This is the HTML-version 2.1 of:
Thonner's analytical key to the families of flowering plants.
This book was published in Leiden and Wageningen in 1981
Leiden (Leiden Botanical series vol.5) and
One of the authors, R. Geesink, died in September 1992.
Currently this book is available from:
PO BOX 321
2300 AH Leiden
This publisher is specialised in botanical (taxonomical) literature. Visit his catalogue at http://www.euronet.nl./users/backhuys
There is an official agreement with Backhuys which allows me to
publish this HTML-version on the internet.
Notes on release 2.1
Links for the conifers are updated. The link to Taxodiaceae is changed to the
Family descriptions are visible in full-size window.
The Leguminosae - (sub)families (Caesalipiniaceae,Papilionaceae and Mimosaceae) are available in the 'index of families'
Some synonyms where shown as failing links.
in version 2.0
On a meeting with authors Veldkamp and Ridsdale I received a revision
for key's nr 2005 - 2012, and drawings of flower diagrams.
Since in the book key 225 was deleted, key 584a was inserted and in the
revised part of the key, entry 2013 had to be deleted too,the key is
For easy reference to the original key numbers the old numbers are mentioned in the first lead of the key-entry if appropriate.
All minor families, tribes or even genera that could be linked to families mentioned on the biodiversity-site are linked to this site, without discussion on taxonomical relevance.
The drawings in the book are integrated in the glossary.
In order to accommodate these images a few new entries are added to the glossary (apetalous, choripetalous, sympetalous and amphitropous).
The larger (overview) plates are on demand and overlay key-text window. In order to continue with the key you should click on the Backward-icon of the Browser.
The introductional chapters from Thonner's analytical key are added. Synonyms are present in two tables and third table is added with families present on the biodiversity-site from L. Watson and M. J. Dallwitz but have no reference in this key.
Danny Meirte,Royal Museum Central Africa Tervuren (Belgium), noted a "missing link" to the Didieraceae on the delta-cite. This link is now correct.
Peter Hargreaves found a missing "next" in key-entry 1572a. This
omission is corrected, and checked in the rest of the key. The rewritten
integrity-script thinks the key is okay now.
As at the end of the introduction in Thonner's keys (p. ix)
the authors stated:
We invite the users to point out errors, difficulties and omissions. It should then be indicated in which couplets difficulties arose with a suggestion as to how they might be remedied. A representative specimen would be useful, even if only on loan. Any assistance will be acknowledged in future editions.
Communication should be sent to:
PO BOX 9514
2300 RA Leiden
Internet access and a browser understanding frames and images. (as all
newer releases of Internet Explorer do)
There are no 'ALT' or warnings implemented for browsers that don't
understand FRAMES or IMAGES.
Since the text is a scientific one, no fancy backgrounds or avi's are added.
This is not the book
There are a number of differences between this HTML-version and the
These HTML-pages were generated by:
5272 RK St. Michielsgestel
with permission of authors and publisher
Why this text on Internet ?
As a student in Utrecht I worked at the biological faculty at
the institute of "Bijzondere Plantkunde" (taxonomically botanical
institute) (1977) on a monograph on the saprophytic genus Voyria
(Gentianaceae) with Dr. Paul Maas as supervisor. One of the botanists,
Jan Lindeman, used a punch-card flora for Brazil and Suriname. I was
attended to the punch-card system of B. Hansen and K. Rahn
Determination of Angiosperm families by means of a punched-card
system. During that time I also learned to work with Anleitung zum
Bestimmen der Familien der Blütenpflanzen, from 1917.
I wrote a family-determination program based on this Angiosperm punched-card system. At that time my PC was a P2000-computer whith BASIC as programming language and a bad Z80-assembler and data where stored on a small tape cassette. With some help from some friends the ca 70.000 holes where translated in arrays of 1 and 0, and converted to bits. At last the basic-program worked (16 KB internal memory and 9 KB needed by binary data) performed a minimal task in preventing shuffling the punched cards.
The next computer was a 8086-machine without harddisk, but compilers
where small enough to work from floppy disks. The internal memory was
720 KB, a real arena compared to the p2000. The program was rewritten in
c and worked fine, until the computer (a Tulip system II) destroyed the last floppy with
At this moment I still have the binary data but not a working program.
A few years ago I was very surprised to discover a program based on this punched-card-system at Internet and it is available as windows version 3.0 at http://www.mip.berkeley.edu/meka/meka.html
I am a regular user of floras and don't like the traditional key where you easily get lost but prefer long keys as in e.g. The flora europaea. At one time I decided to rearrange the key in this long format for own use. I started scanning the text, converted the text to straight asci, undaunted by the huge numbers of misspelt words by the OCR-program. The mistakes should all be corrected by now.
Since the text has a good structure it was straightforward to write a script in a language like Perl.
At last the script was ready and the long key format could be typeset with Latex, but the printed key was unreadable.
Last year I tried to convert the key to HTML-format. This turned out to be an interesting task. I wrote a number of Perl scripts to split the file and to generate the html-tables and indexes out of the keys.
After all it took so much time that I decided to ask for an official permission to get this text on the Internet so more people could use these HTML-keys.
Hopefully there will be key-writers and key-hackers to create a public "key to the plant genera" that is useful for people with interest in plant-taxonomy, and scientifically acceptable.
Although I am a pharmacist my personal interest is mainly in computers and
Terminology is most extensively covered by 'Botanical Latin'.
'Flowering plants' is a very good illustrated book with descriptions of flowering plant families. Try one of these books for more technical information.
'The visual dictionary' is beautifully illustrated.
Besides the already mentioned web-sites I will add for this moment
This is a nice website with lots of links to (ethno/eco/taxo) botanical literature and sites of interest.