Ontario hawthorns (Rosaceae, Crataegus L.) present field botanists with a challenge: they look almost alike, and making
an identification usually requires information from both flowering and fruiting specimens. This workshop places the Ontario species of Crataegus in the context of the genus as a whole, and suggests what features need to be examined in order to be able
to make an identification using the just-published treatment of the genus in Flora North America (Phipps 2015). Instructors:
Timothy Dickinson, senior curator emeritus, Royal Ontario Museum Green Plant Herbarium, and Nadia Talent, research
associate, Royal Ontario Museum Green Plant Herbarium.

Fee: $275 (RBG members: $250; Students: $200)
MAXIMUM 20.
PRE-REGISTER BY MAY 24.