'the rose tree is not to bear, the violet blue, nor lily fair'.- other beautiful, sweet smelling flowers, it is not made to have the other flowers.
'and if this tree were discontent, or wished to change its natural bent'.- 'bent'- natural talent, rhyme scheme 'discontent' and 'bent'.
'it all in vain would fret.'- the rose tree can only have flowers of its own.
'and should it fret you would suppose'- 'you' direct address, draws the reader into the poem, conversational tone.
'had ever smelled it's rose's scent, or it could ne'er be discontent.'- 'discontent' is repeated twice- emphasises how unhappy we are if we waste our energy on ENVY. (the tree wants to change because it has not appreciated its own good qualities.
'like such a blind and senseless tree'- simile compares the tree to envious people.
'with care and culture all may find.'- alliteration, emphasises positive qualities.
'some prettyflower in their own mind , some talent that is rare.'- 'pretty flower' metaphor for the positive qualities each person has, 'talent' takes time to bloom.