There was a thread awhile back that I cannot find asking about vegtable source TriFlex. I guess most were made out of cartiledge of one form or another. I found out recently that I have osteoarthritis and I was searching for something similar because even though I'm not a vegaterian, swallowing shark cartiledge grosses me out. Anyway, I found Liquid Flex at GNC that comes from non-shelfish, vegetable source. It was $14.00 on sale for a 1 month supply.
If the person is on the board still somewhere, I hope this helps.