Preliminary Study on Floral Syndroma and Breeding System for Five Species of Rehmannia (Scrophulariaceae) Breeding System and Pollina tion Ecology in J a tropha cu rcas Spike Differentiation and Flowering Characteristics in Tall fescue Flowering characteristics and pollination ecology of Scabiosa tschiliensis Flowering characteristics and pollination biology of rare and endangered Kolkwitzia amabilis A Study on Breeding System of the Endangered Plant Cistanche deserticola Flowering Characteristics and Breeding System in Camptotheca acuminata Decne Floral syndrome and breeding system of Erigeron breviscapus Flowering Characteristics and Chemical Control of the Buds of Arceuthobium sichuanense Determination of the wind pollination distances and flowering characteristics of Hippophae rhamnoides L.ssp. sinensis Rousi (Elaeagnaceae)