Bed with a single flower showing shrub of the hawthorn family (11)
I believe the answer is:
cotoneaster
'shrub of the hawthorn family' is the definition.
'cotoneaster' can be an answer for 'shrub' (cotoneaster is a kind of shrub). I'm not certain of the 'of the hawthorn family' bit.
'bed with a single flower' is the wordplay.
'bed' becomes 'cot' (cot is a type of bed).
'with' is a charade indicator (letters next to each other).
'a single' becomes 'one' (a single thing - only one).
'flower' becomes 'aster' (type of flower).
'cot'+'one'+'aster'='COTONEASTER'
'showing' acts as a link.
Can you help me to learn more?
(Other definitions for cotoneaster that I've seen before include "Plant" , "Shrub with red berries" , "Red-berried garden shrub" .)