(A) Switchgrass root hair growth promotion in the presence of the dark septate endophyte (DSE) fungus, cidomelania panicicola. Warm season C4 grasses such as switchgrass rely on their symbiome to persist in stressful environments such as the Pine Barrens of New Jersey, USA.
(B) Symbiosis between the water fern Azolla and the cyanobacterium
Anabaena that involves vertical inheritance of the cyanobacterium via the mega-spore apparatus of the water fern. This is a transverse section of the megaspore apparatus that shows the
megaspore (m), the floats (f), and the cyanobacteria (c; red region at the top of the megaspore apparatus).
(C) Examples of the obligate lichen symbiosis. Top two rows show examples of lichen species present in the southern Appalachian Mountains. The lower row shows light micrographs of different types of algal associations (indicated with
arrows, from L to R: Trebouxia, Trentepohlia, Nostoc) in lichen thalli.