Phyllanthus emblica / Indian Gooseberry.
http://en.wikipedia.org/wiki/Phyllanthus_emblica
the main proprietary ingredient in Strivectin.
http://www.epinions.com/content_4185038980
Essentially StriVectin-SD is based on Klein Becker's proprietary Striadril Complex consisting of Phyllanthus Emblica Fruit Extract. Striadril, an active ingredient containing patented pentapeptides that significantly improve the appearance of facial wrinkles, stretch marks, and minor skin imperfections by aiding the build-up of collagen. Unlike many other anti-aging treatments, Striadril is more stable, causes less irritation, safer, and more effective.
http://www.cosmeticsurgery-news.com/strivectin_sd.html
notice the very high vitamin c content of the fruit.. but evidently, there is something in the complex of the fruit that enhances its effect on the skin.