False Onion Weed

Nothoscordum borbonicum Kunth and

Nothoscordum gracile (Aiton) Stearn

Synonyms - Allium fragrans, Allium roseum, Allium orientale, Nothoscordum inodorum, Nothoscordum fragrans.

There is some debate over whether the two species should be amalgamated.

Family: - Alliaceae

Names:

Nothoscordum

Borbonicum

Gracile

False Onion Weed refers to it similarity to Three-cornered Garlic (Allium triquetrum) which is often called Onion Weed. False may allude to the fact that it doesn't have an onion like odour.

Other Names:

Fragrant False Garlic.

Onion Weed.

Wild Onion.

Summary:

A persistent, perennial herb to 1 m tall with clusters of sweet scented, 6 petalled flowers on a cylindrical stem in spring and 2-10, long shiny, strap-like leaves that arise from a bulb in autumn and wither over summer. It has an annually renewed bulb and produces many seeds and underground bulbils. It does not have the onion-like smell of Three-cornered Garlic.

Description:

Cotyledons:

Two.

First leaves:

The first leaves from the seed or bulbils are fine and thread-like. The first leaf from the bulb is fleshy.

Leaves:

2-10 strap-like, arising from a bulb (basal). Little or no onion-like smell when crushed. Shorter than or equal to the flowering stem.

Stipules - None.

Petiole - None.

Blade - 200-300 mm long by 4-20 mm wide, flat, strap-like, 17-20 lengthwise veins. 190-230 mm long by 2-9 mm wide. Tip pointed. Edges parallel. Base sheathing for less than one tenth of the flower stem (scape).

Stem leaves -

Stems:

Flower stem - Erect, cylindrical, (150)300-600(1000) mm tall by 5 mm wide, hollow or sometimes solid for part of its length, unbranched.

Flower head:

Terminal umbel of 8-25 flowers. Flowers are on stalks (pedicels) in dense clusters which are subtended by two bracts (spathe) that overlap at the base and are at the end of a long stem (scape). Few to many flowered loose umbel. Pedicels (10)20-45 mm long, erect. Scape 300-600(1000) mm long. Spathe is persistent, about 10 mm long or less than half as long as the pedicels and has pale red brown markings. Flowers initially enclosed in spathe.

Flowers:

White to faint pink or faint purple, fragrant flowers with 6 petals and a conical base. Bisexual.

Ovary - Superior, 3 celled. 4-12 ovules per cell (loculus).

Style - terminal.

Stigma - entire.

Petals (tepals) - Six, 8-15 mm long by 3-5 mm wide with pointed tips. White to faint pink or faint purple with a pale green to brown marking on the mid vein. Conical tubular at the base.

Stamens - Short, attached to segments just above the base of the perianth. Half as long as the perianth

Filaments - 7-8 mm long, simple, linear and slightly broader at the base

Anthers - Yellow, Prominent. 6.

Fruit:

Oval capsule, 5-8 mm long with 3 segments (locules). Dehiscing loculicidally.

Seeds:

Black, many, angled, 2 mm long.

Bulbils are formed at the base of the bulb, but there are none on aerial parts of the plant.

Roots:

Single, white globular bulb more than 15-20 mm wide producing many basal bulbils during the growing season. Fibrous but somewhat fleshy roots.

Bulb with membranous tunic.

Key Characters:

Little or no onion-like odour when crushed.

Flowers in umbels.

Perianth of 6 segments connate into a short tube at base.

6 stamens.

Pistil free from stamens.

Style terminal.

Ovary superior.

Ovules usually 4-12 per loculus.

Adapted from Burbidge, Harden

Biology:

Life cycle:

Perennial. Leaves emerge from bulb in autumn and grow over winter. In spring the flowering stem elongates and produces terminal clusters of 6 petalled, white flowers. The flowers produce seed and the bulb regrows and many underground bulbils are produce also. Seed and bulbils germinate in autumn but don't usually produce flowers until the following seasons after the bulb has increased in size.

Physiology:

Reproduction:

By seed, bulbils and bulbs.

Flowering times:

September to December in NSW.

October to November in Perth, WA.

October to January in WA.

Seed Biology and Germination:

Vegetative Propagules:

Bulbs and bulbils.

Hybrids:

None.

Allelopathy:

Population Dynamics and Dispersal:

Dispersed by water and ants mainly.

Dumping of garden waste is another common method of dispersal to new areas.

It has been cultivated as a garden plant and is common around old settlements.

Origin and History:

Native to America.

Almost cosmopolitan.

Distribution:



Nothoscordum gracile
Courtesy Australia's Virtual Herbarium.





Nothoscordum borbonicum
Courtesy Australia's Virtual Herbarium.

ACT, NSW, QLD, SA, TAS, VIC, WA.

Lord Howe Island. New Zealand.

Habitats:

Tends to occur in slightly depressed and moister parts of the landscape and in disturbed areas.

Climate:

Temperate and Mediterranean.

Soil:

Sands, sandy clay

Plant Associations:

Significance:

Beneficial:

Ornamental garden plant.

Detrimental:

Weed of lawns, roadsides, disturbed areas, bushland and gardens.

It is a common weed of turf and gardens in temperate Australia.

Toxicity:

Not recorded as toxic.

Legislation:

None.

Management and Control:

Herbicides are the most effective method of control. Iodosulfuron provides good control in Kikuyu, Buffalo and Couch (but not Queensland Blue Couch) turf or lawn and some other perennial grass species.

It is difficult to control manually.

It is relatively tolerant to mowing and slashing.

Thresholds:

Rarely a weed of crops.

Eradication strategies:

Very difficult to eradicate manually because the bulblets break off easily and it produces quantities of seed.

For small areas use 1 g iodosulfuron(50g/kg) plus 25 mL Pulse in 10 L water and spray until just wet in winter and repeat for 2-3 years.

Herbicide resistance:

None reported.

Biological Control:

None.

Related plants:

No other Nothoscordum species.

Other species in the Alliaceae family include:

Leek (Allium porrum)

Naples Onion (Allium neopolitanum)

Three-cornered Garlic (Allium triquetrum)

Cultivated species include Allium, Agapanthus, Tulbaghia.

Plants of similar appearance:

Three-cornered Garlic.

References:

Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P19. Photo.

Bodkin, F. (1986). Encyclopaedia Botanica. (Angus and Robertson, Australia).

Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P108.

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P191. Photo.

Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney).

Harden, Gwen J. (1991). Flora of NSW. (Royal Botanic Gardens, Sydney). Volume . P102. Diagram.

Hussey, B.M.J., Keighery, G.J., Cousens, R.D., Dodd, J. and Lloyd, S.G. (2007). Western Weeds. A guide to the weeds of Western Australia. (Second Edition). Plant Protection Society of Western Australia, Perth, Western Australia. P8. Photo.

Lazarides, M. and Cowley, K. and Hohnen, P. (1997). CSIRO handbook of Australian Weeds. (CSIRO, Melbourne). #744.2.

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). P783.

Moore, J.H. and Wheeler, J.R. (2008). Southern Weeds and their Control. (Second Edition). South Coast NRM and Department of Agriculture and Food Western Australia. P36.

Muyt, A. (2001). Bush Invaders of South-East Australia: a guide to the identification and control of environmental weeds found in South East Australia. (R.G and F.J. Richardson, Australia). P87.

Paczkowska, G. and Chapman, A. (2000). The Western Australia flora: a descriptive catalogue. (Wildflower Society of Western Australia (Inc), the Western Australian Herbarium, CALM and the Botanic Gardens & Parks Authority). P29.

Randall, J.M. and Marinelli, J. (1996) Invasive Plants. (Brooklyn Botanic Gardens Inc. Brooklyn). P. Photo.

Roy, B., Popay, I., Champion, P., James, T. and Rahman, A. (1998). An Illustrated Guide to Common Weeds of New Zealand. (New Zealand Plant Protection Society). P28.

Acknowledgments:

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