CSSA VOL.84, July-August 2012 No.4 CSSA Tour 2010: the Botanical Riches of Oaxaca Dan Mahr Mammillarias of Oaxaca Rick Gillman Guiengola softly in the Footsteps of Thomas Macdougall Catherine Phillips On the Trail of Oaxaca's Great Cacti David A.Yetman On the cover The CSSA caravan stopped along the Mexican Federal Hwy 182 between Teotitlan and Huautla de Jimenez to see Dioon califanoi. It was a short, steep scramble up an eroded road-cut. There were wonderful old specimens of D. califonoi, and some, such as this one, photographed by Karen Zimmerman, were decorated with Mamillaria flavicentra growing epiphytically on their trunks, along with Echeverio nodulosa, tillandsias and lichens.