Globe Chamomile

Oncosiphon piluliferum (L.f.) Kallersjo

Synonyms - Matricaria globifera, Pentzia globifera.

Family: Asteraceae.

Names:

Pentzia celebrates the Swedish botanist Pentz.
Globifera refers to the globular flower heads.
Globe Chamomile refers to the globe like flower heads.

Other names:

Matricaria because it was previously in the Matricaria genus

Summary:

A deeply lobed leaf, erect, annual plant with globular, yellow flower heads in spring on long stalks and with an objectionable smell.

Description:

Cotyledons:

Two. Oval. Tip round. Base tapered. Hairless. No petiole.

First leaves:

Hairy, narrowly egg shaped with an acute tip.

Leaves:

Alternate. Forms a rosette. Strong objectionable smell.
Stipules - None.
Petiole - None.
Blade - Green. Egg shaped to oval in outline, 2 times deeply lobed (i.e. the lobes have lobes also). Lobes parallel sided, less than 1 mm wide, with pointed tips. Hairy with fine hairs.
Stem leaves - Clasping.

Stems:

Erect, up to 800 mm tall, much branched, longitudinal grooves. Hairy with fine hairs.

Flower head:

Globular, 10 mm diameter, on the ends of long stalks. 2 rows of bracts underneath the flower head.

Flowers:

Yellow. At ends of stems.
Ovary - Conical, elongated receptacle.
'Petals' - None.
Stamens -
Anthers -

Fruit:

Achene, 1-2 mm long x 0.5-1 mm wide, curved, ribbed on the inner face. Pappus is a very small crown of white scales to 1 mm long.

Seeds:

Enclosed in the achene.

Roots:

Taproot.

Key Characters:

Alternate, grey-green, deeply divided, strongly aromatic leaves.
No petiole.
Forms a rosette.
Yellow button-like flowers.
Achene ribbed on the inner face. Conical, elongated receptacle. Involucre of 2 rows of equal, scarious bracts.

Biology:

Life cycle:

Annual. Germinates in Autumn/winter. Flowers in spring.

Physiology:

Reproduction:

By seed.

Flowering times:

Spring.

Seed Biology and Germination:

Vegetative Propagules:

None.

Hybrids:

Allelopathy:

Population Dynamics and Dispersal:

Spread by seed.

Origin and History:

South Africa.

Distribution:

VIC, WA.

Courtesy Australia's Virtual Herbarium.

Habitats:

Climate:

Temperate.

Soil:

Plant Associations:

Significance:

Beneficial:

Detrimental:

Weed of crops, pastures, roadsides, fallows and disturbed areas.

Toxicity:

Not recorded as toxic.

Legislation:

None.

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.

Thresholds:

Eradication strategies:

Spraying with glyphosate and cultivating 2 weeks later should control small areas.
Velocity® (Bromoxynil + pyrasulfotole) has provided the best control in cereals.

Herbicide resistance:

None reported.

Biological Control:

Related plants:

African Sheep bush (Pentzia incana) not in WA.
Calomba Daisy (Oncosiphon suffruticosum)
Matricaria recutita found near Coorow.
Matricaria matricarioides now called Matricaria discoidea is not in Australia.

Plants of similar appearance:

References:

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). #947.1.

Wilding, J.L. et al. (1987). Crop weeds. (Inkata Press, Melbourne). P60. Diagrams. Photos.

Acknowledgments:

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