Algal distributions and temperature: test of an hypothesis based on vegetative growth rates by Joan G. Stewart. Bull. Southern California Acad. Sci., 83(2):57-68, 1984. Vegetative growth rates were measured for five species of red algae in response to different water temperatures under laboratory conditions to consider whether the behavior of the plants might help explain the restriction of certain taxa to subtidal habitats off" southern California coasts. The thalli from which cultures were initiated were adult— i.e., of a size characteristic of collected non-juvenile specimens in natural populations. All thalli grew more rapidly at warmer temperatures (16°C or 20°C) than at 12°C indicating that these species are not segregated into colder or warmer habitats by direct effects of temperature on vegetative growth.