Globally, it is estimated that there are more than 230,000 varieties of flowering plants. Since the first plants appeared on Earth around 4 billion years ago, they have continued to evolve and diversify to this day. Plant diversity is the result of adaptation to different environments such as water, light, and soil, as well as biological interactions including symbiosis, parasitism, and predation of other plants, fungi, and animals. To understand plant diversity, studies using living plant materials are required.
The Tsukuba Botanical Garden conserves about 7,000 species of living plants - mainly ferns and flowering plants - and conducts studies on biodiversity based on morphological, molecular, cytological, and chemical data.