Pre-lab for Session 3

This "pre-lab" takes about 10-15 minutes.

Read the text and watch the short videos below. Use a piece of scratch paper to jot down a few words and phrases that are important to you or spark your curiosity.

Ideas that are introduced below will be explained in more depth during Session 3.

Japanese knotweed

Japanese knotweed identification

Japanese knotweed is part of the "knotweed complex." A complex is a group of closely related plants that includes species, cultivars, and hybrids. For this reason, identification can be challenging. However, identification is not an obstacle to volunteer activities. Find out more by reading this PDF. (You can ignore links in this PDF.)

Interactive module on Japanese knotweed

Follow this link to a "Learning & assessment module" by the Midwest Invasive Species Information Network.

  • This activity takes 3-6 minutes.

  • You may click on images to magnify them.

  • You may take the quiz as an anonymous guest. Your score is only for you. It will not be sent to Pesky Plants staff.

Seven Phenophases

(You will notice this section repeats what you reviewed for wild parsnip. Wild parsnip and Japanese knotweed are similar enough that they go through the same phenophases. The species look different, but their phenophase definitions are virtually the same.)

Every time you observe a plant, you will check for the presence or absence of 7 phenophases. Answer choices are "Y" for yes, "N" for no, "?" for unsure, and blank if you did not check. All 7 phenophases have precise definitions, which will be explained in Session 3.

  1. Initial growth

  2. Leaves

  3. Flowers or flower buds

  4. Open flowers

  5. Fruits

  6. Ripe fruits

  7. Recent fruit or seed drop

Intensity questions

For certain phenophases, when you answer "yes," you will be asked for more details. These "intensity questions" entail counting or estimating. Intensity questions always use a multiple choice format.

Join Session 3 to explore phenophases in depth.


You're done with the pre-lab for Session 3! Thank you!