Holcus lanatus
Environmental Weed (2024)
Common names
Yorkshire fog
Biostatus
Exotic
Category
Vascular
Structural class
Grasses
Simplified description
Tufted pale, greyish green, furry grass, velvety to the touch, up to c. 1 m tall, with a soft whitish, pale green, pinkish or purple flower head.
Flower colours
Green, Purple, Red/Pink, White
Detailed description
Tufted, sometimes stoloniferous, softly hairy, greyish green, perennial, 35–110 cm. Leaf-sheath firmly membranous, striate, ± keeled above near ligule, villous with long, fine, silky hairs, basal sheaths often purplish. Ligule (0.6)–1–3 mm, ± truncate, denticulate, apex finely ciliate and occasionally with a few long hairs, abaxially villous. Leaf-blade (2.5)–4.5–15–(20) cm × (1.5)–3–10 mm, pubescent and with longer soft hairs, narrowed to acuminate tip; margins finely ciliate, and with longer hairs. Culm erect, or ascending from geniculate base, nodes and internodes pubescent. Panicle 4–18 × 1.5–7 cm, lanceolate, ovoid or sometimes oblong, dense to lax, erect or nodding; rachis and branches pubescent. Spikelets 3.8–5.5 mm, whitish, pale green, or purplish. Glumes stiff-ciliate on keels and lateral nerves of upper glume, elsewhere minutely scabrid to shortly pubescent; lower sometimes slightly shorter, narrow-lanceolate, acute to mucronate, upper broader, elliptic, mucronate, or awned to 0.8 mm. Lemma 2–2.7 mm, elliptic-lanceolate, glabrous, shining, keel sparsely finely prickle-toothed, apex minutely ciliate-scabrid; lower lemma awnless, upper lemma narrower, awn stout, 1.4–2.8 mm, inserted c. 0.4 mm below tip of lemma, becoming recurved and uncinate. Palea keel sparsely short-ciliate above, apex obtusely lobed, minutely ciliate. Callus hairs few, to 1 mm. Rachilla glabrous. Anthers 1–2.2 mm. Caryopsis 1–1.5 × 0.4–0.5 mm.
Similar taxa
Another Holcus species, H. mollis, found in eastern and south western South island, is similar but forms loose swards, not dense tufts, has very hairy nodes and brown, rather than purple, veins on the sheath.
Distribution
Common throughout New Zealand.
Habitat
A wide range of disturbed wet and dry sites, often in fens.
Conservation status
Not applicable
Detailed taxonomy
Family
Ecology
Flowering
Spring to early summer
Fruiting
Summer to autumn
Year naturalised
1844
Origin
Europe
Reason for introduction
Pasture plant or seed contaminant
Control techniques
Rarely controlled, but can be controlled manually, mechanically or herbicidally depending on situation.
Life cycle and dispersal
Perennial. Seed dispersed by animals, water or contaminated machinery.
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). If you have suggestions for the Wetland Indicator Status Rating, please contact: [Enable JavaScript to view protected content]
FAC: Facultative
Commonly occurs as either a hydrophyte or non-hydrophyte (non-wetlands).
Other information
Etymology
holcus: From the Greek holkus, an old Greek name for grass.
Environmental Weed (2024)
This plant is named in a list of 386 environmental weeds in New Zealand 2024 prepared by DOC. 759 candidate species were considered for inclusion on this new comprehensive list of environmental weeds in New Zealand. The species considered were drawn from published lists of weed species, lists of plants that must be reported or managed by law if observed, existing national and regional programmes and agreements for pest management, and species already managed by the Department of Conservation (DOC). Candidate species were then assessed to see if they were fully naturalised and whether they have more than minor impacts in natural ecosystems. Read the full report here.
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.
HOLLAN
Referencing and citations
References and further reading
Johnson AT, Smith HA. 1986. Plant Names Simplified: Their pronunciation, derivation and meaning. Landsman Bookshop Ltd, Buckenhill, UK.
Edgar E, Connor HE. 2000. Flora of New Zealand. Vol. V. Grasses. Manaaki Whenua Press, Christchurch, NZ. 650 p.
Johnson PN, Brooke PA. 1989. Wetland plants in New Zealand. DSIR Field Guide, DSIR Publishing, Wellington, NZ. 319 p.
Champion P. et al. 2020. Freshwater Invasive Species of New Zealand 2020. NIWA publication. https://docs.niwa.co.nz/library/public/FreInSpec.pdf
Lambrechtsen NC. 1986. What grass is that? A guide to identification of some introduced grasses in New Zealand by vegetative characters. New Zealand DSIR Information Series no. 87.
Attribution
Factsheet prepared by Paul Champion and Deborah Hofstra (NIWA). Features description from Edgar and Connor, (2000).