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