 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 20 cm ( 8 in ) 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 . 
