ID Visualisation

Punched-card grasses key

In 1985 the Field Studies Council published an innovative polyclave (multi-access) key to British grasses that relied on cards with holes punched in them. The key was the work of Richard J. Pankhurst - a true early innovator of using computers for biological identification - and Judith M. Allinson an experienced botanist working for the FSC.

As a bit of fun and a tribute to the pioneering work of Pankhurst, Allinson and the FSC, we here present a multi-access key based on the original. But instead of encoding the knowledge-base on punched-cards, it is encoded in a spreadsheet. And instead of stacking cards and peering through holes, the ID Framework provides a user interface! We've kept pretty much everything else, including the taxonomy and the character help, as it was in the original.

The key uses vegetative (i.e. non-flowering) characters only. There was one card for every state of 49 characters. In all there were 124 character states and therefore 124 cards. On every card there were 92 identical numbered positions representing 92 taxa. If a taxon could have the character state represented by a card, a hole was punched in the position corresponding to that taxon.

To use the key, you selected cards representing the character states of your specimen and rejected the rest. If you could see all the way through any of the holes representing the taxa when you stacked the selected cards up, then those taxa were possible matches for your specimen, because they matched all the selected character states.

Although the key used punched cards of the type used in the 1980s (and before) to encode and run computer programs, they were not used in this way for this key - it isn't a computer program. However the principles, as Pankhurst and Allinson knew, were amenable to the construction of a codified computer program.

For this Framework implementation, instead of using morphological groupings for the characters we stuck with the 'pink', 'blue' and 'white' groupings used in the original key. The authors described these character groupings thus:

  • Pink cards will be the easiest to use
  • Blue ones are more difficult, or less useful
  • White ones should only be used as a last resort

To use this ID Framework implementation of the punched-card key, click your mouse where it says 'select option' underneath the character you are interested in and select the option which matches your specimen. Hold the mouse pointer over the character name to see the help. The list of taxa is re-ordered to match your input with the best matches towards the top and the worst matches towards the bottom.