Walnut
Juglans regia L.
Order - Juglandales
Family - Juglandaceae
Names:
Juglans
Regia
Walnut
Other Names:
Summary:
A deciduous, nut tree with golf ball sized, hard shelled nuts.
Description:
Cotyledons:
Two.
Leaves:
Stipules -
Petiole -
Blade -
Stems:
Flower head:
Flowers:
Ovary -
Sepals -
Petals -
Stamens -
Anthers -
Fruit:
A hard shelled nut.
Seeds:
Dry pulp.
Roots:
Key Characters:
Biology:
Life cycle:
Perennial tree. Trees are shaken or nuts knocked down when ripe then dried and usually bleached before sale.
Physiology:
Sensitive to early spring frost.
Sensitive to heat scald in summer.
Long chilling requirement.
Reproduction:
Flowering times:
Seed Biology and Germination:
Prefers cross pollination. Catkin bearing trees are wind pollinated.
Vegetative Propagules:
Hybrids:
Allelopathy:
Population Dynamics and Dispersal:
Spread mainly by intentional planting.
Usually grafted to a rootstock.
Origin and History:
South east Europe to China. Between Iran and the Himalayas.
Imported as a nut crop.
Distribution:
ACT, NSW, SA, TAS, VIC, WA.
Habitats:
Climate:
Temperate. Mediterranean. Cool temperate.
Requires more than 760 mm rainfall annually or irrigation.
Soil:
Deep, friable well drained soils.
Prefers soils with high organic matter.
Often grown in river valleys.
Plant Associations:
Significance:
Beneficial:
Edible nuts.
Detrimental:
Toxicity:
Not recorded as toxic.
Legislation:
None.
Management and Control:
Thresholds:
Eradication strategies:
Chain saw.
Herbicide resistance:
Biological Control:
Pests include Codling Moth, Erinose Mite, Birds and Rabbits.
Diseases include Bacterial Blight, Phytophthora root rot and Armillariella root rot.
Related plants:
Black Walnut (Juglans nigra)
Plants of similar appearance:
References:
Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). #702.2.
Reid, R.L. (1990) The Manual of Australian Agriculture. (Butterworths, Sydney). P192.
Acknowledgments:
Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.