Claim: Tasmania's diversity of vascular plants (land plants that have lignified tissues) can be attributed to Tasmania's isolation from the mainland during the interglacial periods.
Evidence: During long periods geographically and genetically isolated, it is known for its unique flora and fauna. Vascular plants (from Latin vasculum: duct), also known as Tracheophyta (/trækiːˈɒfɪtə, -oʊfaɪtə/) (the tracheophytes /trəˈkiːəfaɪts/, from the Greek trācheia), form a large group of plants (c. 300,000 accepted known species) that are defined as land plants that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. The terrain includes a variety of reefs, atolls, many small islands, and a variety of topographical and edaphic regions on the largest island, all of which promote the development of unusually concentrated biodiversity.