I got a few of these as seedlings years ago, and based of rate of growth alone they appear to be the real things... but leaves don't look like adult plant and these are now 6 years old. But what else could they be?

Below is adult (20 year old plant, already flowered multiple times) in southern California (not my plant).

Here is my six year old seedling... only about 8" tall, but leaflets seem too wide.. but perhaps I am must impatient and it will look more like the above plant in another 6 years?