Paging through the wildflower guides, I often find particular wildflowers I'd like to see one day. While I'm not so keen as to actively seek them out (though Lewisia rediviva was one of the exceptions), when I do find them, I'm fairly delighted. Encountering Clarkia pulchella for the first time was a pleasant surprise. Searching among the (omnipresent) cheatgrass for plants that may be in seed, I spotted a patch of purple flowers. The general habit of the plant flagged it in my thoughts as “That's different from what I've seen before”, so an immediate investigation was necessary. Having seen it in books and knowing its unique appearance, an immediate identification was made as soon as I was close enough to see the petals.
Clarkia pulchella has several common names, including clarkia, pinkfairy, deerhorn clarkia and ragged robin. The Discovering Lewis and Clark site provides Lewis's description of the plant as well as Pursh's painting for more information about this western North American native.
Curiously, the pollen of Clarkia pulchella helped make an important contribution to science. The phenomenon called Brownian motion, whereby particles suspended in a fluid move randomly, was first observed by botanist Robert Brown in the vacuoles of Clarkia pulchella pollen grains. Brownian motion was eventually used as evidence of the atomic nature of matter (i.e., that matter was composed of atoms and molecules) by Albert Einstein, Jean Perrin and other physicists. Brian J. Ford discusses the discovery in a 1992 paper published in The Microscope (40 (4): 235-241): Brownian Movement in Clarkia Pollen: A Reprise of the First Observations
Photography resource link: if you enjoy photomicrography, Small World from Nikon is likely already on your list of bookmarks. If not, it should be – it showcases some of the best photomicrographs through an annual competition. Even though this year's winners have been chosen (and will be announced in the autumn), a “rate-this-photo” system is in place to reveal if there is any difference between what the judges have chosen and what the public would choose. Thanks to David Brownstein for the suggestion.