The answer is that once you’re able to definitively recognize it in at least one form, you’ll start to recognize similar, not quite identical forms.
The sapling form is not quite the same as the vine form, which is not quite the same as the very thick hairy vine that it eventually transforms into. But once you know one, you can start to recognize the others due to at least some parts of the plant matching what you already know. And then the other parts of the plant, which you hadn’t previously recognized as being how poison ivy can look, are added to your personal visual memory, too.
I don’t know, it’s hard to explain. It’s like if you saw a chihuahua and a Great Dane, you might not recognize them as being the same species. But if you see enough dogs in between, eventually you’ll see that they have something in common.
The sapling form is not quite the same as the vine form, which is not quite the same as the very thick hairy vine that it eventually transforms into. But once you know one, you can start to recognize the others due to at least some parts of the plant matching what you already know. And then the other parts of the plant, which you hadn’t previously recognized as being how poison ivy can look, are added to your personal visual memory, too.
I don’t know, it’s hard to explain. It’s like if you saw a chihuahua and a Great Dane, you might not recognize them as being the same species. But if you see enough dogs in between, eventually you’ll see that they have something in common.