Opium Poppy

Papaver somniferum L. ssp. somniferum and Papaver somniferum ssp. setigerum.

Synonyms - Papaver setigerum.

Family: Papaveraceae

Names:

Papaver is Latin for Poppy.
Somniferum is from the Latin somnus meaning sleep and fero meaning to bring and refers to the coma inducing properties of the plant extracts.
Opium Poppy refers to the opium collected from the buds and it membership of the Poppy family.

Other Names:

Cultivated Opium Poppy (Papaver somniferum ssp. somniferum).
Small-flowered Opium Poppy (Papaver somniferum ssp. setigerum).
Small Opium Poppy (Papaver somniferum ssp. setigerum).
Wild Poppy (Papaver somniferum ssp. setigerum).

Summary:

Oil-seed Poppy. The mature plant is erect in habit with stems which may be branched and reaches a height of 1.4 m and is an annual. In cultivation this species is very variable in height depending on the fertility status of the soil and the time of year when it germinated, and when it occurs as a weed it shows a similar wide range in size. The leaves clasp the stem, are blue-green, crinkled on the edges and toothed and with a bristle at the tip. The flowers are white, pink or purple and usually have a dark blotch at the base of each petal. They have 4 petals and some varieties appear to have more. The fruiting capsule is large, smooth and globular and exudes a white sap like the stems and leaves when injured.

Description:

Cotyledons:

Two. The cotyledon is stalkless, 10 to 15 mm long, narrow and hairless. The tip is pointed. Edges smooth. Base tapered. The seedling has a hypocotyl but no epicotyl.

First Leaves:

The first two leaves appear as a pair, but subsequent leaves grow singly. The first leaves are oval, 8 to 15 mm long overall of which rather less than half is petiole. The first two leaves have simple margins and the next 2 to 3 have small lobes. Later leaves have lobes which become larger and more numerous. Tip pointed. Edges smooth to toothed. Base tapering. Surface frosted appearance, often dull blue green, with hairs on the upper side. Petiole also has hairs.

Leaves:

Alternate. Forms a rosette which tends to have the leaves semi-erect rather than flat. Milky sap.
Petiole - None.
Blade - Egg shaped to oblong, 40-180 mm long, blue-green, tapers to a stalk like stem clasping base, slightly lobed with sharp, irregular teeth that have a bristle at the tip. A few long hairs on the upper and lower surface and more on the margin. Tip pointed. Edges toothed. Base tapered to indented.
Stem leaves - 30 to 150 mm long, narrowly egg shaped, shallow lobes, stem clasping and hairless. Towards the top of the stem the leaves are smaller.

Stems:

Erect, up to 1400 mm tall, hollow or solid and pithy, stout, blue-grey with a waxy bloom, fluted in cross section. May be branched. Hairless or have only a few stiff hairs in some cultivars. Milky sap. The stems often droop after flowering.

Flower head:

Single flower on the ends of stems on a long stalk (peduncle) that is hairless or with stiff bristles.

Flowers:

Light purple or pink or white, 40 to 100 mm in diameter.
Ovary - Rounded. No style.
Sepals - 2, concave, overlapping, fall off as the flower opens.
Petals - 4, overlapping, white, pink or light purple and usually have a darker basal blotch. Obtuse tip.
Stamens - Many. Thickened upwards.
Anthers -

Fruit:

Blue-green capsule, more or less spherical, 10 to 50 mm in diameter with a flat plate-like stigmatic disk on top. Borne on a long stalk. Stigmatic disk has 8-15 rays. Hairless. Capsule does not open at maturity to release seed in cultivated forms. In naturalised forms seeds are released through pores at the top of the capsule below the stigmatic disk. Exudes milky sap when damaged.

Seeds:

Many, grey-brown, blue-grey to black, tiny, less than 1 mm diameter and kidney shaped. The surface is ridged, hairless and has a network or honeycomb like pattern on the surface.

Roots:

Shallow, branched taproot with many branched side roots.

Key Characters:

Leaves clasp the stem. Capsule hairless and sub globular. Petals pink, light purple or white with a conspicuous dark spot at the base. Filaments thickened upwards.
Ssp setigerum has is smaller in height, flower size and capsule size than ssp. somniferum.

Biology:

Life cycle:

Annual. The main germination occurs in autumn and early winter with a minor germination in spring in some areas. A rosette forms over winter and stems emerge in spring ready for flowering From October to December. Seed ripens in summer and the plants die with the onset of summer drought or in autumn.

Physiology:

Chromosome number n=11.

Reproduction:

By seed.

Flowering times:

Summer in western NSW.
Summer in SA.
Spring in WA.

Seed Biology and Germination:

Seed remains viable in the soil for a number of years.

Vegetative Propagules:

None.

Hybrids:

Sub species somniferum has smooth hairless stems, leaves with wavy and toothed but not lobed edges, 75-100 mm diameter flowers, 8-12 stigmatic rays on the disk on top of the capsule, 40-70 mm long sub globular fruit, tends to hold its seed in the capsule, smooth hairless peduncles and a chromosome number of n=11.
Sub species setigerum has scattered bristly hairs near the top of the stem, leaves with bristled tipped irregular lobes with wavy and irregularly toothed edges, 40-50 mm diameter flowers, 5-9 stigmatic rays, 15-60 mm long x 15-40 mm wide elongated globular fruit, releases its seed from the capsule when ripe, bristly peduncles and a chromosome number of n=22.
Double flowered forms are grown as ornamentals and often recognised as a variety P. somniferum var. paeoniflorum. These forms don't produce significant opiates.

Allelopathy:

Population Dynamics and Dispersal:

Spread by seed. Most seed falls close the parent plant. Some is spread by flowing water, mud and soil being moved by animals or machinery, and some by wind.
Intentional planting for ornamental or other purposes accounts for most long distance spread.
Most infestations are ssp. setigerum. Some infestations are a mixture of the two sub species with the opium producing ssp. somniferum being the minor component of the infestation. This is probably because ssp. somniferum doesn't release its seed from the capsule readily.

Origin and History:

Asia. Europe. Mediterranean.
Introduced to Australia during the gold rushes probably by Chinese miners.

Distribution:

NSW, QLD for ssp. somniferum.
ACT, NSW, NT, QLD, SA, TAS, VIC, WA for ssp. setigerum.
Opium Poppy is grown in the North-West, and in parts of the North-East, Midlands, and South of Tasmania.
Variants of Opium Poppy are common in gardens but they are rarely the ones yielding the opium drug.
The cultivar yielding opium has not been found in WA outside of illegal cultivation.

Courtesy Australia's Virtual Herbarium.

Habitats:

Climate:

Warm temperate. Sub tropical montane.

Soil:

Wide range.

Plant Associations:

Significance:

Beneficial:

Commercially grown as a source of alkaloids for pharmaceutical purposes.
Poppy seed used as a garnish on bread.
Ornamental.

Detrimental:

Where crops have been grown volunteer seedlings frequently occur in the following and subsequent years as weeds. The growing of Opium Poppy other than as a licensed crop is prohibited under the Dangerous Drugs Act.
It is rarely a significant competitor in cereals.
Weed of roadsides, fallows and disturbed areas.

Toxicity:

Contains alkaloids, opium and morphine in sufficient quantity to be toxic to stock and poultry.
Poisoning is usually associated with animals eating seeds, capsules or fodder contaminated with Poppy plants or residues. In field situations stock rarely eat enough to cause problems because it has an unpleasant taste and odour.
The dried latex from the immature pod is opium which contains morphine and at least 20 other alkaloids including codeine and narcotine. Morphine is addictive, codeine is an analgesic and narcotine is narcotic.

Symptoms:

Gastro enteritis, excitability, Lack of appetite, colic pains loss of muscle control.
Cows become unthrifty, lose weight and stop producing milk.

Legislation:

Noxious weed of NSW and ACT.
In Tasmania, escapes from the commercial crops are controlled by the government.

Management and Control:

Cultivation before flowering is effective.

Thresholds:

Eradication strategies:

Prevent seed set for a number of years until seed bank is exhausted.
Many herbicides provide high levels of control of young plants, but older plants can be difficult to kill.

Herbicide resistance:

Biological Control:

Bio control is being studied.
A root parasitising Broomrape (Orobanche papaveris) and a fungus (Cochliobolus spicifer) commonly attack it in Australia.

Related plants:

Bristle Poppy (Papaver aculeatum)
Field Poppy (Papaver rhoeas)
Long-headed Poppy (Papaver dubium)
Pale Poppy (Papaver argemone)
Rough Poppy (Papaver hybridum)
Small flowered Poppy (Papaver somniferum ssp. setigerum)

Plants of similar appearance:

California Poppy (Eschscholzia californica) has the sepals joined into a pointed hood which is pushed off by the petals.

References:

Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P198-199. Photo.

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P366.

Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P177.

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P314. Photo.

Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney). P568-569.

Gardner, G.A. and Bennetts, H.W. (1956). The toxic plants of Western Australia. (West Australian Newspapers Ltd, Perth). P30.

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). P194.

Hyde-Wyatt, B.H. and Morris, D.I. (1975). Tasmanian weed handbook. (Tasmanian Department of Agriculture, Hobart, Tasmania). P98-99. Diagram.

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). #927.6, 927.7.

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). P68.

Moerkerk, M.R. and Barnett, A.G. (1998). More Crop Weeds. R.G. and F.J. Richardson, Melbourne. P110. Diagrams. Photos.

Parsons, W.T. and Cuthbertson, E.G. (1992). Noxious weeds of Australia. (Inkata Press, Melbourne). P537-539. Photos.

Acknowledgments:

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