You will be extremely hard pressed to get this tree seed. As a native seed collector - they are almost impossible to collect. 1st. Rare here in southern ontario only found on the sandy shores inland to about 5kms and locally in some locales on sandy spots inland. 2nd. The fruit is extremely high up in the canopy and when they mature they are quickly gobbled up by the birdies. However there are seed houses that carry this seed in the US - There is schumachers seeds in mass. This seed will not grow in the north in latitude beyond Toronto and strictly requires sand loam

Try this link, a Canadian source for seed

http://www.plantexplorers.com/twiningvine/product_info.php/cPath/25/products_id/634