flax rust fungus(n = noun.plant) flax rust, melampsora lini - fungus causing flax rust;
is a kind of rust, rust fungus
is a member of genus melampsora, melampsora

apple rust, ascomycetous fungus, beefsteak fungus, bird's-nest fungus, black root rot fungus, blister rust, blue mold fungus, bottom rot fungus, bracket fungus, brown root rot fungus, carrion fungus, cedar-apple rust, club fungus, clubroot fungus, coffee fungus, coral fungus, cup fungus, damping off fungus, devil's flax, dutch elm fungus, ear fungus, earth flax, face fungus, felt fungus, flag smut fungus, flax, flax family, flax rust, fly fungus, fungus, fungus family, fungus genus, fungus gnat, fungus kingdom, fungus order, gill fungus, green smut fungus, honey fungus, jack-o-lantern fungus, jelly fungus, leak fungus, orange peel fungus, oyster fungus, pink disease fungus, pore fungus, potato fungus, potato wart fungus, ring rot fungus, ring-stalked fungus, rust, rust fungus, rust inhibitor, rust mite, sac fungus, shelf fungus, shoestring fungus, smut fungus, tooth fungus, true fungus, urn fungus, wheat rust, white fungus, white pine blister rust, white rust, white-pine rust, yellow spot fungus