Hawkweeds
- katemacquarrie22
- 2 days ago
- 2 min read
We often associate Asters with fall, but PEI has members of this family that flower in spring and summer too. Right now, the bright yellow and orange Hawkweeds (Hieracium and Pilosella species) can be spotted a mile away.
As a botanist-of-a-certain-age, it annoys me to no end that I must now list two genera for Hawkweeds. For hundreds of years, they were in the perfectly fine genus Hieracium. Then, in the late 20th century, taxonomists separated the Hawkweeds that can reproduce vegetatively via stolons (aka runners) into Pilosella, leaving those that reproduce only by seed in Hieracium. I’m not at all convinced this is an improvement.
The Island has more than 15 different species of Hawkweeds, along with a few subspecies and hybrids. All but two are introduced, with most of the newcomers having been established here for well over 100 years. Our three most commonly found species are shown in the photo, and I can guarantee you’ve passed them even if you haven’t noticed.
On the left is the species with the best common name: Mouse-eared Hawkweed (Pilosella officinarum). This yellow-flowered species usually has just one bloom per plant and is a great example of the unreliability of plant ID apps; every app I’ve tested has misidentified it as Dandelion even though the differences are obvious to the human eye.
Mouse-eared Hawkweed gets its name from the leaves. They are indeed rather ear-shaped, with long soft hairs on the tops (inset photo). Mouse-eared Hawkweed is lower-growing than most of the other species, usually less than 20 cm (eight inches) tall, but often much shorter in mowed areas.
The species most people are familiar with is Orange Hawkweed (Pilosella aurantiaca), also known as Devil’s Paintbrush (top right). This is our only non-yellow Hawkweed, and its orange-red flowers are distinctive. Childhood memories can be funny things. I distinctly remember the first time I was told the name of this plant. It was while on a picnic at the former Devil’s Punchbowl Provincial Park – so long ago that part this site was field rather than forest as it is now – and hearing about Devil’s Paintbrush at the Devil’s Punchbowl was scary to preschool-age me. Clearly, it didn’t derail my career in botany though!
The third common field species seen on PEI is Meadow Hawkweed (Pilosella caespitosa). This is a tall plant, often growing to 60 cm (two feet) and with clusters of yellow flowers atop the mostly-leafless stem. Leaves and stem are both covered in hairs, including some that are star-shaped if you look at them under a magnifying glass.
All three of these species spread vegetatively and can form dense patches, making them invasive in meadows and woodland edges. That said, they don’t concern me as much as some of the more shade-tolerant species such as Common Hawkweed (Hieracium lachenalii) which I find in forests, especially in parts of Central PEI.
Like them or not, Hawkweeds are here to stay as parts of PEI Untamed!