Pilosella officinarum
Common name
hawkweed, mouse-ear hawkweed
Synonyms
Hieracium pilosella L.
Family
Asteraceae
Flora category
Vascular – Exotic
Structural class
Herbs - Dicotyledonous composites
NVS code
The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.
PILOFF
Conservation status
Not applicable
Habitat
Terrestrial. A plant of lowland, montane and subalpine habitats. Grows in sites with low to moderate fertility but appears to prefer moderate fertility. Shrubland, tussockland, cliff, bluff, riverbed and herbfield communities.
Wetland plant indicator status rating
Information derived from the revised national wetland plant list prepared to assist councils in delineating and monitoring wetlands (Clarkson et al., 2021 Manaaki Whenua – Landcare Research Contract Report LC3975 for Hawke’s Bay Regional Council). The national plant list categorises plants by the extent to which they are found in wetlands and not ‘drylands’. The indicator status ratings are OBL (obligate wetland), FACW (facultative wetland), FAC (facultative), FACU (facultative upland), and UPL (obligate upland).
FACU: Facultative Upland
Occasionally is a hydrophyte but usually occurs in uplands (non-wetlands).
Features
Perennial herb with rosettes and stolons 5-10 cm tall. Leaves 2.5-5 by 0.6-1.5 cm, glaucescent green above with white felt-like underside. Single yellow flower head per rosette, outer flower rays with red stripe.
Similar taxa
Pilosella officinarum is distinguished from other species by its large solitary pale yellow capitula and the dense stellate pubescence on stolons and beneath leaves.
Flowering
October, November, December, January, February
Flower colours
Yellow
Fruiting
November - April - (May)
Life cycle
Perennial. The hermaphrodite flowers are probably apomictic (produces viable seed without fertilisation) in New Zealand. Vegetative reproduction occurs through the production of rosettes by stolons (Timmins & MacKenzie 1995). Seed is prolifically produced at approximately 1000/dm squared but it is probable that no seed bank is formed (Timmins & MacKenzie 1995). Seed is dispersed by gravity and wind.
Year naturalised
1878
Origin
Europe, N. and C. Asia
Reason for introduction
Accidental
Tolerances
The plant is tolerant of drought; intolerant of shade; highly tolerant of frost and slightly tolerant of poor drainage. Highly tolerant to physical damage and grazing. Requires low to medium soil fertility.
Etymology
pilosella: Softly hairy
National Pest Plant Accord species
This plant is listed in the 2020 National Pest Plant Accord. The National Pest Plant Accord (NPPA) is an agreement to prevent the sale and/or distribution of specified pest plants where either formal or casual horticultural trade is the most significant way of spreading the plant in New Zealand. For up to date information and an electronic copy of the 2020 Pest Plant Accord manual (including plant information and images) visit the MPI website.