Hieracium argillaceum
Common name
hawkweed
Synonyms
Hieracium lachenalii 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.
HIEARG
Conservation status
Not applicable
Habitat
H. argillaceum is very similar to H murorum but lacks square based leaves and has more (2-5, cf 1-2) leaves on flowering stems.
Detailed description
Erect perennial herb 20-75 cm tall. Leaves mostly in a basal rosette, but with some leaves present on flowering stems. Basal leaves 6-12 cm long by 2-5 cm wide, finely toothed, stem leaves smaller and more coarsely toothed. Multiple clusters of yellow flowers.
Similar taxa
The yellow flowers, lack of stolons, toothed leaves and few leaves on the stems separates this species from most other Hieracium in NZ. To separate from, H lepidulum and H. pollichiae, you need to look closely at the types of hairs on the small leaves (bracts) that make up the base of the flowerhead with a magnifying lens. H. argillaceum lacks long pale-tipped hairs present on H. lepiduim and H. pollichiae.
Flowering
November, December, January, February, March
Flower colours
Yellow
Life cycle
Terrestrial. Roadsides, rocky places, waste land, in scrub grassland and forest (Webb et al 1988).
Year naturalised
1940
Origin
Europe
Reason for introduction
Accidental
Etymology
hieracium: From the Greek hierax ‘hawk’. Pliny the Elder (AD 23 - AD 79) believed the plant to be eaten by hawks to improve their eyesight.
argillaceum: From the Latin argilla ‘clay’, meaning growing in argillaceouos soils
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.
References and further reading
Johnson, A. T. and Smith, H. A (1986). Plant Names Simplified: Their pronunciation, derivation and meaning. Landsman Bookshop Ltd: Buckenhill, UK.
Webb, C. J.; Sykes, W. R.; Garnock-Jones, P.J. 1988. Flora of New Zealand Volume IV; Naturalised Pteridophytes, Gymnosperms, Dicotyledons. Christchurch, Botany Division, D.S.I.R.