Mouse-ear Hawkweed (Hieracium pilosella)

 
 
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Description
Perennial with stems to 40 cm high. Leaves basal or on stolons, broader above the middle, to 10 cm long, upper surface with scattered long coarse simple hairs, lower surface with fine non-glandular hairs and dense covering of star-shaped hairs.

Flower heads solitary at the end of each leafless stalk. All small flowers (florets) strap shaped, deeply 5-toothed, yellow, often with a red stripe on the outer face. Seeds cylindrical, ribbed, about 2 mm long and about 0.5 mm wide, with a flattened apex, ribs ending at the apex in minute points, top of seed with pale brown bristles to 6 mm long in one row.

Key Identifiers
  • Solitary yellow flowers, with square edges than are notched, often with a red stripe on the outer face
  • Leaves, stems and buds covered in bristly hairs
  • Upper leaf surface with long simple hairs, lower surface whitish from a dense mat of short, star-shaped hairs
  • At flowering produces rhizomes and/or stolons
Location in Canada
British Columbia, New Brunswick, Newfoundland, Nova Scotia, Ontario and Quebec all have reported infestations. There are none in Alberta, so far.

Resources Similar species
Native Hawkweeds (Hieracium sp) Many native hawkweeds are in North America but none will produce stolons and their flowers are not solitary. Refer to resources for hawkweed identification key.

Nicole Kimmel, ARD

Nicole Kimmel, ARD

Nicole Kimmel, ARD

Nicole Kimmel, ARD

Nicole Kimmel, ARD


 
 
 
 

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For more information about the content of this document, contact Nicole Kimmel.
This document is maintained by Shelley Barkley.
This information published to the web on April 10, 2012.
Last Reviewed/Revised on March 21, 2014.