Myscellia

Planetary Data
Myscellia quickly became a fungi haven, as this life form was the only one to prosper, elder mushrooms caress the infected clouds of the planet, depositing spores that'll rain for days, below the ground, the entirety of the outer mantle is packed with mycelium. Such victory over an otherwise barren planet, and the lack of motion above the ground gave green light for sentient lifeforms to sprout out of the floor, rudimentary and basic at first, but quickly evolving into an intelligent civilization, the population grew as quickly as they would have done if they stood bound to the floor.

The air is so packed with spores it'd be hard for other species to breath, mushrooms on the surface go from mere centimeters to kilometers up out of the atmosphere, standing on place of what in other planets would be mountains and canyons on what otherwise would be a flat planet.

Inhabitants
Myscellians remain reminiscent to their ancestors, with their large characteristic caps and on the duty of spreading by spewing spores at will from their heads. The inhabitants themselves are far from intrusive or contagious as their brainless relatives might lead you to believe, rather, the gift of discovery kick-started a healthy curiosity for meeting other living organisms and cultures.

Once they managed to get grip on interplanetary travel, they were fond of absorbing the otherwise unknown, things such as animals or plants was something unseen for them until then.