(N/A) $\rightarrow$ Mycorrhiza: Roots in some genera have a fungal association known as Mycorrhiza (Mycos = fungi,Rize = roots).
$\rightarrow$ Fungi form a colony either outside or inside the cells of the host plant. They help in the absorption of nutrients from the soil. This association is commonly seen in conifers like $Pinus$,$Cedrus$,$Abies$,and $Picea$.
$\rightarrow$ Coralloid Roots: These are observed in $Cycas$. They arise from the basal part of the plant and grow upwards from the soil. They are branched and greenish in color. $A$ colony of blue-green algae,such as $Anabaena$ and $Nostoc$,is found in their cortex,which maintains a symbiotic relationship with the coralloid roots.