Quena

Solanum esuriale Lindley

Family: Solanaceae.

Names:

Solanum comes from the Latin solamen meaning to quieten or comfort and refers to the narcotic properties of some species.
Quena

Other names:

Comyn
Oondoroo
Potato Bush
Potato Weed
Tomato Plant
Tomato Weed
Wild Tomato

Summary:

An erect sparsely branched, grey, velvety, hairy perennial plant with 5 petalled purple flowers from March to July and yellow berries.

Description:

See the Weedy Solanum Key.

Cotyledons:

Two. Lance shaped, long and narrow with a pointed tip and a merging base. The petiole is about two thirds the length of the blade. Hairless.

First Leaves:

Oval with a pointed tip and fine hairs. Petiolate.

Leaves:

Alternate.
Petiole - Yes.
Blade - Oblong, oval or lance shaped, 20-50 mm long, 4-20 mm wide. Tip rounded, flat indented or pointed. Smooth edges or slightly lobed and often wavy. Surface undulating. Somewhat folded along the midrib. Greyish to yellowish-green due to dense star type hairs.

Stems:

Erect or bent over, slender, 60-300 mm tall, greyish to yellowish-green with close velvety star type hairs. May have a few, small, straight, prickles on the branches or near the base. Often single stemmed or with a few branches.

Flower head:

Cyme with 1-6 flowers in the upper leaf axils. On a common, sometimes long, stalk (peduncle) and flowers may be on a stalk (pedicel) also.

Flowers:

Purple or occasionally white.
Ovary -
Calyx - 5 mm long with 5 spreading tapering lobes. Become enlarged and bent back when in fruit with triangular lobes.
Petals - Purple occasionally white. 10-20 mm long. Hairy on the outside. 5 lobed arranged like spokes on a wheel and split almost to the base.
Stamens - Very short filaments.
Anthers - Yellow, longer than the filaments, parallel sided, converging at the tips, protruding from the flower, opening at the top by 2 pores.

Fruit:

Yellow, globular or egg shaped, soft, juicy berry. 10-15 mm diameter, 2 celled.

Seeds:

Flattened. 3 mm diameter.

Roots:

Extensive, creeping root system.

Key Characters:

Leaves 25-50 mm long, longer than broad, lanceolate-oblong to linear-lanceolate undulate margins, thin in texture with dense stellate tomentum on both faces, green when fresh, drying whiter below, few prickles or absent. Velvety tomentum on both surfaces
Branches with stellate hairs and usually with prickles.
Flowers few to several in simple cymes.
Calyx with no prickles, lobes acute
Berry yellow, 10-15 mm diameter.
Herbs or shrubs
Adapted from J.M. Black.

Biology:

Life cycle:

Perennial. Flowers most of the year. Seeds germinate in summer. Growth from roots occurs throughout the year.

Physiology:

Reproduction:

By seed.

Flowering times:

March to July in WA.
Most of the year in western NSW.
Most of the year in SA.

Seed Biology and Germination:

Vegetative Propagules:

None.

Hybrids:

Allelopathy:

Population Dynamics and Dispersal:

May occur as scattered plants but often in small dense patches.
Often abundant after drought or heavy grazing that leaves the soil bare.

Origin and History:

Native to Australia.

Distribution:

NSW, NT, QLD, SA, VIC, WA.

Courtesy Australia's Virtual Herbarium.

Habitats:

Low lying areas.

Climate:

Temperate.

Soil:

Usually on loam and clay soils.

Plant Associations:

In many communities.

Significance:

Beneficial:

Berries are eaten by Aboriginals.

Detrimental:

Not very palatable to stock but sheep may eat the berries.
Weed of fallows, native grass lands.

Toxicity:

May cause "humpy back" syndrome in full wool sheep especially wethers in hot conditions.
Toxicity probably due to alkaloids. It also may accumulate toxic levels of nitrates. May be toxic to sheep and cattle.

Symptoms:

Humped back posture. Tire quickly. Often die if driven too hard.
Alkaloid poisoning.
Nitrate poisoning.

Treatment:

Remove stock from infestation.
Truck humpy back sheep to shed for shearing and allow to rest
Alkaloid poisoning.
Nitrate poisoning.

Legislation:

None.

Management and Control:

Thresholds:

Eradication strategies:

Prevent seed set. Exclude stock from plants with seed.
Treat small areas with Tordon® 75-D annually.

Herbicide resistance:

Biological Control:

Related plants:

See the Weedy Solanum Key.
Afghan Thistle (Solanum hoplopetalum)
Apple-of-Sodom (Solanum hermannii or Solanum linnaeanum)
Bittersweet (Solanum dulcamara)
Blackberry Nightshade (Solanum nigrum)
Brazilian Nightshade (Solanum seaforthianum)
Buffalo Burr (Solanum rostratum)
Desert Nightshade (Solanum oligacanthum)
Devils Apple (Solanum capsicoides)
Devils Fig (Solanum torvum)
Devils Needles (Solanum stelligerum)
Eggplant (Solanum melongena)
Flannel bush (Solanum lasiophyllum)
Giant Devils Fig (Solanum hispidum)
Glossy Nightshade (Solanum americanum)
Goosefoot Potato bush (Solanum chenopodinum)
Green-berry Nightshade (Solanum opacum)
Kangaroo Apple (Solanum aviculare)
Kangaroo Apple (Solanum laciniatum)
Kangaroo Apple (Solanum vescum)
Madeira Winter Cherry (Solanum pseudocapsicum)
Menindee Nightshade (Solanum karense)
Narrawa Burr (Solanum cinereum)
Oondooroo (Solanum simile)
Porcupine Solanum (Solanum hystrix)
Potato bush (Solanum ellipticum)
Potato climber (Solanum jasminoides)
Potato tree (Solanum erianthum)
Potato (Solanum tuberosum)
Rock Nightshade (Solanum petrophilum)
Silver-leaved Nightshade (Solanum elaeagnifolium) is similar but has longer thinner anthers, prickles on the mid rib on the back of the leaf, stiffer stems and more deeply lobed leaves.
Thargomindah Nightshade (Solanum sturtianum)
Three flowered Nightshade (Solanum triflorum)
Tomato bush (Solanum quadriloculatum)
Western Nightshade (Solanum coactiliferum)
White-edged Nightshade (Solanum marginatum)
Wild Tobacco tree (Solanum mauritianum)
Woolly Nightshade (Solanum villosum)
Solanum arbutiloides
Solanum centrale
Solanum chippendalei
Solanum dimidiatum
Solanum dioicum
Solanum oldfieldii
Solanum orbiculatum
Solanum papaverifolium
Solanum sisymbriifolium

Plants of similar appearance:

References:

Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P229. Photo.

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P747.

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P590. Photo.

Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney). P662. Plate 46.

Gardner, G.A. and Bennetts, H.W. (1956). The toxic plants of Western Australia. (West Australian Newspapers Ltd, Perth). P165.

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). #1140.17.

McBarron, E.J. (1983). Poisonous plants. (Inkata Press, Melbourne). P91. Diagram.

Wilding, J.L. et al. (1987). Crop weeds. (Inkata Press, Melbourne). P147. Diagrams. Photos.

Acknowledgments:

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