History of botany scope of the subject as technology has opened up new techniques and areas of study. Modern molecular systematics, for example, entails the principles and techniques of taxonomy, molecular biology, computer science and more. Within botany there are a number of sub-disciplines that focus on particular plant groups, each with their own range of related studies (anatomy, morphology etc.). Included here are: phycology (algae), pteridology (ferns), bryology (mosses and liverworts) and palaeobotany (fossil plants) and their histories are treated elsewhere (see side bar). To this list can be added mycology, the study of fungi, which were once treated as plants, but
Evolutionary history of plants of water and mineral nutrients such as phosphorus, in exchange for organic compounds which they could not synthesize themselves. Such fungi increase the productivity even of simple plants such as liverworts. To photosynthesise, plants must absorb from the atmosphere. However, this comes at a price, since making the tissues available for to enter allows water to evaporate. Water is lost much faster than is absorbed, so plants need to replace it. Early land plants transported water apoplastically, within the porous walls of their cells. Later, they evolved the ability to control water loss (and acquisition) through the use of a