Do all plants have roots?
There are no roots in a special already outdated botanical taxon of plants - Inferior. It includes various algae. Both unicellular and multicellular. The body of these plants is not divided into any parts - roots, stem, leaves. Their entire body is a homogeneous mass, which has a special name - thallus or thallus. Sometimes some species of green and brown algae have special body processes that resemble roots (but are not roots) - these are rhizoids.
There are two groups of plants that do not belong to the Inferior, but have rhizoids (not roots) - some types of mosses and Psilota. This is a group of higher plants, but they are an exception.
All other plants belong to the outdated group - Higher. They are distinguished by the fact that their body has all three parts: roots, stem, leaf. Another thing is that these parts can be modified or reduced.
I heard for sure that green algae do not have roots, they just float on the surface of the water, and seaweed also has no roots, they cling to the seabed with the help of peculiar fastening ends.
In lower plants - algae - it is impossible to isolate roots, stem and leaves in the body of plants. Therefore, not all plants have roots. Higher plants have roots: flowering and conifers.