Although it is rooted to a southern Idaho mountaintop, Christ’s paintbrush (rhymes with “mists”) has gone national. The U.S. Forest Service has highlighted the plant on its Celebrating Wildflowers webpage for the Intermountain West.
Christ’s paintbrush, which only grows in one small area, is an unusual kind of hybrid plant. In her Master’s degree research at Boise State University, Danielle Clay found that it is a homoploid hybrid. Although closely related plant species often cross breed, they rarely produce new homoploid hybrid species.
Many hybrid offspring have two sets of chromosomes, one from each parent. But homoploid hybrid offspring end up with just one set and so have the same number of chromosomes as both of their parents. This usually results in homoploid hybrid offspring crossing back with one or both of their parental species until their unique genome disappears. But occasionally, as with Christ's paintbrush, homoploid hybrid offspring are so different from both of their parental species that they cannot cross breed and a new homoploid hybrid species can develop.
After I wrote about Danielle’s work for BSU’s Division of Research and Economic Development, the university allowed us to reprint the piece, with Danielle’s photos, in the Idaho Native Plant Society's newsletter, Sage Notes. The Forest Service saw the article and BSU gave the agency permission to use the story and photos from the INPS newsletter on their website.
Celebrating and Learning about Wildflowers
While Christ’s paintbrush boasts a unique origin, all paintbrushes are unusual plants. We talk about their red, yellow, pink, or purple flowers, but what we really see are the colorful flower bracts that nearly hide the tiny, green flowers. If we looked at the roots of one of these plant under a microscope, we would see finger-like structures called haustoria. Paintbrushes use these to tap into the roots of other plants to obtain water and minerals. These colorful wildflowers are not true parasites because they have green leaves that produce food through photosynthesis; paintbrushes are called hemiparasites, or partial parasites. This is why we find them sprinkled across landscapes like paprika and growing next to other plants, such as the sagebrush in the photograph.
The Interesting Plants page of the Celebrating Wildflowers website introduces Thieves from the Heath - Mycotrophic Wildflowers. These are true parasites, as they have no chlorophyll. This frees them from the green color scheme of most other plants and lets them explore other options. For instance, Indian pipe, or ghost plant, is a translucent, ghostly white. This unusual plant was Emily Dickinson's favorite flower.
Unlike most true parasites, mycotrophic plants do not get food and water directly from other plants. Instead, they tap into the mycorrhizal fungi that coat the roots of many plants. The fungi, with their masses of tiny filaments, or mycelia, help the plants absorb soil water and minerals, especially phosphorus. The plants return the favor by providing the fungi with food produced by their photosynthesizing leaves.
If Emily Dickinson had known how Indian pipe obtains its food, I believe she would have been even more impressed with this plant.