Station 8: Invasives

Now, you will turn off of the path to the left, into the large clearing. Stop and look around at the tall growth. Can you tell what shouldn’t be there? 

Himalayan Blackberry

It’s actually much harder than you would think. UBNA suffers largely from invasive plant growth- plants that were somehow introduced, and gained control over the landscape. These plants often don’t have natural enemies in their new places, and are able to grow unchecked, often choking out the other native plants. The biggest problem for UBNA is the Himalayan Blackberry.

Young Himalayan Blackberry

            The Himalayan Blackberry is most easily recognized by its course, serrated, palmate leaves and its nasty red thorns. You will often see it overtaking shrubs, or lying close to the ground, waiting to snag your pants. From personal experience, it is difficult to pull from the ground, and once the struggle has ended, it is likely that more blackberry will await you. It will grow edible blackberries. The Himalayan Blackberry is so widespread in King County that property owners aren’t required to control the species, although it is recommended in protected and natural areas. (1)

            Another unexpected invasive is the Yellow Flag Iris. 

Yellow Flag Iris

You will see these increase in number as you draw towards the pond. These plants are the more attractive of the UBNA invasives, looking like bulbs that will sprout pastel flowers come spring. The irises I observed for 10 weeks grew to be about one to two feet tall, and did sprout pretty yellow flowers, that opened up with three large petals. They were initially brought over from overseas as an ornamental plant, but spread. It actually sickens animals and may provide irritation upon contact with human skin. (2) UBNA is lightly managed, which includes periodic removal of invasive plants. Invasive plants and animals are a large threat to ecosystems as they disrupt the balance. Always be careful not to transfer plants to different ecosystems or release household pets, as they too may become an invasive species. Walk on to Station 9.