Sentence:  My great grandmother , I have been told , made her garden her great pride ; she cherished rare and delicate plants like oleanders in tubs and wall-flowers and lemon verbenas in pots that had to be wintered in the cellar ; she filled the waste spots of the yard with common things like the garden heliotrope in a corner by the woodshed , and the <WSD>plantain</WSD> lilies along the west side of the house . 
Meaning of the word marked with <WSD> tags:  any of numerous perennials having mounds of sumptuous broad ribbed leaves and clusters of white, blue, or lilac flowers; used as ground cover