Not sure what weed you have? The Environmental Weeds of Australia Lucid key below contains 442 weeds and has been developed to help you to identify a weed using its unique combination of features. Once you have selected the characters of your weed using the checkboxes, the tool will provide you with a list of remaining weeds that fit the criteria – click on the image to enlarge it and, if you think that is your weed, click on the factsheet icon between the image and the weed name to view the relevant management profile.

Note that some species may not have associated management profiles.

This key is optimised on tablets and desktop computers only.

Click here to open the key

Handy guide to using this online weed key

Before attempting to use this online key to identify a weed, you should first become familiar with the key by scrolling through the Features Available and expanding the different features by clicking on the + symbol. This will then give you an idea of what features you should be looking for in your weed specimen. As you work through the key, you should quickly reduce the number of weeds left in the Weeds Remaining panel on the right.

Answer easy features first

You can start anywhere in the list of features, but it is recommended that you start by answering ‘Distribution characters – distribution by state’ to limit results to weeds known to occur in that jurisdiction. Next, it is recommended that you answer features like plant form, flower colour, leaf arrangement and leaf size– on a good specimen, these features can be easy to determine and you are less likely to make mistakes.

If you can’t decide which option is right

If you are having trouble determining the characteristics of your specimen, it is recommended that you skip those features or select all options that could apply. That way you can be sure that you do not incorrectly eliminate your weed from the Weeds 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

Once you have addressed some of the obvious features, you now can use the ‘Best’ function which will suggest the best feature to use to refine the list of remaining weeds. The ‘Best’ button looks like a wand and can be found above the Features Available panel. If the suggested feature is too difficult for you to answer or if you want to further refine the remaining weeds, click on the ‘Best’ button again.

What if no weeds remain?

If there are no weeds listed in the Weeds Remaining panel, this means that no weeds in the database have the combination of characters you selected. There are several possible explanations.

You may have made an error when selecting the characters of your weed. You should double check your selections in the Features Chosen panel and unselect any characters that you are uncertain about. Keep an eye on the Weeds Remaining panel to see if any weeds reappear. Try unselecting ‘Distribution characters – distribution by state’, in case the weed hasn’t been recorded in your state or territory before.

Alternatively, your plant might be a native species or a weed that is not included in the key. Consult your local weeds officer, herbarium, plant identification Facebook group or iNaturalist for help with identifying your plant – contact details and links are available in the Connect section.

What if several weeds remain?

The ‘Differences’ function can highlight the key differences between the weeds left in the Weeds Remaining panel. The ‘Differences’ function can be accessed via the list button, situated on the top menu bar between the Features Available and Weeds Remaining, which will open a window. The window shows the remaining weeds and has a dropdown at the top. Click on different features in the dropdown, starting with features at the top – these have the greatest degree of difference between the remaining weeds. Try different features until you have determined which weed best fits or until you have ruled out all of the remaining options.

Checking the result

Once you have made a preliminary identification, check the information and images in the attached profile for that weed to confirm the identification. If you think that you may have found a high priority weed (e.g. prohibited matter), you should notify the relevant authority – see contact details in the Report section.

If you don’t think the identification is correct, you should double check what you have selected in the Features Chosen panel. If you are still unable to identify your plant using the key, then you should consult your local weeds officer, herbarium, plant identification Facebook group or iNaturalist for help with identifying your plant – contact details and links are available in the Connect section.