Gold for Plants: Turgor
Gold (= Aurum) (Au)
Gold in plants was first discovered in plant ash by the French chemist Claude Louis Berthollet. Although gold in plants is deposited in the form of nanoparticles – granules with diameters in millionths of a millimeter, some scientists claim that it is quite possible to increase the gold content in plant tissues to 20%.
The presence of a certain amount of gold in plant ash can be an exploratory indicator for geologists (indicator plants).
• red fescue Festuca rubra L., Poaceae (especially – seeds, content – 95.05 mg per 1 ton);
• common corn Zea mays L., Poaceae: from 1 ton of corn waste ash, up to 60 g of gold can be obtained;
• silky phacelia Phacelia sericea (Graham) A. Gray, Hydrophyllaceae.
In brown and red algae growing on gold-bearing fine-grained clayey sands, there is 6–7 times more gold than in algae growing on non-gold-bearing fine-grained clayey sands. Because of this, marine algae can be used for mapping areas prospective for placer gold. This method is valuable because collecting algae from the bottom is not particularly labor-intensive.
Interestingly, gold concentrations in different areas of the World Ocean are far from uniform. While on average, 1 ton of seawater contains 0.02 mg of gold, in the Caribbean Sea, its content reaches 15–18 mg.
Usually, gold in soluble form is toxic to microorganisms and animals. A slight impurity of gold in water, undetectable by sensors, causes a noticeable dilation of blood vessels in frogs.
• gray mustard Erysimum canescens Roth., Brassicaceae (herb);
• alfalfa Medicago sativa L., Fabaceae (herb);
• species of wormwood Artemisia L., Asteraceae (herb);
• intoxicating lagurus Lagochilus inebrians Bunge, Lamiaceae (herb);
• field horsetail Equisetum arvense L., Equisetaceae (herb);
• species of oak Quercus L., Fagaceae (bark);
• silver birch Betula pendula Roth, Betulaceae (buds, leaves);
• common corn Zea mays L., Poaceae (silks);
• species of honeysuckle Lonicera L., Caprifoliaceae (fruits).