I wonder if anyone has successfully crossed the Rubus Spectabilis, 'Salmonberry', with a Domestic Raspberry. Would sure expand the potential acreage for berry growers. You could grow your berries on poorly drained marshland and harvest from a perennial berry bush. I think the Salmon berry plant lives for more than two years. I do have some superior selections of Salmonberry , but have not seen any hybrids with other Rubus Species so far.
You could grow raspberries on damp ground if such hybrids turned out to have that ability. It depends on what combination of characters it is possible to obtain, when any plants are crossed there are existing limitations on what results are possible. The raspberry plant is a perennial shrub. Only the individual canes are biennial, not the entire plant.
According to Wickipedia, the Samonberry has perennial fruiting wood. Raspberries are Biennial and after the second year, the fruiting canes die. http://en.wikipedia.org/wiki/Salmonberry
Your previous statement was >You could grow your berries on poorly drained marshland and harvest from a perennial berry bush. I think the Salmon berry plant lives for more than two years<