Calomba Daisy

Pentzia suffruticosa (L.) J.B. Hutch ex Merxm.

Synonyms - Matricaria multiflora, Matricaria suffruticosa, Tanacetum suffruticosum.

Family: - Asteraceae.


Pentzia celebrates the Swedish botanist Pentz.

Suffruticosa is from the Latin suf or sub meaning under and fruticosis meaning shrub inferring it is smaller than a shrub.

Calomba Daisy because it was discovered near Calomba in South Australia and looks like a daisy.

Other names:




Stinking weed

Stinkkruid (South Africa)

Wurmbossie (South Africa)

Yellow top

Yellow weed


A robust, erect, strongly scented annual to 60 cm round with umbrellas of bright yellow flowers in early summer.




First Leaves:

Densely hairy.


Alternate, stalkless, grey-green, strongly aromatic. Does not form a rosette.

Petiole - none.

Blade - Grey green and aromatic. Egg shaped to oval in outline, 20-40 mm long by 10-20 mm wide, 2 or 3 times deeply lobed (i.e. the lobes have lobes also). Lobes parallel sided, less than 1 mm wide, with pointed tips. Hairy with glandular and non glandular hairs.


Almost woody, stout, erect or spreading, 300-600 mm high, often branched below the flower head. Scattered hairs.

Flower stem -

Flower head:

Many, bright yellow button discs, 4-5 mm diameter, in dense, flat topped corymbs at the ends of stems. 2-3 rows of green, keeled, 2 mm long bracts underneath.


All bisexual, yellow.

Florets - Yellow, 3 mm long, tubular, 4 lobed.

Ovary - Conical, elongated, naked receptacle.

'Petals' - None.

Stamens -

Anthers -


Achene, up to 2 mm long, cut off at an angle at the top, ribbed and hairy on the inner face. Pappus is a very small crown of white scales to 1 mm long.


Enclosed in the achene.


Taproot with branching laterals.

Key Characters:

Achene ribbed on the inner face. Conical, elongated receptacle. Involucre of 2-3 rows of equal, scarious bracts.


Life cycle:

Annual or biennial. Seeds germinate mainly in autumn and form a rapidly growing rosette over winter. Flower stems emerge in August and flower from October to November. In early summer the plant dies leaving the woody stems still carrying the seed. Late germinating plants may remain vegetative and survive the summer to flower in the following season.



By seed.

Flowering times:

October to November in SA.

Early summer in WA.

Seed Biology and Germination:

Seed requires bare ground for good establishment.

Vegetative Propagules:




Population Dynamics and Dispersal:

Spread by seed. Most spread is probably by flowering stems being broken off and moved by wind, animals or machinery because the seed is retained in the head for some time. Wind may spread some seed directly and it is moved in agricultural produce such as hay and cereal grain.

It establishes best on bare ground.

Origin and History:

South Africa.

Probably imported in fodder from South Africa in 1922. It was first collected in 1930 and remained insignificant for a number of years after that.



At Calomba, Parham, and Port Lincoln in SA.

Merredin, Esperance and Kalgoorlie in WA.



Semi-arid, sub-tropical shrub lands.


Sandy soils.

Plant Associations:

Shrub lands.



Used in folk medicine.


Persistent weed of crops, fallows, poor pastures, roadsides, grazed arid woodlands and disturbed areas.

Unpalatable and rarely eaten because of its strong smell.

Taints milk and meat if it is eaten.


Not recorded as toxic.


Noxious weed of SA.

Management and Control:

Late cultivation provides reasonable control. Grazing management and spot spraying are used on light infestations. Spray/graze with hormone herbicides or spray topping to reduce seed set are reasonably effective. Sulfonyl ureas are showing good activity.


Eradication strategies:

Spraying with glyphosate and cultivating 2 weeks later should control small areas.

Herbicide resistance:

Biological Control:

Related plants:

Globe Chamomile (Pentzia globifera)

African Sheep bush (Pentzia incana)

Plants of similar appearance:

Closely related to the Chrysanthemum.


Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P879.

Gilbey, D. (1989). Identification of weeds in cereal and legume crops. Bulletin 4107. (Western Australian Department of Agriculture , Perth). P40. Photos.

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. 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). #947.3.

Parsons, W.T. and Cuthbertson, E.G. (1992). Noxious weeds of Australia. (Inkata Press, Melbourne). P296-298. Photos.


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