Fig. 3. The effect of temperature on the rate of respiration (A) and photosynthesis (B) in a turlough (Lough Gealáin) and ruderal (Dodder) population of Ranunculus repens. Leaf segments of known area were submerged in artificially hardened water and oxygen evolution was measured using an oxygen electrode under saturating light conditions. Plants were grown from seed. Values are means of four replicates and bars represent s.e.m.