If an acrostic is made by the first letters of each, what's the first word of each line?

Question

Like:

It is planting something in my mind.

Looks like leaves, maybe vines.

As it grows, it leaves behind,

Though still a seedling, something mine.

I’ve heard its whisper, taken my time,

Included my knowledge and maybe a rhyme,

A splash of words (just to refine),

Secret meanings are intertwined.

The word of each line forms a sentence. What is this called?

Answer 1

The first word of each line makes this sentence:  

It looks as though I've included a secret.  

I'm not sure what that's called.