Handy guide to using this online weed key

Before attempting to use this “online key” to identify a weed species, you should first become familiar with the key by scrolling through the Features Available and opening the different feature-states for each of these features (by clicking on the + symbol). This will then give you an idea of what you should be looking for in the weed specimen you want to identify to make it easier for you to proceed through the identification process.

Next, it is recommended that you open the feature “Distribution Characters” and “Distribution – by State” and select the State or Territory where you found the weed by ticking the relevant box. This will give you a specific key for the weed species known to be in that State or Territory – the number of species in this sub-key is indicated at the top of the entities panel (Entities Remaining).

If you want to view a larger image, simply click on the image and it will become full size.

Answer easy features first

Since you can select any feature and feature-state from any position in the list, it is best to proceed first to those features which are distinctive and where you are confident that you can select a Feature-state that describes what you observe for the plant specimen. For instance, one of the easiest Features is likely to be “Plant form”, that includes, shrubs, vines, aquatic plants, etc.

As you work through the key by addressing those Feature-states that you can easily identify, you will quickly reduce the number of weed species left in the Entities remaining panel.

Choosing multiple states

If you are uncertain which feature-state is the correct one to choose for the plant you are examining, choose additional states that you think might be correct. The Lucid software is designed to allow you to choose as many states as you require from any one feature since, within the program’s logic, these states will be connected by an “or” link. This will cause Lucid to search for all taxa with any of the states you select. As a general rule, if you are unsure which of two or more states your specimen has, then choose them all. That way you can be sure that you do not remove a weed species from the weed species (Entities Remaining) panel that could turn out to be the species you have found.

Finding the best feature to address next:

When you have selected all the obvious feature-states, you now have the option of using the Lucid “Find Best” function to suggest the best remaining feature to look at. At the top of the Features Available panel you will see the   “Find Best” icon. Click on this and the software will calculate the next best available feature that has the most chance of reducing the remaining weed species. If this “best” feature is a difficult one for you to distinguish which state is likely to be the case for your specimen, simply click on the Find Best icon again to recalculate the next best feature to address.

What if no weed species remain?

This will happen sooner or later in one of your weed identification sessions. If there are no weed species listed in the Entities Remaining panel, this simply means that no taxa in the database match the selection of feature-states you have made. There are several explanations possible.

The most common is that the plant is not a weed or that you have made an error in one or more Feature-states that you have selected. Therefore, review the feature-states you have chosen and decide which ones you are uncertain about. Try unselecting the uncertain states one by one to see what effect this has on the species remaining; whether one or more weed species move back into the Entities Remaining panel. Review the fact sheets and images for these remaining species to check whether you made an incorrect decision about a feature-state. and check on any information in the fact sheets about native species that might be confused with these remaining weed species.

If this does not result in an identification, it may be that the weed you have found is not currently recorded in the State or Territory you selected. Unselect that State/Territory and see what effect that has on the Entities remaining. There is the unlikely possibility that you have found a species not previously recorded in your State/Territory or, if there is still no remaining weed species in the Entities Remaining panel, it may be a new record for Australia – in either case you should report this to the appropriate authority.

What if several weed species remain?

Sometimes, after you have selected all the relevant Feature-states that you are able to, you still have several weed species remaining in the Entities panel. At least you will be much closer to an identification than you otherwise would have been and can now try another option that may help you identify your specimen: namely, the “Differences” function that can be accessed via the = icon, situated on the top menu bar. Clicking on Differences opens a Differences panel that shows a list of weed species that have not been discarded. You can then select a feature from the drop-down list of features for which there is at least one species that has a state that differs from the others. The list of features is based on the degree to which they differ between the remaining species, the features associated with the greatest difference between species being at the top of the list. Note the list also includes numeric features.  Choosing the characters highest on the list and most easily recognised should help you make an identification, or at least reduce the short list

Checking the result

Once you have made a preliminary identification, check the information and images in the Fact Sheet for that weed species either to confirm the identification or to go back and review the feature-states selected. You can also use the Differences function and Fact Sheet data to recheck the short list of weed species. If you are concerned that you may have found a prohibited or restricted weed, you should notify the relevant authority.