Abstract After 0 to 32 days of stratification, sweetgum (Liquidambar styraciflua L.) seeds from 3 stands near the mouth of the Mississippi River germinated faster than seeds from 15 stands farther north in Mississippi, Alabama, and Louisiana. There was evidence of a clinal response in rate of germination, in which an increase of 10 days with winter temperatures ≤ 0° C at the seed source was associated with an additional 1 1/2 days to attain 90 percent of total germination.