If you can't find a plant in the database just use the "contact us" link on the search page to send us the plant name, and we'll add it. The reason we decided to do it this way (instead of letting people add plants to the database) is to keep the data as accurate as possible. We realized that if a plant is added incorrectly, it would create all sorts of ploblems, including making it difficult to connect gardeners by the plants they own, and getting the proper photos.
So if you have a plant which isn't in our plant encyclopedia, please take a minute and send us the name(s). We have 2 people working almost exclusively on adding and researching plants, so in time (with your help) we should be able to get ahead of the curve!