The development of the ovule and macrogametophyte in Monarda fistulosa, M. didyma, M. punctata, and Nepeta cataria is very similar. The ovule is anatropous, has a single massive integument, a one-layered nucellus which degenerates early, and an integumentary "tapetum." In all spp. a hypostase is formed, and in all but N. cataria an obturator is developed. The chalazal macrospore is always the functional one and the gametophyte is of the 7-celled type. The spp. differ with regard to the time at which the integument completely surrounds the nucellus, the thickness of the integument, the rate of nucellar degeneration, the length of micropyle, size of macrospores, and the prominence of the hypostase.