Malacothamnus fasciculatus var. laxiflorus was lumped into var. fasciculatus in some treatments. The most recent research gives phylogenetic, morphological, and geographic evidence supporting recognition of both, though there is a zone of intergradation between the varieties near the border of San Diego and Orange counties in CA. The most recent treatment and POWO recognize var. laxiflorus, so it is split off of var. fasciculatus.