of pteridophytes in a broader sense that includes the more distantly related lycophytes. Pteridomania is a term for the Victorian era craze of fern collecting
Pitcher Plants of the Old World field work that it involved: I prepared "Pitcher Plants of the Old World" in response to the lack of available information on dozens of species of "Nepenthes". Since many species of "Nepenthes" are not in cultivation, and also because there is often confusion concerning those that are, I resolved to study and photograph each species of "Nepenthes" and "Cephalotus" in the wild, in order to document each adequately. After graduating from university in 2006 at the age of 23, I began three years of intense research focusing on "Nepenthes" and "Cephalotus", and spent a cumulative total of eighteen months in