sentences:  The taxonomic dichotomy is especially interesting in this group of symbionts, because vegetative propagation of fungal mycelium occurs by vertical transmission, i.e., fungal growth into newly developing host tillers (=individual grass plants).Importantly, many "Epichloë" species infect new grass plants solely by growing into the seeds of their grass hosts, and infecting the growing seedling.Manifestation of the sexual state — which only occurs in "Epichloë" species — causes "choke disease", a condition in which grass inflorescences are engulfed by rapid fungal outgrowth forming a stroma.