 Occasionally, monokaryons of some taxa can form morphologically fully formed basidiomes and anatomically correct basidia and ballistic basidiospores in the absence of dikaryon formation, diploid nuclei, and meiosis.A rare few number of taxa have extended diploid lifecycles, but can be common species.Examples exist in the mushroom genera "Armillaria" and "Xerula", both in the Physalacriaceae.