Aster means star and refers to the spreading 'petals' of the flowers of ornamental varieties.
Bushy Starwort - Bushy refers to the much branched form of the upper stem. Starwort is a combination of star referring to the flower and wort, which means weed.
Other Names:
Aster weed
Marsh Aster
Shrub Aster
Wild Aster
Summary:
Erect, many branched, almost hairless, spindly, dark green, summer growing annual or biennial herb, to 2 m tall. The leaves are small and held close to the stem. The flowers are also small and produce wind blown seeds with fluffy parachutes
Description:
Cotyledons:
Two.
Leaves:
Alternate, sometimes in clusters.
Stipules -
Petiole - None.
Blade - Narrowly oval to egg shaped or parallel sided. 25-155 by 3- 16 mm, smaller near top. Pointed tip. Fine stiff hairs on the margins. Margins entire.
Stem leaves - Smaller than lower leaves. Half clasping, no petiole.
Stems:
300-2000 mm tall. Almost hairless. Slender, tough, erect, stiff. Often single at the base, but many branched especially near top. Often reddish. Branches have a leafy bract at their base.
Flower head:
Many small heads in large, leafy, loose panicles. On ends of main stems and along smaller branches.
Involucre cylindrical 2-4 mm diameter, 3 or 4 rows of small, narrowly oval, papery, hairless bracts.
Flowers:
Bracts - 3-4 unequal rows of pale green to reddish or purple tipped bracts, 5-7 mm long.
About 25 female ray flowers in 2-3 rows with tongues or rays (ligulate). Tongues white or pink and turn blue when they dry. Tongues almost erect, slightly longer than the surrounding rows of bracts.
8-10 flowers in the disc section that are bisexual and tubular.
Ovary -
Receptacle - flat, naked, angular pitted.
Perianth -
Stamens -
Anthers -
Fruit:
Achene. Flattened, narrow, hairy. 2 mm long.
Seeds:
Flattened, narrow, 1.5-2 mm long. Hairy to sparsely hairy. 4-5 ribbed.
Pappus - About 30 soft bristles 6-10mm long in a single row.
Roots:
Taproot.
Key Characters:
Biology:
Life cycle:
Biennial, perennial or annual. Flowers at any time of the year with the main flowering occurring between November and February. Growth usually commences in spring and continues until drought or low temperatures occur. During winter leaf growth stops and stems become red.
Reproduction:
By seed.
Flowering times:
February to November in Perth.
Most of the year elsewhere in WA.
Seed Biology and Germination:
Vegetative Propagules:
None
Hybrids:
Allelopathy:
Ecology, Population Dynamics and Dispersal:
In mown lawns, it assumes a leafy prostrate growth form.
Origin and History:
North America.
Distribution:
ACT, NSW, SA, TAS, VIC, WA.
Habitats:
Prefers damp and poorly drained areas, but occurs in a wide range of habitats.
Climate:
Temperate.
Soil:
Prefers damp or poorly drained areas, but occurs on all soil types.
Plant Associations:
Significance:
Beneficial:
It is eaten when little other forage available but is poor quality.
Detrimental:
Weed of lawns, gardens, disturbed areas, pastures, irrigated areas (especially where ponds occur), drains and roadsides.
Toxicity:
Not recorded as toxic.
Legislation:
None.
Management and Control:
Thresholds:
Eradication strategies:
Herbicide resistance:
Biological Control:
Related plants:
New York Aster (Aster novi-belgi).
Plants of similar appearance:
China Aster (An ornamental garden plant) (Callistophus chinensis)
Fleabane (Conyza spp., Erigeron spp.)
Flatweed (Hypochoeris spp.)
Stinkwort (Dittrichia graveolens)
References:
Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P84. Photo.
Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P863-4.
Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P361. Diagram.
Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P662-663. 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). #140.1.
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). P657.
Acknowledgments:
Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.