Old World Diamond Flower (Oldenlandia corymbosa) Rubiaceae (Coffee Family)
Rustweed (Polypremum procumbens) Tetrachondraceae
John and trekked out to where the wild things grow today, only to retreat beat by the heat. (Not John, I was the wimp.) But not before a familiar observation: clustering of similar yet unrelated flowers in a specific habitat. A hunch rooted only shallowly in the botanical literature, so we’re in the realm of suspicion, not fact. Maybe that heat got to my head.
Ever visit a natural place and perceive many unrelated flowers to look alike, especially in coloration? A wet meadow may feature bright yellow xyris, bright yellow St. Johnsworts, bright yellow coreopsis, bright yellow heleniums, bright yellow smallfruit beggarsticks, bright yellow ludwigias, and more, although not to the exclusion of other colors. Large white giant whitetops and large white alligator-lily grow together. Where does imagination end and correlation begin?
Color clustering might be conceivable if you look at it this way: pollination is essential for existence, so a plant is going to exist only where its proper pollinators are. Different types of pollinators have different frequencies in different habitats, influencing the plant species composition, and thus perhaps trends in flower color and size.
Furthermore, and only a notion, maybe there is positive feedback, say, for example, a happy place for bumblebees brings bumble-visited flowers, which then draw more bumblebees, and these in turn support more bumblebee-o-centric flowers. Bees like yellow.
This morning’s site, Haney Creek Natural Area in Jensen Beach, Florida, has a dry, sun-cooked, sterile, disturbed gravel road with a preponderance of very small white flowers. “The same” road with essentially the same species runs behind my home, where almost all the flowers were about ¼ inch or less in diameter and white. All of the photos today are taken in one small flower patch at the same magnification except for the over-magnified Buttonweed whose flowers are essentially the same size as the others. Maybe that harsh habitat fosters tough little bees or mini-flies adapted to tiny white blossoms.
That harsh environment is probably not a place for plant species with big, showy, “expensive” flowers to support large insects demanding abundant rewards in nectar or pollen. Skimpy man habitat, skimpy flowers, skimpy pollinators, perhaps.
Floral resemblance among the species growing intermixed there can be striking. Below are photos of two unrelated plants: native Rustweed (Polypremum procumbens) and non-native Old World Diamond Flower (Oldenlandia corymbosa). Their flowers are “stamped from the same mold.”
As an aside, Rustweed goes through a remarkable seasonal color change. It starts out green and as the summer progresses switches to a coppery rusty color.
The other species consorting with the Rustweed and Diamondflower looked much the same too. What makes the similarities even weirder is that the “flowers” are not all true flowers. In the Canadian Horseweed they are a collection of smaller flowers collected into a white flower-head. In the Sandmat and in the Euphorbia, the “petals” are itsy white leaves surrounding smaller flowers. Yet they all have converged on the same general appearance, perhaps to accommodate the same floral visitors.
There must be something good about that “little white flower” look, because everyone on the berm is doing it. And that good thing is probably shared pollinators. Just a hunch.