Complex sentence: Arbuscular mycorrhizal fungi are all placed in the phylum (division) Glomeromycota, and form the widespread arbuscular mycorrhiza symbiosis with land plants Embryophyta.
Split into simpler sentences: Arbuscular mycorrhizal fungi are all placed in the phylum (division) Glomeromycota. They form the widespread arbuscular mycorrhiza symbiosis with land plants Embryophyta.