Water color's primary characteristic is its transparency
Answer: outlandish
Could be unusual as well, but outlandish is better.
Hines was the piano player that played in the style of phrases
My interpretation of this is that the author was hoping for something futile - they 'grew a flower' (put effort or hopes toward) that can't be bloomed (is pointless or futile, will not produce anything) that can't come true (their effort/hope is just a hopeful dream). Basically, the author hoped for something that was not possible.
