Plants with fronds (5)
I believe the answer is:
ferns
'plants with fronds' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ferns that I've seen before include "Flowerless plants with feathery green leaves" , "Ancient plants" , "Frondy plants" , "Flowerless plants with feathery or leafy fronds" , "Plant, maidenhair or tree say" .)