Proteoid Roots
Plant species which develop proteoid roots usually lack mycorrhizae,
and unlike mycorrhizal or nodulated roots there is no microbial or fungal associate.
However, there is evidence that their formation may be microbially triggered.
Proteoid root development is greatest in the upper soil horizons, particularly on infertile soils where they can form a thick mat at the interface between the litter and mineral soil horizons.
The litter layer of a Banksia integrifolia woodland, showing proteoid roots (the feathery white structures) proliferating amongst the partially decomposed leaf litter.