This is the publisher's version, also available electronically from: http://www.jstor.org/stable/10.2307/2474765.The correlation between succulence and Crassulacean acid metabolism (CAM) was investigated in 28
succulent species growing in various habitats throughout North Carolina. Three species (Opuntia compressa^
Agave virginica, and Tillandsia usneoides) exhibited diurnal fluctuations in tissue titratable acidity,
nighttime uptake of 1 4C02 , and a high carbon isotope ratio (513C), all indicators of CAM. Seven species
displayed one or two characteristics of CAM in situ yet yielded lower 513C values, indicating a partial or
total restriction of atmospheric CO2 uptake to the C3 photosynthetic system: Yucca gloriosa, Sesuvium
maritimum, Talinum terettfolium, Diamorpha smallii, Sedum pusillum, Sedum nevii, and Sedum telephioides.
Several of these species were apparently capable of utilizing the CAM pathway to fix internal respiratory
CO2. The results emphasize that one photosynthetic pathway does not characterize all succulents in North
Carolina
