Cluster roots are common in daviesia and allies (Mirbelioids; fabaceae)

Cluster roots are best known in the Proteaceae, but also occur in other plant families. Cluster roots are produced by Viminaria juncea and some species of Daviesia, which belong to the Australian Mirbelioids (Fabaceae). We searched for cluster roots in a number of species in Daviesia and its close allies Gompholobium and Sphaerolobium and found them in all studied species of these three genera. Daviesia incrassata subsp. incrassata, collected at an unusually waterlogged habitat, had no cluster roots, but they were present in D. incrassata subsp. reversifolia in a drier habitat. Cluster roots are pervasive in the Daviesia group of the Fabaceae, allowing them to persist on low-phosphorus soils.