1) Clusters of cells on ferns 2) Clusters of spores 3) Clusters on ferns 4) Fern clusters 5) Fern features 6) Fern fruit dots 7) Fern spore-class clusters 8) Fern spores 9) Fruit dots 10) Fruit dots on ferns 11) Fungus structures 12) Plant clusters 13) Spore cases on ferns 14) Spore clusters 15) Spore clusters on ferns Found on https://www.crosswordclues.com/clue/sori