Perplex foremost of gardeners with passion flower (8)
'flower' is the definition.
(thesaurus)
'perplex foremost of gardeners with passion' is the wordplay.
'perplex' becomes 'fox' ('fox' can be a synonym of 'perplex').
'foremost of' says to take the initial letters.
'with' says to put letters next to each other.
'passion' becomes 'love' ('love' can be a synonym of 'passion'**).
The first letter of 'gardeners' is 'g'.
'fox'+'g'+'love'='FOXGLOVE'
(Other definitions for foxglove that I've seen before include "Animal and hand-covering for a plant" , "Plants of the genus Digitalis" , "Tall plant with purple or white flowers - vulpine?" , "that grows wild" , "Plant (of the genus 10 down) with bell-shaped flowers" .)
But I've got no explanation for this one! Could you help me understand?