Most of the subspecies are found from southern Queensland through to Victoria but subspecies longifolium is found in north eastern Queensland. The individual cream to pale yellow flowers are five-petalled and relatively small but they occur in clusters of a dozen or more together and are very conspicuous. Flowering usually occurs in early spring. P.squamulosum is the most commonly cultivated member of the genus and a number of forms have proven reliable under garden conditions in temperate and sub-tropical climates. In common with most members of the Rutaceae, propagation of P.squamulosum from seed is difficult.
Cuttings usually strike readily from current season's growth.
Some experimentation has been carried out into using P.squamulosum as a root stock for grafting of some of the more difficult to grow species such as P.nottii . You may have reached this description from one of several different sources.