Poached-egg Daisy

Myriocephalus stuartii (F.Muell. & Sonder ex Sonder) Benth.

Synonyms - Polycalymma stuartii.

Family: Asteraceae.

Names:

Myriocephalus is from the Greek myrios meaning many and cephale meaning head and refers to the many flower heads.
Stuartii commemorates Stuart.
Poached-egg daisy - because its flowers look like poached eggs and it is in the daisy family.

Other names:

Poached Eggs
Ham and Eggs Daisy
Fried Egg Plant
Bachelor's Buttons.

Summary:

A stout, erect, sticky, hairy, annual herb with long slender leaves and a white flower with a yellow centre like a poached egg.

Description:

Cotyledons:

Two. Narrow lance shaped. Tip pointed. Edges convex to parallel. Base tapered. Surface hairless.

First leaves:

Narrow lance shaped. Tip pointed. Dense short hairs.

Leaves:

Alternate.
Petiole - Absent.
Blade - Light green, long, narrow, parallel sided to lance shaped, 20-70 mm long. Tip pointed. Woolly hairs on top, sticky hairs underneath. Edges smooth.

Stems:

Erect, stout, 100-500 mm tall, somewhat tufted. Branch from the base or unbranched. Woolly or very sticky with glandular hairs.

Flower head:

Compound, hemispherical, white with a yellow centre like a poached egg, 20-40 mm diameter at the ends of long stems. Many rows of bracts with papery, woolly, claws with white, spreading, egg shaped, white blades, 5-7 mm long surround the numerous, yellow central flowers.
Partial heads, 4-9 flowered with 4-9, thin, egg shaped to oblong bracts that have tiny hairs towards the top. 2 of these bracts are underneath clawed bracts.

Flowers:

Tubular. Bisexual. Yellow.
Ovary - Receptacle naked.
'Petals' - White, 5-7 mm long.
Stamens -
Anthers - Tailed.

Fruit:

Black, cylindrical achene. Woolly or silky with long white hairs. Pappus with 8-13 bristles that are swollen towards the base, feathery from the base to tiny barbs near the top.

Seeds:

Roots:

Taproot.

Key Characters:

Erect plant. Compound head 2-4 cm across, large and showy. Bracts of general involucre with white opaque radiating laminae. Corollas 5 toothed. Upper leaves shorter than compound heads. Achenes silky with long white hairs.
White 'flowers' with a yellow centre resemble a poached egg.

Biology:

Life cycle:

Annual. Seeds germinate in autumn and winter. Flowers in spring. Most die with the onset of summer, though in favourable situations a few survive well into summer.

Physiology:

Reproduction:

By seed.

Flowering times:

Spring in western NSW.
Most of the year in SA.

Seed Biology and Germination:

Vegetative Propagules:

None.

Hybrids:

Allelopathy:

Population Dynamics and Dispersal:

Spread by seed.
Often occurs in dense almost pure stands especially when good autumn rains follow a dry summer.

Origin and History:

Australia.

Distribution:

NSW, NT, QLD, SA, VIC.

Courtesy Australia's Virtual Herbarium.

Habitats:

Sand plains and dune fields.

Climate:

Soil:

Sand plains and dunes.
Most abundant on stable deep red sands and sandy red earths. Less common on unstable dune crests.

Plant Associations:

Significance:

Beneficial:

Flower heads occasionally grazed. Rest of plant is unpalatable.

Detrimental:

Weed of crops.

Toxicity:

Not recorded as toxic.

Legislation:

None.

Management and Control:

Thresholds:

Eradication strategies:

Prevent seed set. Use clopyralid for control of existing plants and picloram based products to prevent later germinations.

Herbicide resistance:

Biological Control:

Related plants:

Woollyheads (Myriocephalus rhizocephalus)

Plants of similar appearance:

References:

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P923.

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P674. Photo.

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). #858.2.

Wilding, J.L. et al. (1987). Crop weeds. (Inkata Press, Melbourne). P58. Diagrams. Photos.

Acknowledgments:

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