Phellinus weirii cultures were stored successfully for 10 years in small alder (Alnus rubra Bong.) disks at 2 "C. The six isolates tested appeared morphologically identical and after 10 years varied little in growth rate from those stored on malt agar slants. Long-term storage on alder disks reduces the time required for maintaining cultures and the risk of contamination inherent in frequent transfers necessary in storage on agar slants.