Agric IV is described as a fungal moon due to fungi being the dominant life forms. Fungi and Ferns make up 82% of the Flora and only very simple animals are found in the huge mushroom forests.
Geological and Atmospheric History
The makeup of Agric IV is very similar to Earth although less soil erosion occurs due to the virgin status of the planet. In addition Iridium can be found in large quantities suggesting regular meteorite strikes or volcanic activity. The atmosphere is quite moist and can support the plants even if there is no rain for years. Although the fungi don't photosynthesise Lichen trees which are the largest plant species on the planet produce large quantities of oxygen. Visitors have to be careful as all the spores in the air can cause diseases if inhaled in quantaty.
Discovery and Use
Agric IV has long been used by the Kig-yar to train mercenaries as it is considered a hostile world due to atmospheric and seismic hazards. The Kig-yar would split into two teams and fight each other to reach a certain point with whatever they found on the planet. It would later serve as a meeting point between the Eayn Liberation Front and UNSC to forge an alliance aid to Eayn and defeat the Covenant Remnant.
The Eayn Liberation Front would chose Agric IV to meet the UNSC knowing that it's hostility would drive away anybody following either party. Unfortunately Lepidus would send his son Emberus along with several squads of Brute Hazmat Troopers to deal with the traitors. The battle was bloody and prolonged with each side loosing large numbers of troops.
The Planet is named after the Fly Agric Mushroom (Amanita muscaria) which is known to release large quantities of spores.
The Planet is also meant to represent the Earth's atmosphere and biosphere during the Carboniferous Period which had large quantities of Atmospheric Oxygen