Hieracium pilosella

Heracium pilosella, also known as Pilosella officinarum, commonly called Mouse-Ear Hawkweed, is a small perennial medicinal plant.  In the garden, this formidable competitor will be used as a groundcover, especially in dry and well-drained soils where it prevents the germination and development of weeds. It is effective, but also ornamental when it spreads on the ground in a slightly silver carpet dotted with dandelion-like flowers in a light lemon yellow colour. Its low-growing rosettes creep between the rocks in rockeries or in paving joints, vegetating in the inhospitable and stony areas of the garden.

Pilosella officinarum belongs to the large family of Asteraceae, it is a cousin of dandelions, sunflowers, and centaureas. It is a perennial plant native to a vast area ranging from Western Europe to Western Asia. It is also present in North Africa. It is a hardy plant that thrives in dry soils and can adapt to various climates.

The Mouse-Ear Hawkweed forms rosettes of evergreen oblong leaves, green on top, greyish and downy underneath, covered with long silky and silver hairs. At the periphery of the rosettes, the plant develops leafy stolons that root upon contact with the ground, giving rise to new rosettes of leaves. The plant only measures a few centimetres in height, 10 to 15 cm (4 to 6in), but it spreads rapidly and can cover more than 50 cm (20in) on the ground. The flowering, which occurs over a long period of time, takes place from May-June to September depending on the climate. From the centre of the rosettes emerge 25 cm (10in) stems bearing lemon yellow inflorescences that resemble those of dandelions. These are 2 to 3 cm (1in) diameter flower heads that will give way to seeds equipped with silky, greyish to reddish crowns that the wind will disperse. The plant releases substances into the soil that inhibit the development of its competitors through a phenomenon called allelopathy. It sometimes self-destructs, with the rosettes in the centre of the carpet withering away. Rain leaches the exposed areas, and the soil becomes welcoming again for seeds to germinate and give rise to new individuals at the heart of the carpet. The taproot of Heracium makes it difficult to uproot.

The Mouse-Ear Hawkweed, requiring very little maintenance, is a unique groundcover for poor and well-drained soils. However, the plant can become invasive, and its growth can be limited by installing anti-rhizome barriers or by regularly removing unwanted stolons. Being hardy and highly water-efficient, it greatly reduces the proliferation of weeds and gives a precious and well-maintained appearance to the garden. This plant allows you to avoid the watering necessary for a lawn, even in dry climates, or in slightly inaccessible areas that are rarely walked on. It can be associated with other vigorous groundcovering plants such as Phyla nodiflora or Achillea crithmifolia. The pretty silver rosettes of the Mouse-Ear Hawkweed effectively and elegantly cover the ground of established perennial flower beds or beneath deep-rooted shrubs. It also provides an effective and ornamental solution to dress up a rocky and arid slope where nothing else grows.

Properties:

Heracium pilosella contains active principles recognized by modern pharmacology. It has antibiotic, detoxifying, astringent, cholagogue, appetizing, depurative, vulnerary, detergent, and diuretic properties. Pilosella powder is also used to stop nosebleeds.