- Award to person who has made outstanding contributions to bryology, given at the IAB meeting held in conjunction with each International Botanical Congress (once every six years).
- Award can only be received once.
- Selection Committee chaired by the IAB President who is in office for the two years before the presentation. with three members appointed by the IAB Council at each Botanical Congress.
Yoshinori Asakawa and Geneva Sayre (1983),
Bill Steere (1987),
Riclef Grolle (1999).
Lewis Anderson (2005).
Támas Pócs (2011).