Purple Trillium, Large-flowered Trillium and Painted Trillium all flower in the month of May. Another name for trilliums is Trinity Flower, referring to the plant’s parts which are arranged in three’s or in multiple of threes. Three leaves, three sepals, three petals, six stamens, three stigmas and an ovary that has three compartments. (Photo: Purple Trillium, Trillium erectum)
Large-flowered Trillium (Trillium grandiflorum), also known as White Wake-Robin, is our largest and showiest species of trillium. It can be found throughout New England’s rich woods, sometimes carpeting large expanses of the forest floor in May and June. All species of trillium, as their name implies, have parts arranged in threes, or in multiples of three (petals, bracts, leaves, stamens, carpels).
Nectar, not fragrance, attracts long-tongued bumblebees to Large-flowered Trillium’s funnel-shaped blossoms. Self-pollination occasionally occurs, aided by the fact that as the flowers age, their stigmas reflex downward and come in contact with the anthers. The flowers are exceptionally long-lived, remaining open and fertile for two to three weeks.
When they first open, Large-flowered Trillium’s petals are white. As the flowers age, they become pale to deep pink (see insert). (There is also a pink form of Large-flowered Trillium which is pink from the time of opening.) The seeds that form are dispersed primarily by ants, but yellow jackets, harvestmen and white-tailed deer also contribute to their dispersal. It takes two years for the seeds to germinate and once established, Large-flowered Trillium plants typically require seven to ten years in optimal conditions to reach flowering size.
As a dispersal mechanism, some plants have fatty structures called elaiosomes attached to their seeds’ coats which are very appealing to ants. After collecting a seed and carrying it back to its underground nest, the ant eats the elaiosome (or feeds it to ant larvae) and discards the intact seed in an area where waste and dead ant bodies are stored. Germination is highly likely in such an ideal environment, making myrmecochory a win-win situation. Trillium, bloodroot and violets are some of the thousands of plants that have elaiosomes attached to their seeds.