History of WorldPlants Project: How Many Species Out There?

1989: first PC's were available to "normal" persons. 
No online or computer version of Kew index, European checklist etc. was available

Idea (together with Joachim Rheinheimer / Beetles): how to get databases onto our computers?
It was way too early (no digital pictures, Kew Index and ZooRec were "printed only" and very cumbersome to use with many supplements)

Joachim Rheinheimer started to work on a Curculionidae worldwide database (60.000 species)

Ca. 1994: First version of Kew Index appears on CD-ROM, contains "names only", no synonymy, no distribution

Project idea: Take those data, sort them worldwide and cross-check against local floras and checklists

If I had known 1994 the monumental size of the task, I would have never started...

The Phases of the Project

Phase 1: Get all Kew Index names in files, organize them in a proper format

              Completed from 1994 - 1997

              1 million names, initially ca. 500.000 species listed as valid

              Index Filicum was not available electronically, needed to be re-typed manually (which by the way was the reason that World Ferns started as a separate project and dataset)

Phase 2: Incorporate available country and regional checklists including synonyms

              Biggest task of the entire project, needed 13 years

              Completed from 1997 - 2010 (additions still added...)

              Reduces number of valid species to about 380.000

Phase 3: Incorporate major published floras, where no detailed checklist was available

              Mostly completed from 1997 - 2012, regular additions ongoing

              Reduces number of valid species to about 350.000

              Distribution record complete for 90% of countries

Phase 4: Publish databases for Ferns and Orchids on own website (Karlsruhe University)

              Completed 2004 (with Bernd Schmitt as technical support), ongoing since with regular updates

              -> Other groups not yet covered (system insufficient for large groups)

Phase 5: Establish export procedure to Catalogue of Life

              Completed ca. 2013, since then regular exports into COfL

              Ca. 150.000 species curated = 45 % of total

Phase 6: Cross-check against IPNI files and standardize

              IPNI has much more information vs. Kew Index (publication year!)

              Completed 2010 - 2014 (COfL part, 150.000 species), 2014 - August 2016 (non-COfL part)

              Standardize abbreviations of authors (completed 2019-2020)

              Standardize distribution data and enable automatic data analysis (completed 2019-2020)

Phase 7: Establish new online format for World Plants

              Completed August 2020 (current website)

Phase 8 (ongoing): Refine taxonomic tree, establish sequence according to true relationship

              Use Kubitzki (90% published), APG etc.

              Use phylogenetic "DNA-Articles" - currently a multitude of publications

              Ongoing since inception of database, currently almost complete, additions ongoing

What is missing?

Phase 9: Cross-check against genus revisions and single taxonomic papers

              - Impossible to complete by one person in a lifetime (too much work)

              - Access to online publications not available (no academic sponsor or access)

              - During working hours in regular job a major library is not accessible for me

Phase 10: Standardize literature citations

              - Perhaps through database

              - Currently not achievable, should be standardized using databases

Phase 11: Add pictures for all groups

              - Not achievable for one person

              - Crowdsourcing is problematic (correct ID?)

Current status:

ca. 350.000 species listed as valid (16.9.2020), of them about 10.000 microspecies

ca. 4.000 names remaining as "provisionally accepted" - about 50% of them will possibly survive as valid species

500 - 1.000 species described each year and published in IPNI (trend seems to decline!)

Therefore ca. 345.000 is the correct number of described living plant species as of today, with about 500 - 1000 added each year

About +/- 20.000 tolerance exists based on differing concepts (lumping vs. splitting).

Included: about 10.000 microspecies in few apomictic genera (Ranunculus auricomus agg. - 1000, Rubus fruticosus agg. - 1000, Hieracium and Pilosella - 5000, Taraxacum officinale agg. - 2000, Alchemilla - ca. 500)

Lugadha et al. (2016) arrive through "extrapolation" at 390.000: clearly much too high and nowhere within our checklist-based numbers

The number of real plant species "out there" including the undescribed ones will probably not exceed 400.000 by much