We were hiking in Sequoia National Park recently and came across a young black bear eating wildflowers in a marshy area where 2500-year-old Sequoia trees cast their shadows on a rich array of wildflowers. The bear ambled through the greenery, grabbing flowers along his route with his paw and nibbling the flowers off the stems. Here is a big animal that inspires fear in people was eating wildflowers with drunken ambition.
A few years earlier, in central British Columbia, we found a grizzly bear eating clover flowers beside a logging road. She was grazing the flowers and rolling in the fragrant bed of clover. We were glad to be in a vehicle as this bear, unlike the black bear, has a reputation as a serious predator.
Who knew that wildflowers are an important part of bear’s diets. Elk, deer and wild sheep eat flowers which are full of nutrition because of their complicated anatomy. Rabbits, mice, rats, pika also eat flowers, though they live on the other parts of plants when flowering season is over. And cattle eat a disproportionate share of wild plants, often destroying local populations of plants.
Many people who go outside in the spring or summer marvels at the diversity and beauty of wildflowers. And while some people may ignore wildflowers, flowers can pull us into the deep richness of the natural world, the basic source of our own existence. Wildflowers are one of the most important things we will ever see in our lives. They are a window into a hidden world.
Wildflowers thrust their beauty up into the summer world, and each plant species has evolved that flower shape to successfully create seeds in that environment. Not only are flowers beautiful to us, but they are profoundly functional, and they are a survival strategy for the plant in its effort to pass its genes down to future generations.
Lots of plants don’t have flowers, such as mosses and lichen, and algae. These plants reproduce with spores, not seeds. Spores don’t come from flowers, but from almost microscopic structures hidden on these strange plants. Grasses have flowers but they are difficult to recognize as flowers without close observation.
What is a flower? Why are they here? Why are some flowers big and “showy” while others are tiny? Why do some smell good while others have no scent at all?
Sex
Flowers are the plant’s sex organs. And just like birds or humans, they put on a show to get fertilized. They have a “stigma” which collects the male sex cells, called pollen, and that pollen is delivered to the ovary via the “style”. The ovary has “gametophytes” which are like the eggs in a female mammal. The gametophyte has only half the needed genes to make a viable seed. The pollen provides the other half of the needed genetics to make the fully viable seed.
In mammals the male sperm serves the same function as the plant’s pollen and sperm provides the needed compliment of genes to the egg create an embryo. Plants also have embryos that grow inside their ovaries.
When you look at a wildflower, some of what you see are male sex organs. The anthers are often fuzzy yellow features that release pollen into the environment. Sometime anthers are little banana shaped units held on the end of a long fiber, called a filament. The anthers put the male sex cells out into the world to be stuck to a visiting insect or blown in the wind.
But the real show that a plant puts on are the flower’s petals. The colorful leafy stuff around the above-described sex organs exist to attract insects who dive into the sex organs of the flower and bring pollen from other flowers and take the pollen from this flower to other flowers elsewhere. The insects are going after a little bit of nectar that the flower creates as an award for their services. The petals are made of the most sublime cells, that include pigments to appeal to insects or hummingbirds. But at the same time, some of what we think of petals are often just specialized leaves (called bracts) that hang around the petals. Bracts can be colorful too.
The shape and color of the “petals” are made by evolution to work with a type of insect to achieve fertilization. Here we get into the real wonders of nature. Insects change over time to be compatible with various flowers. The flowers change over time (evolve) to be compatible with the insects. This is co-evolution, a truly mind-bending process if you really consider how it can possibly happen. These plants and animals are “communicating” over tens of thousands of years.
The big showy datura, or jimsonweed is a perfect example of this co evolution. The big white flowers open at night and a hawk moth visits the plant to drink the nectar found deep in the flower. In the process the moth rubs pollen from other datura flowers on the female receptor of that flower and absorbs the pollen from the anthers. The flower is “designed” for the hawkmoth. The hawkmoth is perhaps “designed” for the datura.
Yet other flowers don’t wait for insects like bees, of which there are hundreds of native species. Many flowers release their pollen into the wind in the “hope” that it will fall onto the female parts of a flower of the same species and fertilize that flower. Others are pollinated by bats or hummingbirds or other birds.
Pollen from completely unrelated flowers will not fertilize a species’ flower. If the pollen comes from a close relative, a different subspecies for example, the fertilization may happen to create a hybrid. This can happen with mammals too in some cases. Scientists think that Neanderthals in Europe 40,000 years ago were breeding with our ancestral humans. As a result we all have some neaderthal genes.
Art
Aside from all this sexual biology, flowers are the ultimate artists. They are like the dancer on the stage, twisting and folding to be beautiful in form. Imagine the blue delphinium in the wetland, its dark blue keel advertised by flat petals. Or the sunflower and its thousands of relatives that is not one flower, but hundreds of flowers mounted on a flat plain with a rim of “ray flowers” that show off to attract the bees that will trek across the tops of the inner flowers and satisfy their sexual needs.
Why do we perceive flowers as beautiful. We marvel at wildflowers and take their pictures. We buy domesticated flowers in bunches and give them to people to mean love or sympathy or happy birthday. Flowers are embedded in our spirits and our psyches.
But wildflowers are not showing off for us. We are chance observers of their sex play that has been going on for about 140 million years. When you look at the wood lily with its orange or red flowers, you are looking at the product of untold generations of previous plants that experimented with flower “design” over millions of summers.
How humbling to see this reality and to lie down in a flower filled mountain meadow and do a little dreaming.
Tom Ribe
