At the arboretum. For information, email Brett Hall at brett@ucsc.edu. Focus seems like it's going to be on rare and endangered species, many Southern Hemisphere and New Caledonian ones, with presentations by collectors and botanists who specialize in these fields. Starts around 6 p.m.
Bit too far away, unfortunately :-( With endangered species on the topic, I hope they'll be covering the now highly endangered Santa Cruz Cypress Cupressus abramsiana, much reduced in population after recent fires.
Speaking of that species, is there any ex-situ conservation going on to help preserve it, and where exactly can it be found? How many trees did the fire take out?
There is some ex-situ conservation, e.g. some planted at the Arboretum de Villardebelle in southern France. Here's a map showing the locations, pre-fires. At least some survived the Bonny Doon fires ( http://www.pinetum.org/JeffCUabramsiana.htm scroll down to 'Bonny Doon' section), and there may well be regeneration from cones on the burnt trees too. The problem for the future is increased fire frequency due to human activity - if the next fire comes along before the regrowth is mature, the population becomes extinct.