Most gardeners have their favorite sources for plants.
Some like to shop from home using catalogs. Others prefer to shop on-line. Many want to see what they are buying and frequent local nurseries and garden centers to find the plants they want. Your favorite sources might serve you well for most plants, but if you want to buy something unusual, a bit of detective work might be necessary. Start by knowing, with as much certainty as possible, the correct name for the plant you are looking for.