Mouse-ear Hawkweed

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iMouse-ear Hawkweed

Conservation status
Secure
Scientific classification
Kingdom: Plantae
Division: Magnoliophyta
Class: Magnoliopsida
Order: Asterales
Family: Asteraceae
Genus: Pilosella
Species: P. officinarum
Binomial name
Pilosella officinarum
(L.) F.W.Schultz & Sch.Bip.
Synonyms

Hieracium pilosella L.

Mouse-ear Hawkweed (Pilosella officinarum, syn. Hieracium pilosella L.) is a yellow-flowered species of Asteraceae, native to Europe and northern Asia. It produces single, citrus-colored inflorescences. It is an allelopathic plant. Like most hawkweed species, it shows tremendous variation and is a complex of several dozens subspecies and hundreds of varieties and forms.

It is a hispid (hairy) perennial plant, with a basal rosette of leaves. The whole plant, with the exception of the flower parts, is covered in glandular hairs, usually whitish, sometimes reddish on the stem. The rosette leaves are entire, acute to blunt, and range from 1-12 cm long and 0.5-2 cm broad. Their underside is tomentose (covered with hair). The flowering stem (scape) is generally between 5 cm to 50 cm tall, and sprouts from the centre of the basal rosette. The flowerheads are borne singly on the scape and are a pale lemon-yellow colour, with the outermost ligules having a reddish underside.

The plant favours dry, sunny areas. It grows well on sandy and similarly less fertile ground types. It produces stolons are which generate a new rosette at their extremity, each rosette has the possibility of developing into a new clone forming dense mats in open space. It also propagates by seeds.

It is a known allelopathic plant, whose roots secrete several substances inhibiting root growth,[1] including its own. It can be controlled through rotation with clover and grasses where possible.[1]

[edit] Cultivation and uses

Mouse-ear Hawkweed has become a common introduced invasive species in North America (where it is found in southern Canada and both northeast and northwest U.S.), and New Zealand. It is a level C noxious weed in the United States (with higher levels in the states of Washington and Oregon), and a weed in Quebec. It does not have special designations in other locations of Canada. It is known to be strongly invasive in New Zealand's tussock fields, where there are no native species of hawkweed, and biological control measures are being undertaken to control it and other hawkweed species.

Tournefort mentions that blades covered in this plant's juices were believed to cut through stone as easily as through wood.[2]

[edit] Medicinal uses

The Mouse-ear Hawkweed contains umbelliferone, a compound similar to coumarin and a known antibiotic against brucellosis,[3] as well as a frequent active compound in sunscreen lotions. The plant is also a potent diuretic.

[edit] References

  1. ^ a b Carol Piening (1988-08-29). Element Stewardship Abstract for Hieracium Pilosella. The Global Invasive Species Initiative.
  2. ^ Hieracium pilosella in the online Flore Laurentienne
  3. ^ Bishop, G. F., A. J. Davy (March 1994). "Hieracium Pilosella L. (Pilosella Officinarum F. Schultz & Schultz-Bip.)". Journal of Ecology 82 (1): 195-210. ISSN 0022-0477. Retrieved on 2006-11-17.