Curator Emeritus at The New York Botanical Garden, Bronx. Adjunct Researcher at Denver Botanic Gardens, Colorado.

Interested generally in mushroom systematics and mycogeography with particular focus on Boletes. Websites are located at: http://sweetgum.nybg.org/boletineae/index.php (BOLETINEAE). http://www.nybg.org/bsci/res/hall (MACROFUNGI COSTA RICA). http://www.nybg.org/bsci/res/col (COLLYBIA s.l.).