POLLINATION ECOLOGY OF GENTIANA LAWRENCEI VAR. FARRERI, A LATE-FLOWERING QINGHAI-TIBET PLATEAU SPECIES Comparative Study of Foraging Behavior and Reproductive Strategies in Female and Male Populations of Gynostemmma pentaphyllum Study on reproductive ecology of Kobresia pygmaea population in alpine meadow Pollen and resource limitations to lifetime seed production in a wild population of Ceratoides arborescens Comparation of Pollen Viability and Stigmatic Surface Morphology and Receptivity in Three Reproductive Strategies of Taraxacum