Source sanction to a little bit of a plant (7)
I believe the answer is:
rootlet
'bit of a plant' is the definition.
The definition and answer can be both plants as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'source sanction to a little' is the wordplay.
'source' becomes 'root' (both can mean the origin of something).
'sanction to' becomes 'let' (I've seen this in another clue).
'little' means to remove the last letter (the word is not quite complete).
'root'+'let'+'a'='rootleta'
'rootleta' with its final letter removed is 'ROOTLET'.
Can you help me to learn more?
(Other definitions for rootlet that I've seen before include "underground development" , "Small radical" , "Little plant part" , "Small branch of a plant's "anchor"" , "Natural lateral support for a climbing plant" .)