Virtual Nature Trail

Scientific Name
: Trillium erectum
Common Name: Red Trillium

(Information for this species page was gathered in part by John Florida for the Spring 2006 section of Biology 220W at Penn State New Kensington)

A red trillium flowerThe red trillium (Trillium erectum) has a number of common names which are reflective of many of its distinctive ecological, anatomical, and chemical properties. The trillium flowers have a faint, but pungently foul odor which has variously been described as resembling the scent of a wet dog or of rotting meat. This stench has led to names such as “stinking Willie” and “stinking Benjamin.” Extracts of the roots and poultices of the entire plant have astringent and antiseptic properties and were used by Native Americans in a variety of medicinal applications including the control of uterine bleeding during parturition. So, names such as “birthroot” (which was mispronounced as “Beth root” and “bath root”) have been applied. It is sometimes also referred to as “nosebleed trillium” because of these astringent applications. It is also called “snakebite plant,” “rattlesnake root,” “cough root,” “milk ipecac,” and “Indian balm.” Its distinctive, three-leaf structure has generated names such as “three-leaf nightshade,” and “Indian shamrock,” and the tendency of the red, flower head to droop downward is described in the names “nodding trillium” and “nodding wake-robin.”

Habitat and Growth Pattern
Trillium erectum
is a monocot plant of the lily family. It is a perennial wildflower that grows sometimes in great, colonial masses in cool, moist, but well drained soils of woodland ecosystems throughout the eastern half of the United States. In Pennsylvania, T. erectum are especially abundant in hardwood forests (especially those that contain maple and beech trees). These plants are most abundant on our Nature Trail in the mixed beech forest just down slope from the “Wildflower” section of the trail.

Trillium erectum blooms in the early to mid spring depending on weather and local conditions. On our Nature Trail, the red trillium is most commonly in flower from mid April to mid May. Flowers are typically deep red in color (but may vary from pink to a lavender red) and sit atop a 2 to 8 cm tall stalk. Color change in the petals is an indication that pollination has occurred. The three, lancelet-shaped flower petals are 3 to 7 cm long and up to 3 cm wide. Blooms on an individual plant may, under ideal conditions, persist for a month. Plants need to reach an age of 15 years before they bloom. Plants can live for up to 30 years.


Flower removal is a very serious stress on a T. erectum individual. Picking flowers may result in the death of the plant or, if the plant survives, render the plant unable to flower for, possibly, the next seven years.

The leaves of T. erectum contain calcium oxalate crystals which make them unpalatable or even toxic to many herbivores (including humans). White tailed deer and woodchucks, however, do graze on T. erectum. Deer browsing, in particular, may result in local extirpation of the plant. Competition by fast growing, exotic, invasive species such as garlic mustard has also reduced the densities and distribution of T. erectum.

Pollination and Fruiting
The T. erectum flowers are pollinated by flies that are attracted to their previously mentioned foul odor. The flowers form dark maroon, fleshy, berry-like, seed capsules. The seeds have oily appendages called “elaiosomes” which attract a wide variety of insects (especially ants). These elaiosomes (also called “ant snacks”) stimulate the insects to gather and disperse the T. erectum seeds. Other hymenopterans (like yellow jackets) and small mammals (like chipmunks) also actively gather, feed on, and inadvertently disperse the T. erectum seeds. Distribution of red trillium, then, is dependent upon the abundance and movements of these animals. Dispersal distances and rates for T. erectum, again because of the ecology and behaviors of its dispersing symbionts, are quite low. Seasonal limitations in the northern edges of T. erectum’s distribution (i.e. the early onset of cold winter temperatures) may prevent seeds from fully maturing and may be the functional ecological barrier to the northward distribution of this species.

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