Black-eyed Susan,
Rudbeckia hirta, is a common plant that is recognized by many. It grows in a wide variety of disturbed habitats and can produce blooms on the poorest of sites. So, if I’m working to increase populations of rare plants, why would I be so interested in this common flower.
Black-eyed Susan grows as either an annual or a biennial. Early season seeds usually produce clusters of basal leaves that survive the winter and grow to produce the earliest blooms. Late season seeds wait and germinate in early spring and normally produce late season flowers. The challenge facing plants that must annually produce new populations from seed is having suitable unoccupied ground in which to grow. Clumps of Black-eyed Susan show up in different areas each year. Learning the dispersal mechanisms employed by common plants will help me to understand the possible ways that rare plants move through the landscape.
The plant dies after producing seed, so it’s important for that seed to be spread out into suitable growing sites. The long flower stalk is quite strong and limber and can stand erect long after death. The stalk sways in the wind or is bounced back and forth by birds and allows the seeds to fall or be thrown several feet from the plant. Why then do these populations die out so quickly and how do new populations develop far from other plants?
In order for the plant to successfully develop, the seed must fall in a place that is not already full of other plants. Bare ground is typically a temporary situation. Plants soon fill any void and make it more difficult for new plants to develop from seed. So the populations of these short lived plants are constantly jumping around the landscape. Strangely, many people won’t understand what these plants are doing, because they are used to seeing extravagant populations of Black-eyed Susans growing in areas of mass disturbance and don’t notice when the flowers are no longer there.
Of course, there are insects benefiting from this plant. That little katydid looks much like the one I saw yesterday on the New Jersey Tea. Possibly it’s just a younger version.
The June prairie has a very distinctive look. The tall grasses are putting on a lot of leafy growth and have a bright blue-green blush. Hidden among the grasses are a multitude of plants just on the verge of blooming. The anticipation of the soon to arrive blooms is similar to the feeling I used to get as a child during the last days before Christmas.
Thanks to the abundant rainfall, there is an early show this year. Black-eyed Susans have bloomed in numbers far greater than normal. These plants normally behave as annuals or short-lived perennials. The right combination of weather conditions will stimulate germination of the seeds and create an uncommon abundance of plants.
This is our source of early color. Black-eyed Susans are quite common across their range and in some places are thought of as a slightly weedy plant. It’s odd that so many people equate abundance with weediness. Its numbers vary greatly from year-to-year at Blue Jay Barrens and I see it as another native species maintaining its presence in the community mix.
Besides color, it’s a major food producer on the prairie right now. This bee has picked up a nice load of pollen. Butterflies occasionally visit these flowers, but it’s mainly bees, flies and beetles that I find here. It makes me wonder if Black-eyed Susans are poor nectar producers.
Of course, the mark of a true native plant is its ability to sustain an abundance of animals with its various vegetative parts and still produce seed for future generations. Various herbivorous life forms will feast upon the flowers, petals, leaves, stems and roots of this plant. It may end the season as a pretty raggedy looking specimen, but it will still achieve its primary reproductive objective.
