Structure and name
The currently accepted name is Pereskiopsis aquosa (F.A.C.Weber) Britton & Rose. Material studied by Martin and Wallace had persistent, small, flat, fleshy leaves and thick, hard shoots. This structure allows leaf and stem functions to be measured separately. [2-WWW] [Martin and Wallace 2000]
Carbon uptake by two organs
At 30/20°C under a fourteen-hour day, leafy shoots took up CO₂ both by day and at night, with daytime assimilation predominating. Green stems showed a positive balance in both phases. The daytime curve for leafy shoots declined around midday, as in the other Pereskiopsis studied. [Martin and Wallace 2000]
Organic acids and CO₂ recycling
Nocturnal CO₂ uptake was accompanied by increasing acidity in leaves and stems. Some of this increase resulted from refixation of CO₂ produced within the plant. In the stem studied, the contribution of an internal carbon source to the nocturnal acid increase was significant despite continued exchange with the atmosphere. The result documents continuity between daytime photosynthesis, CAM and respiratory recycling within one organism. [Martin and Wallace 2000]
Synonyms and names in the literature
Grusonia aquosa · Opuntia aquosa [2-WWW]