Figure 12.5 Cotyledon orbiculata grown for 20 weeks under high light (1,300 µmol quanta m^-2 s^-1, left) or low light (350 µmol quanta m^-2 s^-1, right) in controlled growth chambers. Scale bar = 10 cm. (S.A. Robinson et al., Bot Acta 106: 307-312, 1993; photograph courtesy S.A. Robinson)