An erect, rough, stiff haired, annual to short lived perennial plant with a basal rosette of leaves and bright yellow flowers on the ends of branched stems in spring. The hairs are usually hooked and the leaves usually lobed and wavy.
Description:
Cotyledons:
Two. Oval, Tip round to slightly indented. Base Tapered. Hairless. Short stalk.
First leaves:
Club shaped, round tip, slightly toothed on the edges with bristles. Hairy on both surfaces.
Leaves:
Form a basal rosette.
Petiole - Base of leaf looks like a petiole.
Blade - Basal and lower stem leaves, narrowly egg shape, up to 70-200 mm long by 25 mm wide, irregularly wavy toothed or smooth edges with bristles. Acute tip. Narrowed into a petiole like base.
Stem leaves - Upper leaves, alternate, stiff hairs, narrowly egg shaped, up to 100 mm long by 20 mm wide, upper surface pimply, edges have short bristles, no petiole, clasp stem, occasionally edges of leaves continue down stem to form wings or have 2 rounded lobes. Tip acute or pointed. Base tapered. Most hairs have a wart base and some have 2 or more hooks at the top.
Stems:
Erect, stout, 300-1000 mm tall, stiff short hairs, rough, prickly and sticky to touch, irregularly branched. Most hairs have a wart base and some have 2 or more hooks at the top.
Flower head:
Single at the ends of short branches. Irregular, leafy corymb. Heads on short stalk(peduncle), cylindrical, about 10-15 mm long and wide with toothed bracts, hairy at the base and the top of the peduncle. 5 outer bracts leaf like, heart shaped, tip pointed, notched where they attach, stiff hairs. About 8-10 outer bracts, parallel sided or oval inner ones with stiff hairs and with a long, hairy appendage behind the tip that tapers to a point. All bracts enlarge as the flower matures.
Flowers:
Florets yellow, bisexual. All have 'petals' (ligulate).
Ovary - No bracts on receptacle.
'Petals' - Yellow, many.
Stamens -
Anthers -
Fruit:
Two types of achenes. Outer ones, 3-3.5 mm long, cylindrical, hairy, with a fine beak, white to yellow, hairy, lengthwise furrow, reduced pappus, persistent and embraced by flower head bracts.
Inner ones hairless, slightly curved, 2.5-4 mm long, crosswise wrinkled, lengthwise furrow, red or dark brown, with a fine beak and a pappus about the same length as the achene. Pappus usually falls off with the beak.
Seeds:
Enclosed in the fruit. 2.5-4 mm long by 1-2 mm diameter.
Roots:
Taproot.
Key Characters:
Outer involucre bracts ovate-cordate in 1 row.
Achene long beaked.
Biology:
Life cycle:
Annual to short lived perennial. Flowers November to January. Seeds germinate in autumn to spring.
Physiology:
Reproduction:
By seed.
Flowering times:
Summer to autumn in western NSW.
December to May in SA.
November to December in Perth.
Spring to January in WA.
Seed Biology and Germination:
Vegetative Propagules:
Hybrids:
Allelopathy:
Population Dynamics and Dispersal:
Spread by seed.
Origin and History:
Europe. Western Asia.
Distribution:
ACT, NSW, SA, TAS, VIC, WA.
Habitats:
Climate:
Temperate.
Soil:
Plant Associations:
Significance:
Beneficial:
Does not host Root Lesion Nematodes (Pratylenchus neglectus or thornei) (63)
Detrimental:
Weed of roadsides, pastures, irrigated areas, crops, fallows, gardens and disturbed areas.
Not eaten by stock.
Toxicity:
Not recorded as toxic.
Legislation:
None.
Management and Control:
Thresholds:
Eradication strategies:
Remove isolated plants by hand.
Spray small areas with Tordon 75-D in winter each year.
Selective herbicides are available for crops and pastures.
Herbicide resistance:
Biological Control:
Related plants:
Hawkweed (Picris hieracioides) is biennial to perennial
Picris squarrosa
Plants of similar appearance:
Capeweed (Arctotheca calendula) has a light underside and darker upper surface on the leaf.
Dandelion (Taraxacum officinale)
Flatweed (Hypochoeris radicata)
Fleabane (Conyza spp.)
Hawkbit(Leontodon taraxacoides)
Indian Hedge Mustard (Sisymbrium orientale)
Ox tongue (Helminthotheca echioides)
Prickly Lettuce (Lactuca serriola)
Prickly Sow Thistle (Sonchus asper)
Rapistrum (Rapistrum rugosum)
Slender Thistle (Carduus spp.)
Smooth Catsear (Hypochoeris glabra)
Skeleton Weed (Chondrilla juncea) has backward pointing leaf lobes.
Sow Thistle (Sonchus oleracea)
Wild Radish (Raphanus raphanistrum)
Wild Turnip (Brassica tournefortii)
References:
Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P110. Diagram.
Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P941. Diagram.
Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P402.
Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P717. Photo.
Hussey, B.M.J., Keighery, G.J., Cousens, R.D., Dodd, J. and Lloyd, S.G. (1997). Western Weeds. A guide to the weeds of Western Australia. (Plant Protection Society of Western Australia, Perth, Western Australia). P100.
Lamp, C. and Collet, F. (1990). A Field Guide to Weeds in Australia. (Inkata Press, Melbourne).
Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). #975.1.
Marchant, N.G., Wheeler, J.R., Rye, B.L., Bennett, E.M., Lander, N.S. and Macfarlane, T.D. (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P686-687.