Look into the top of the flower; what figure do the tips of the six flower leaves form?
Using the names calyx and corolla, describe the circle of flower leaves as to number, colour, and relative position.
Find the stamens and describe as to number and position; find out how the stamens are fitted to ensure that the pollen will get upon the visiting insects.
Find the pistil and describe its shape. How is the stigma fitted for receiving the pollen that is carried by the insect visitors.
To the teacher.—The trilliums attract insects by their large white and purple flowers, which are held up by their long stalks high above the three broad leaves. The strong carrion-like odour of the purple trillium is attractive to flies and beetles, while bees and butterflies find the fragrance of the white trillium more to their liking.
The root-stock serves as a buried store of food to tide the plant over the drought of late summer and the severe cold of winter. The well-stocked cellar also explains the flourishing condition of the plant in early spring. The six stamens stand on close guard around the pistil, and insects forcing their way to the nectaries are well peppered with pollen.
Continue the observation work by means of field exercises such as the following:
What change takes place in the colour of the white trillium as it grows old?
Find the ripened seed pods of the trillium, open them, count the number of chambers, and examine the seeds.
Do trilliums grow from the same root-stock year after year?