Mouse ear hawkweed is a European native, introduced to North America, where it has
escaped. In some regions of the Pacific northwest it is considered an invasive species.
Identification: Mouse ear hawkweeds are exceptionally
hairy, even for hawkweeds—especially the leaves, whose undersides are soft enough to have earned
the name “mouse ears.” Upper leaf surfaces are also covered with coarser long white hairs.
Plants have a basal rosette of leaves which are unlobed, elliptic, pointed to blunt, and
⅜-4" (1-10 cm) × ⅛-¾" (5-20 mm). Leaves have a prominent white midvein.
Solitary yellow flowers appear 1¾-20" (5-50 cm) above the
base of leaves, on stems with stiff dark hairs and no leaves, each flower up to 1" (2.5 cm) across. They
appear from June to September.
Common catsear, Hypochaeris radicata,
looks similar, but its leaves are slightly lobed and less hairy.
Medical: In the Middle Ages, the milky sap secreted by
this species, then called Auricula muris, was used as a cough remedy and for lung ailments.
All hawkweeds secret this bitter sap, but this sap is somewhat less more palatable. This same astringency led to its use as a clotting agent for wounds.