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.
Flowers that have limited opportunity to attract pollinating insects, such as those that mature very early in the spring, often are self-fertile – they can produce seeds without the benefit of pollinators. Wild Ginger (Asarum canadense) is a perfect example of this.
Wild Ginger has six inner stamens and six outer stamens, all of which produce pollen. In a newly-opened flower, all of these stamens lie flat against the “floor” of the flower. When the stamens are in this position, pollination is achieved by insects (often flies or beetles attracted to its rotten meat coloring and scent) as the pollen cannot reach the receptive stigma on its own. Wild Ginger hedges its bets, however. Whether or not pollination occurs early in its development, later in the life of the flower both inner and outer stamens move into an upright position, thereby moving closer to the stigma. Because the flower is oriented downward, this change in the position of the stamens allows for the pollen to fall onto the stigma, thereby accomplishing self-pollination. With or without pollinators, Wild Ginger succeeds in producing seeds.
How incongruous that a spring ephemeral as beautiful as Dutchman’s Breeches (Dicentra cucullaria) is extremely debilitating to any cow that eats it. The most common bovine symptom of poisoning by Dutchman’s Breeches is a staggering gait (it’s referred to as “staggerweed” by some farmers) and a decrease in milk production. However, according to the Veterinary Medicine Library at the University of Illinois, there are far more severe symptoms. “Experimental feeding of these plants to steers caused sudden trembling which increased in severity, frothing of the mouth, ejection of partially digested stomach contents, and convulsions. The eyes became glassy, and the animals went down and moaned as if in pain.” Certainly this is a plant one should admire and experience visually, not gastronomically.
Spring Beauty, Claytonia virginica, is a familiar and welcome spring ephemeral that carpets the forest floor at this time of year. Within a population, its blossoms range in color from white to a deep pink. You don’t usually find a range of colors within a given population, as one color is often more successful at reproducing and it eventually becomes dominant, while the other colors are eliminated.
There is a reason why both colors of Spring Beauty continue to flourish within a given population. A red pigment interacts with two chemicals (flavenols) to produce the range of color. Plants with a high percentage of flavenols produce white flowers. These flavenols are a deterrent to herbivores, so in years when there are lots of slugs, white-flowered plants are more successful in producing seeds. This would lead one to conclude that eventually pink-flowered plants would diminish in number. However, white-flowered Spring Beauty is also parasitized by a type of fungus called a rust, Puccinia mariae-wilsoniae, which causes orange spotting and often serious deformation of the plant (see photo).
Thus, in years when slugs are numerous, white-flowered Spring Beauty flourishes and produces seeds. In years when slugs are not numerous but fungal infection is high, pink- flowered plants reproduce more successfully. This sporadic success of both white and pink Spring Beauty is why we continue to find them both in the same population.
The flower of Red Trillium (Trillium erectum), also known as Stinking Benjamin and Wake Robin, is familiar to many, as it is one of our more common spring ephemerals. The three reddish-maroon (some populations have white, yellow-green, or paler red) petals of its flower are colored and smell faintly like rotten meat. Lacking nectar, these flowers rely on deception to bring in pollinators which are primarily flies and beetles that are typically attracted to dead animals.
Once a Red Trillium flower is pollinated, the Hershey Kiss-shaped red fruit begins to develop. The seeds of Red Trillium have oily appendages called “elaiosomes” which attract a number of insects, particularly ants. These elaiosomes (also called “ant snacks”) contain lipids and protein highly sought after by ants. The ants carry the seeds down into their underground tunnels where they feed the elaiosomes to their larvae and dispose of the seeds in their compost pile. Here they they put their droppings, or frass, as well as dead ants. Conditions for germination are ideal in such a spot, and, in fact, research shows a greater germination rate for seeds with elaiosomes than those without them.
Miterwort, also known as Bishop’s–cap, is named for the resemblance of its fruits to the hats (known as miters) worn by bishops of the Roman Catholic Church. If you examine a flower closely, you will see its delicate, 5-pointed, snowflake-like beauty. Each flower is in the shape of a tiny cup, with dissected petals arising from the rim of the cup, resembling fine lacework. There is a glandular ring of nectar-producing tissue inside the cup which attracts small bees, flies and ants. Once pollinated, the flowers produce open seed-containing capsules. Water, not animals, is the dispersal agent for Miterwort’s seeds. The capsules orient themselves so that their opening faces upward. When it rains, the falling rain drops splash the seeds out of the capsules, dispersing them up to three feet away from the parent plant. The distance traveled by the seeds is dependent upon both the size of the raindrop and the distance that it has fallen before landing in a capsule.