How many plant species are there?

Back when Linnaeus and the boys decided to name all the world's organisms, the task seemed large, but not insurmountable. Little did they know what the tropics had in store for them. Several problems confound trying to answer the question of how many plant species there are. 1. Botanists keep finding new ones, so the discovery of species continues. 2. It's really hard to know if you have a new species because without a digital database (which is under construction) you cannot check all the herbaria for specimens, and this means many species have been named multiple times. 3. As more and more of the Earth's surface is disturbed and destroyed by human activities, we face the fact that many organisms will become extinct before they are known to science. 4. The botanists who do this kind of research are getting rarer as universities seek to hire new faculty doing the latest, newest, most fundable type of research, and taxonomic research, long devalued and denigrated by people doing the latest, newest type of research, gets left to non-academic institutions like museums and botanical gardens, so few students see or come into contact with this type of science, so the problem is getting compounded. The first attempt to solve the second problem was to publish a list of all the new plant species names producing the Index Kewensis, an effort started by a monetary bequest from Charles Darwin! Using existing databases, taxonomic experts have been attempting to purge the lists of alternative names and determine the 1st published official species name. So far the results indicate 301,000 plant species exist after purging 480,000 alternative names called synonyms, but there are still 240,000 names left to assess, so if the same percentage holds true, then the total number of officially named plant species will be pretty close to 400,000. Not bad, not bad. This totally overwhelmes the diversity of other plant groups: only 1000 species of gymnosperms, 15,000 species of pteridosperms, and 23,000 species of mosses & liverworts. It's good we can figure this out before this type of botanist becomes extinct.