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 in place of flowers. Thus, sometime in history, the developmental program leading to formation of a leaf must have been altered to generate a flower. There probably also exists an overall robust framework within which the floral diversity has been generated. An example of that is a gene called "LEAFY (LFY)", which is involved in flower development in "Arabidopsis thaliana". The homologs of this gene are found in angiosperms as diverse as tomato, snapdragon, pea, maize and even gymnosperms. Expression of "Arabidopsis thaliana" LFY in distant plants like poplar and citrus also results in flower-production in these plants. The "LFY"