The other common adaptation is the possession of cluster roots, which allow it to extract enough nutrients to survive in the oligotrophic soils in which it grows. With the onset of autumn rains, the lateral roots form dense surface mats of cluster roots in the top of soil, just below the leaf litter, where most minerals are concentrated. These roots exude chemicals that enhance mineral solubility, greatly increasing the availability and uptake of nutrients in impoverished soils such as the phosphorus-deficient native soils of Australia. For as long as surface water is available, they take in water and a range of minerals. In "B. prionotes" they are principally responsible for the uptake of malate, phosphate, chloride, sodium and potassium. When soils are high in nitrates, they may also perform some nitrate reductase activities, primarily the conversion of ammonium into amino acids such as asparagine and glutamine.