ID keys

The BLS is developing a suite of keys that can be run on PCs and tablets, using LUCID software. If you don't want to install LUCID you can also run them in html format, which requires no installatiion.

The first key, still being tested, is for Cladonia and this can be downloaded from a dropbox folder by clicking on this link . There is no need to install Dropbox, just click on the link and the select each file that you want and take the download option to save it to your own computer.


Installing and running Lucid keys

Lucid keys can be installed on Windows, Mac, Linux and Solar operating systems. The following instructions are for Windows systems. The installation may look quite complicated but is in fact straightforward.

Each Lucid key is distributed with a number of files.

  • 1 – Read Me Before You Start a file giving blow by blow details of how to install a Lucid key.
  • 2 – How to Use a Lucid Key a file giving details of how best to us a key to identify an unknown.
  • Folder containing the key and named accordingly, e.g. ‘Cladonia of the British Isles, V.4, December 2015’.
  • A folder called ‘Lucid 3 Player’ which includes a copy of the Lucid software needed to run the key.
  • A file sharing the same name as the key but with a file extension of ‘.lck4’.
  • A file called ‘Install’ which was written by the Lucid developers and provides somewhat out of date information on how to check and install the Java software needed to run the key. You should follow the more up to date instructions set out in below.


Running the Lucid key from a web browser

Lucid keys can be run from within a web browser with the key held physically on either your computer or on a remote website. These instructions assume that you are running the key from your own computer.

You will need to have an up to date version of Java installed before you begin.

Copy the distributed files into a folder on your computer then double click on the following html file): … Deployed HTML version December 2015 > Cladonia of the British Isles V.4. December 2015 (HTML File).

Double click and your web browser will open. If you are using Internet Explorer the key will open immediately. If you are using the Edge browser select Open with Internet Explorer from the ‘More’ button (shown as … at the top right of the window). You may need to ‘Allow blocked content’ or otherwise agree to Java executing.


How to use a Lucid Key

We are all familiar with dichotomous keys in which you select from two choices (a couplet). Each choice leads to further couplets or to an identification. The problem with such types of keys is that if a choice is made in error, or a feature referred to in a couplet is poorly developed, then generally you will be unable to identify the unknown. In contrast, Lucid uses multi-attribute keys, where you are presented with a number of features that may be present in your unknown lichen. You can select from these in any order. As you select features the number of possible matching species is winnowed down until, you either find a unique match, or a small number of possible matches remain. The software can then be used to prompt you for the optimum means of distinguishing between the remaining possibilities until a match can be made.

The Lucid Player window comprises four sub windows:

Lucid Cladonia keyTop left: Features Available: this provides a list of those features that may be present in the unknown lichen. Features can be taken to mean characters or properties of the unknown and may include morphological, microscopic, chemical, or habitat features depending on the specific key being used. As features are chosen they are recorded in the lower left sub-window, see below.

Top right: Entities Remaining: this provides a list of those entities that are consistent with the choice of features made at any time. Entities in the lichen keys can be considered as a lichen species or lower-level taxa. Initially, the list of entities remaining will include all those lichens included in the key. As features are chosen the list of entities remaining will decrease and discarded entities are listed in the lower right sub-window, see below. To the left of each lichen species name is a page symbol. Clicking on this will open a window giving details of the species. This comprises a number of panels showing photographs, key distinguishing features of the lichen, a recent distribution map, the description taken from The Flora and copyright details.

Lower left: Features Chosen: This sub-window lists those features which have been chosen from the Features Available sub-window. It is possible to undo a choice of a feature from this window by clicking on the features tick box. This can be a useful method of determining the sensitivity of a feature by watching the number, if any, of entities discarded. Initially, the sub-window is empty but fills as features are selected.

Lower right: Entities Discarded:This sub-window lists those entities that have been discarded as not matching those features selected. Initially, the sub-window is empty but fills as features are selected.


Selecting Features

In general a feature is selected from the Features Available sub-window by clicking on its tick box. Features may be selected in any order. For convenience some features may be grouped in a hierarchical structure. This is shown by a + sign to the left of the Feature name. Clicking on this will expand the choices available. Where specialist terms are used to describe the various states a feature can take, a page symbol is shown to the left of the feature. Clicking on this will open a window giving definitions and examples of these states.

Most of the features in the lichen keys can have multiple states. In Lucid it is possible to select more than one state at the same time but take care how you use this feature as this may not be logically appropriate in all cases. Some examples may clarify this situation.

Colour of a feature – say there are options for grey, white, green, or black for the colour of part of a lichen. Since even a single lichen specimen may show more than one colour it is logically appropriate to select one or more colours. Species with any of the colours selected will be retained.

Presence or absence of a feature - Some features may be either present or absent in a single lichen species and for this reason both present and absent are included as logical responses in the key. However, as you are identifying a single instance of the lichen the feature will be either present or absent in that specimen. Therefore, it is logical to select either present or absent, depending on the individual specimen to be identified. However, it is not logical to select both present and absent at the same time.

Presence or absence of a multi-state feature - This may be considered a combination of the above two cases. A feature may be absent or present in a number of different states. Here it is logical to either select absent, if it is absent in the individual specimen being identified, or one or more of the possible states if it is present. However, it is not logical to select both absent and one or more of its possible states at the same time.

Numeric features are shown by an open box to the left of the features name. Clicking on this will open up a dialogue box. Before entering numeric data check the units expected , shown to the right of the input box. Numeric values may be entered in any of the following formats:

x (a single value);
x-y (a range between x and y);
(less than x);
(greater than y).


Tools to help distinguish between remaining species

Once you have entered some features and narrowed down the number of possible lichens to a manageable number Lucid provides a number of tools to help you optimise the selection of those features necessary to arrive at a unique identification.

Species Description & Distribution: Clicking the page symbol to the left of a lichen species in the Entities Remaining sub-window provides descriptive and photographic details of the lichen plus its current distribution. This may be sufficient to allow an identification to be made.

Best: This is invoked by pressing the key with the Magic Wand symbol on the toolbar. An algorithm finds the feature which best subdivides the remaining lichens into two similar-sized groups, thus halving those remaining. It is possible to apply this more than once and two adjacent keys allow you to scroll through your Best choices.

Shortcut: This is invoked by pressing the key with a Lightning strike symbol on the toolbar. A window is opened showing those feature(s) which will lead directly to a unique identification of a lichen species.