||Dr. Ilia J. Leitch, Prof. Andrew R. Leitch, Genome Size Diversity and Evolution in Land Plants, Plant Genome Diversity Volume 2, 2013, pp 307-322 p.314 left column top paragraph
||Paton AJ, Brummitt N, Govaerts R, Harman K, Hinchcliffe S, Allkin B, Lughadha EN (2008) Towards target 1 of the global strategy for plant conservation: a working list of all known plant species – progress and prospects. Taxon 57: 602–611
||"Seed plants are estimated to comprise c. 96% of extant
vascular plant diversity and are divided into gymnosperms
(comprising c. 850 species) and angiosperms with an
estimated 352,000 species (primary source)."