. The Canadian field-naturalist. The Canadian Field-Naturalist Vol. 99. Figure 3. Above: Chamaepericlymenum canadense; photo taken in sunlight without filters using Kodak Tri-X film. Below: similar photo of same plants taken through quartz lens and a Kodak Wratten 18A filter which transmits only ultraviolet light and showing the degree of absorption of ultraviolet light rays by the four involucral bracts of each inflorescence. Flower at right is the Common Dandelion, Taraxacum officinale L. included for comparison. Photo by T. Please note that these images are extracted from scanned

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. The Canadian field-naturalist. The Canadian Field-Naturalist Vol. 99. Figure 3. Above: Chamaepericlymenum canadense; photo taken in sunlight without filters using Kodak Tri-X film. Below: similar photo of same plants taken through quartz lens and a Kodak Wratten 18A filter which transmits only ultraviolet light and showing the degree of absorption of ultraviolet light rays by the four involucral bracts of each inflorescence. Flower at right is the Common Dandelion, Taraxacum officinale L. included for comparison. Photo by T. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Ottawa Field-Naturalists' Club. Ottawa, Ottawa Field-Naturalists' Club

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