Hairy Hawkbit

Leontodon saxatilis Lam.

Synonyms - Leontodon hirtus, Leontodon hispidus, Leontodon leysseri, Leontodon taraxacoides, Thrincia hirta.

Family: - Asteraceae.

Names:

Leontodon is from the Greek words meaning lion's tooth and refers to the toothed leaves.

Hairy Hawkbit

Other names:

Common Hawkbit

Hawkbit

Lesser Hawkbit

Summary:

A yellow flowered biennial to short lived perennial herb with lobed leaves in a rosette, grapnel like hairs. It has yellow flowers that are greyish purple underneath mainly in spring and summer on an unbranched, leafless, long stem.

Description:

Cotyledons:

Two. The cotyledon is 10 to 15 mm overall, narrowly egg shaped. Tip rounded. Edges convex. Base tapered, Petiole shorter than the blade and merging with it. Surface hairless. The seedling has a very short hypocotyl and no epicotyl.

First leaves:

The leaves grow singly, the first being 15 to 20 mm long, narrowly egg shaped with a rounded tip and a short merging petiole. The edges are lightly scalloped or toothed. It carries scattered hairs on the upper and lower surface many them being grapnel hairs that have a distinctive shape with a 2-3 lobed tip reminiscent of a small grappling iron.

Leaves:

The leaves are all in the basal rosette.

Stipules -

Petiole - Merging, long or short.

Blade - Narrowly egg shaped to oblong, 20-250 mm long by 3-10 mm wide with edges more or less regularly scalloped into triangular lobes or toothed with the teeth tending to point forwards. Occasionally it is almost smooth edged or only toothed near the tip. The tips and lobes frequently curl upwards. Tip may be acute or obtuse. Covered with short, rough, simple and 2-3 lobed, grapnel like hairs on the upper and lower surfaces.

Stems:

One to several flower stems, up to 350 mm long arise from the rosette. These are circular in cross section and fluted, with a solid pithy core. They are not branched and when elongating have their apex turned downwards. Towards the base they carry grapnel hairs but are hairless towards the top.

Flower head:

Single on the end of the stem. Flower head (involucre) 7-11 mm long by 4-9 mm wide with about 12 similar sized bracts plus a few smaller outer bracts.

Flowers:

'Flower' 25 to 30 mm in diameter with numerous ligulate florets and yellow in colour.

Bracts - Leafy, narrowly oval, hairless or with short, rough, simple and 2-3 lobed, grapnel like hairs.

Receptacle - naked.

Florets - All with yellow ligules. Outermost ones are grey-violet underneath.

'Petals' - Yellow, spreading, 8-14 mm long, longer than the involucre.

Stamens -

Anthers -

Fruit:

Achene, cylindrical and tapering at each end, 3-6 mm long, rough, striped, crosswise wrinkled. Two types; the outer ones are thick, incurved with a ragged crown shaped pappus of small more or less united scales. The inner ones taper at the top, but scarcely beaked and have a pappus of about 12 feathery, broad based, bristles and an outer row of shorter finely barbed bristles. There is no stalk between the seed and its pappus.

Seeds:

Roots:

Thickened taproot

Key Characters:

No stalk between the seed and the pappus. Yellow flowers. Leafless, solid, unbranched stems.

Biology:

Life cycle:

Biennial or short-lived perennial. It germinates in autumn and spring and flowers in summer.

Physiology:

Reproduction:

By seed.

Flowering times:

Most of the year in western NSW.

Most of the year in SA.

October to November in Perth.

October to February in WA.

Seed Biology and Germination:

Vegetative Propagules:

None.

Hybrids:

Allelopathy:

Population Dynamics and Dispersal:

Origin and History:

Europe.

Distribution:

NSW, SA, TAS, VIC, WA.

In all parts of Tasmania.

Perth to Esperance in WA.

Habitats:

Climate:

Temperate. Mediterranean.

Soil:

Sands to grey heavy clay soils

Plant Associations:

River Red Gum communities.

Significance:

Beneficial:

Detrimental:

Weed of turf, pasture, waste areas, and occasionally in crops. Its greatest importance is as a weed in turf, and it is locally significant as a weed in pasture.

Not readily grazed.

Toxicity:

Not recorded as toxic.

Legislation:

None.

Management and Control:

Thresholds:

Eradication strategies:

Herbicide resistance:

Biological Control:

Related plants:

Bristly Hawkbit (Leontodon hispidus ssp. hispidus) has been found near Nornalup. Similar to Flatweed but rosette leaves are more hairy and the flower buds droop heavily before opening.

Plants of similar appearance:

Hawkbit is frequently confused with Cat's Ear and Dandelion and is often called 'Dandelion'. In the mature stage it is distinguished from the former by having an unbranched flower stem and from the latter by having a solid flower stem. The leaf shape is more regular than that of Cat's Ear and has a scalloped rather than a backwardly directed serrated edge like Dandelion. In the seedling the first leaf is rather longer and narrower than that of the other two species; the first leaf is longer and narrower and usually has its widest point about three quarters of the length towards the apex of the blade rather than half way along.

References:

Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P107. Diagram of seed.

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P940. Diagram.

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P715. 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). P102.

Hyde-Wyatt, B.H. and Morris, D.I. (1975). Tasmanian weed handbook. (Tasmanian Department of Agriculture, Hobart, Tasmania). P37. Diagrams.

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). #734.1.

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). P690.

Wilding, J.L. et al. (1987). Crop weeds. (Inkata Press, Melbourne). P57. Diagrams. Photos.

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.