B. chrysostoma is a small annual plant which can be brought into flower 19 days after germination. It is a long-day plant, provided it is grown below 25[degree] C and at an intensity above 150 f.c. At least 5 long photoperiods are required for flower initiation, and a 15-hr. photoperiod is effective. The same thing is true for Phacelia parryi. Baeria plants become photo-periodically sensitive 5 days after germination, and flower initiation can be observed microscopically a few days after treatment with long photoperiods. The intensity of the supplementary light in addition to an 8-hr. photoperiod is above 100 f.c. Both the short and long wavelengths are effective, but green light acts like darkness. No extracts or pure substances induced flowering in plants kept on short photoperiods.