Sandplain Lupin

Lupinus cosentinii Guss.

Synonyms - Lupinus digitatus. Lupinus varius, Lupinus hirsutus and Lupinus pilosus are sometimes misapplied.

Family: Fabaceae.

Names:

Lupinus is from the Latin word for wolf and applied because they prey on the soil and inhabit poor soil types.
Sandplain Lupin because they inhabit the sandplains.

Other names:

Blue lupin
West Australian Blue Lupin

Summary:

Sandplain Lupin is an erect, robust, much branched annual herb or shrub with 9-13 finger-like leaflets, 5-15 mm wide radiating from a central point. It has blue pea-type flowers that have a yellow-white “eye” which turns blue with age. The flowers are arranged in rings up the tall flower spike in spring producing pods with wrinkled brown seed. The densely hairy seed pods are 40-60 mm long with 3-5 mottled grey-brown, wrinkly, flattened seeds.
Native to the Mediterranean region, it is a common weed of roadsides and ungrazed areas, sometimes invading bushland and flowering in winter and spring.

Description:

Cotyledons:

Two. Hemispherical, thick, dark green, shiny.

First leaves:

Similar to later leaves.

Leaves:

9-13 finger-like leaflets attached to a central point.
Stipules - narrow and tapering to a fine point.
Petiole - yes.
Blade - Of leaflets, 25-70 mm long x 5-15 mm wide, oblong to egg shaped. Hairy on top and underneath.

Stems:

Strong, many branched, 200-1400 mm high. Short white or brownish erect hairs.

Flower head:

Raceme, 50-150 mm long on a stout stalk (peduncle) to 40 mm long.

Flowers:

Pea type flowers in rings, on stalks (pedicels) 2-4 mm long. Not scented.
Bracts - 3-7 mm long and parallel sided.
Ovary - Sessile. Style hairless, incurved. Stigma terminal.
Calyx - 10-12 mm long. Dense silky hairs. Tube 2-2.5 mm long. Upper lip 6-7 mm long with 2 deep lobes. Lower lip 7-9 mm long with 0-3 shallow lobes.
Petals - Blue. Standard petal, 12-17 mm long, has a yellow-white eye that becomes purple with age and an egg shaped limb. Wing petals, 12-17 mm long. Keel petal has pointed dark tip.
Stamens - United in a tube.
Anthers -

Fruit:

Pod, 40-60 mm long x 13-17 mm wide with 3-5 seeds. Densely hairy.

Seeds:

Grey brown with dark markings, flattened, circular in outline and 6-9 mm diameter. Deeply wrinkled to finely warty. Narrow crescent at the point of attachment.

Roots:

Strong taproot. Nitrogen fixing nodules on roots and especially at the top of the taproot. Top of taproot and nodules are red when cut if the plant is growing.

Key Characters:

9-13 leaflets.
Racemes pedunculate.
Pedicels 2-4 mm long.
Blue whorled flowers with a yellow white blotch on the standard petal.
Rough seeds, 6-9 mm long.
Stem hairs to 1 mm long.

Biology:

Life cycle:

Annual. Seed germinates in autumn. It grows through winter and flowers from August to November. The plant dies with the onset of summer drought.

Physiology:

Fixes nitrogen.

Reproduction:

By seed.

Flowering times:

August to November in Perth.
Spring in WA.

Seed Biology and Germination:

Has some dormant seed.

Vegetative Propagules:

None.

Hybrids:

Allelopathy:

Population Dynamics and Dispersal:

The initial spread was from intentional planting.

Origin and History:

Mediterranean and South Western Europe.

Distribution:

NSW, SA, WA.

Courtesy Australia's Virtual Herbarium.

Habitats:

Is most successful on the poorer and lighter soil types.

Climate:

Temperate. Mediterranean.

Soil:

Most abundant on light sandy soils.

Plant Associations:

Heath.

Significance:

Beneficial:

Ornamental.
Grain legume crop.
Fodder. Seedlings are palatable but the mature green plant is normally ignored by stock. Seeds are eaten in summer and some stubble may be consumed as roughage.
Green manure crop.

Detrimental:

Weed of roadsides, crops, wood lands, heath and disturbed areas.

Toxicity:

Three types of toxicity;
1) Lupinosis due to phomopsin produced by an associated fungus, Phomopsis leptostromiformis and results in liver damage. It occurs when stubbles or hay are grazed and may result in heavy stock losses.
2) Lupine poisoning is due to alkaloids in the plant and especially the seeds. It occurs when large quantities of the seed are consumed. Cattle sometimes suddenly die after eating green pods.
3) Some species in North America cause birth defects in cattle but this has not been recorded in Australia.

Symptoms:

Lupine poisoning symptoms are usually seen after driving and include, frothing at the mouth, falling on one side, teeth grinding, laboured breathing and convulsions. If left to rest they usually recover.
Lupinosis symptoms include lethargy, loss of appetite and condition, jaundice, photo sensitisation, loss or directional sense and death. Once symptoms are evident they rarely make a full recovery and may linger for months before death.

Treatment:

Remove stock from lupin areas. Avoid grazing stubbles or feeding large quantities of seed.
No economic treatment.

Legislation:

None.

Management and Control:

Seedlings are susceptible to cultivation and grazing. Germinations may occur after planting crops and a number of selective herbicides provide good control.

Thresholds:

1 plant/m2 is usually worth controlling in cereals to reduce contamination of grain.

Eradication strategies:

Prevent seed set for 3-4 years by mowing, grazing, cultivating, spraying or hand pulling before flowering.
Small areas can be treated with 20 mL of Tordon®75-D in 10 L of water in early winter. This will kill existing plants and leave a soil residual which controls Lupin and other broad-leaved seedlings for about a year. Larger areas can be treated with more selective herbicides such as 200 g/ha Lontrel®750 or 50 g/ha Logran®. The latter two treatments are relatively selective in bushland. For hand spraying mix 25 mL wetting agent plus 4 g Lontrel®750 or 1 g Logran® in 10 L of water. Metsulfuron(600g/kg) at 10 g/ha provides good control but is less selective. Glyphosate is relatively ineffective. Grazing by native animals usually keeps Lupins under control in healthy bushland.

Herbicide resistance:

Biological Control:

Related plants:

Narrow-leaved Lupin (Lupinus angustifolius)
Pearl Lupin (Lupinus mutabilis)
Tree Lupin (Lupinus arboreus)
White Lupin (Lupinus albus)
Yellow Lupin (Lupinus luteus)
Lupinus pilosus
Lupinus polyphyllus cv. Russell hybrid is naturalised in NSW, Victoria and New Zealand and has long sprays of brightly coloured flowers.

Plants of similar appearance:

References:

Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney). P469. Plate

Gardner, G.A. and Bennetts, H.W. (1956). The toxic plants of Western Australia. (West Australian Newspapers Ltd, Perth). P99-104. Diagram.

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). P152. 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). #768.4.

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). P281.

Acknowledgments:

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