Sentence:  Dahlias are one of my favourite summer flowers. These magnificent plants come in a wide variety of flower forms, sizes and colours... The <WSD>pompon flower</WSD> is two inches in diameter and is produced on plants three to four feet in height. 
Meaning of the word marked with <WSD> tags:  Any of various flowering plants in the genus "Dahlia", family Asteraceae; dahlias.