"Especially not" is a fragment.
Answer:
Explanation:
Now that our speaker has told us that nature is gold before it's green, he goes on to say that gold is the hardest hue, or color, for nature to hold, or keep. So the first color we see in spring doesn't stick around very long. Hold rhymes with gold, which means we've got a rhymed couplet here.
Um I think personification? if there was a little more context i'd be more sure but i'm pretty sure it's personification