The article presents the program for the annual meeting of the Phycological Society of America at the Arizona State University, Tempe, Arizona. The meeting will be held from June 16-22, 1974. The chairman of the program is Norma J. Lang. A field trip is scheduled on June 15, 1974. Researchers Dean W. Blinn and Gerald W. Prescott will lead the field trip. All sessions of the program at which contributed papers are presented are joint sessions of the Phycological Society of America and the Phycological Section of the Botanical Society of America.
RESEARCH, CACTUS, SUCCULENT plants, PHYSICAL geography, ARID regions
Abstract
The article discusses the cacti species' cold resistance and its geographical distribution. According to the study conducted by the Department of Botany at the University of Arizona in Tucson, Arizona, the geographical distribution of cacti, which are entirely adapted to a dry climate, is mainly dependent on the cold resistance of the species. It also says that not only cold resistance manifest itself for the new species occurring in the northern latitudes of the U.S. and Canada, but it determines the distribution of cacti at the higher altitudes proximity to the southern deserts where they are abundant. Furthermore, various species of cacti are also presented.