Leafy growth form
Plants retain flat, fleshy leaf blades on elongated shoots. The presence of areoles and glochids links them to Opuntioideae. Leaf similarity to Pereskia is readily visible, while phylogenomics places Pereskiopsis in Cylindropuntieae within the opuntioids. [Martin and Wallace 2000] [Majure et al. 2019]
Variation in metabolism
Martin and Wallace studied P. aquosa, P. diguetii, P. porteri and material identified as P. gatesii (now a synonym of P. porteri). Leafy shoots took up CO₂ by day and night, with different contributions from the two phases. Acidity increased at night in leaves and stems, partly through refixation of CO₂ released in respiration. Retaining the publication's separate samples also allows variation within today's species treatment to be followed. [Martin and Wallace 2000] [2-WWW]
Drought changes the timing of assimilation
An experiment with P. porteri showed rapid inhibition of daytime assimilation during drought and an increase in the relative importance of nocturnal uptake. This transition occurred as total daily carbon input declined. Long-lived leaves are thus an active component in regulation of water and carbon management. [Nobel and Hartsock 1987]
Names in collections
POWO accepts six species in the genus. Among older names, P. spathulata and P. velutina are synonyms of P. diguetii, and P. gatesii of P. porteri. Research accounts retain the source name in parentheses beside the accepted name. [2-WWW]