Xylaria is a large (at least 400 names and ultimately 500 or more species) widely distributed fungal genus (Family Xylariaceae, Order Sphaeriales, Subdivision Ascomycotina). Many taxa occur on wood, seeds and fruits, and leaves of angiospermous plants; some taxa are associated with insect nests. Most taxa decay wood and a large number are plant pathogens. They are common endophytes. Xylaria and its allies are most numerous in the tropics where they form a conspicuous part of the mycota. Many taxa are endemic and likely to become extinct as hosts are destroyed. Mycofloristic studies that include cultural, anamorphic, cytological, structural, and life history data are proposed. It is proposed herein: to continue studies of Xylaria from the Guianas; to treat Xylaria and its allies from Taiwan; to complete treatments of Xylaria from continental United States, Hawaii, and Puerto Rico. Longer term objectives include a treatment of Xylaria of the neotropics and, eventually, a world monograph.