Oh, on one of my prize Iris, I sometimes must cut the outer sepal, or the flower bud will entirely die. (nakedpastor.com)
The buds are harvested before their hour, Then must be steamed or boiled before they yield The tongue - like sepals with their toothsome bracts Attached to the receptacle, or heart, That stores the petals of the future flower. (firstthings.com)
At Key Stage 2 (Age 7 + to 11, Years 4 to 6) schools have to teach the following: Growth and reproduction; the main stages of the human life cycle; reproduction; the parts of the flower [for example, stigma, stamen, petal, sepal] and their role in the life cycle of flowering plants, including pollination, seed formation, seed dispersal and germination.» (faith.org.uk)