Cardinal temperatures for seed of C. gynandra and S. retroflexum could not be estimated due to poor germination and emergence. However, it appears as though seed germination for C. gynandra, although greater than 50% percentage germination was only attained at 28 °C (65%), 32 °C (75.5%) and 36 °C (56.5%) could be favourable at 31 °C. Compared to Böhringer et al. (1999), the germination of C. gynandra seed observed in this study was in fact more complete. This could be due to the seed lots used in the current study had been in storage for a longer period, favouring immature embryos to reach maturity, than those used by Böhringer et al. (1999), which were only 6 months old ( Ochuodho and Modi, 2005 and Ekpong, 2009).