Influence of Seed Source Upon Phenology of Flowering of Spartina Alterniflora Loisel. And the Likelihood of Cross Pollination

Seedlings of Spartina alterniflora Loisel., from seed harvested from nine marshes ranging from Maine to Virginia, were grown for three seasons in plots established on two different soils in Delaware and were flooded regularly with water from two estuarine sources. Substantial differences in the time of flowering were observed. Each year plants from Maine seed flowered first and were followed by those from Connecticut and New York. Last to flower were plants from Virginia seed. The latter initiated flowering after flowering of the Maine source had been completed. These two would not cross‐pollinate under this circumstance. The phenology of anthesis and number of seeds set on inflorescences enclosed in bags indicate that this species is largely open pollinated.