Feathered layer initially needed with a plant (5)
I believe the answer is:
henna
'plant' is the definition.
(plant which henna dye is made from)
'feathered layer initially needed with a' is the wordplay.
'feathered layer' becomes 'hen' (hens lay eggs).
'initially' suggests taking the first letters.
'with' means one lot of letters go next to another.
The initial letter of 'needed' is 'n'.
'hen'+'n'+'a'='HENNA'
(Other definitions for henna that I've seen before include "Cosmetic plant dye" , "Reddish dye for hair etc" , "Natural hair dye" , "Beauty aid" , "Reddish-brown hair-dye" .)