A small flower with a stem twisted round the rooftop (6)
I believe the answer is:
stream
'a small flower' is the definition.
'stream' can be an answer for 'flower' (I've seen this in another clue). I am not sure about the 'a small' bit.
'a stem twisted round the rooftop' is the wordplay.
'twisted' indicates anagramming the letters.
'round' means one lot of letters goes inside another.
'the rooftop' becomes 'r' (top of the word 'roof').
'a'+'stem'='astem'
'astem' anagrammed gives 'steam'.
'steam' placed around 'r' is 'STREAM'.
'with' acts as a link.
Can you help me to learn more?
(Other definitions for stream that I've seen before include "schoolchildren grouped together" , "flower" , "comprising a load of drips?" , "Brook or rivulet" , "not taken in mixed-ability group" .)