Feathery layer: new article in plant (5)
I believe the answer is:
henna
'plant' is the definition.
(plant which henna dye is made from)
'feathery layer new article' is the wordplay.
'feathery layer' becomes 'hen' (feathered bird which lays eggs).
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'article' becomes 'a' (the indefinite article in English).
'hen'+'n'+'a'='HENNA'
'in' acts as a link.
(Other definitions for henna that I've seen before include "hair colouring" , "Vegetable dye" , "Reddish cosmetic dye" , "Pigment used on skin" , "Shrub used for cosmetic colouring" .)