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
General of the branch influence, with the all-encompassing rank of general. Full generals (4 star; NATO OF-9) in the Finnish military were classified as generals of infantry ("jalkaväenkenraali"), cavalry ("ratsuväenkenraali"), jaeger ("jääkärikenraali") and artillery ("tykistönkenraali"). The title is now merely honorific, and only one 4-star general is active at any one time in the modern Finnish military. In the German "Wehrmacht" a general of a branch () was linked to service arms of the "Heer" (army) and "Luftwaffe" (air force), depending on where the officer served and what troops he (nominally) commanded. It was equivalent to the three-star ranks of admiral in the Nazi