Forest tree with scarlet seed, I hear, a first rate Toona ciliata (3,5)

'rate toona ciliata' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.

'forest tree with scarlet seed i hear a first' is the wordplay.
I cannot quite understand how this works, but
'tree' could be 'cedar' (cedar is a kind of tree) and 'cedar' is found in the answer.
'scarlet' could be 'red' (synonyms) and 'red' is located in the answer.
No letters remain.
This explanation may well be incorrect...

Can you help me to learn more?